News: Hubble plans and policy

[Kent Betts]

http://www.nytimes.com/2003/07/27/science/27HUBB.html?hp
As Clock Ticks for Hubble, Some Plead for a Reprieve
By DENNIS OVERBYE


One astronomer compared it to the fate of the faithful dog in the movie "Old
Yeller." On Thursday, astronomers will crowd into a hotel ballroom in Washington
to discuss when and how NASA should put down one of its and astronomy's most
spectacular successes, the Hubble Space Telescope.

Since it was launched in 1990 with a flawed mirror and then repaired by
spacewalking astronauts, the Hubble, floating above the murky atmosphere, has
been a matchless time machine, providing astronomers with views of unprecedented
clarity deep into space and time. "The Hubble is the single most important
instrument ever made in astronomy," said Dr. Sandra Faber, an astronomer at the
University of California at Santa Cruz.

But its days (and nights) have always been numbered. NASA has long planned to
end Hubble's spectacular run and bring it down in 2010 to make way in the budget
for the James Webb Space Telescope, scheduled to be launched in 2011.

Still, some astronomers are urging that Hubble's life be extended. They argue
that the telescope has grown even more productive in its years in orbit, thanks
to periodic service calls by astronauts.

These astronomers say that killing Hubble in its prime makes little sense,
either scientifically or from the standpoint of public relations. "Hubble is by
far the best news NASA has now," a senior astronomer said.

An extension of Hubble's life, they say, will ensure that there is no gap in
coverage before the Webb telescope goes into operation, but it would require an
extra shuttle visit to Hubble late in the decade. That would cost at least $600
million, said Dr. Anne L. Kinney, director of astronomy and physics in NASA's
Office of Space Science, and the money would have to come at the expense of the
Webb telescope or some other project.

As a result, whatever NASA does is bound to make someone unhappy. "It's terribly
important," Dr. Kinney said. "There is a lot of anxiety in the astronomical
community about it. You have to listen to them."

Dr. Kinney has appointed a panel of scientists led by Dr. John Bahcall, an
astrophysicist at the Institute of Advanced Study in Princeton, N.J., to
evaluate NASA's plans for Hubble and to see if there is justification for a
change. "Our charge is to advise about how to maximize the science. We are going
to focus on just that task," Dr. Bahcall said.

He called the topic of Hubble's demise "a hot potato," adding, "But someone has
to do it."

The other members of the panel are Dr. Barry Barish of the California Institute
of Technology; Dr. Jacqueline Hewitt of the Massachusetts Institute of
Technology; Dr. Christopher McKee and Dr. Charles Townes, both of the University
of California at Berkeley; and Dr. Martin Rees of Cambridge University in
England.

"They are my dream team," Dr. Bahcall said. "We may catch hell for what we do,
but we will learn a lot while we do it."

The group has set up a Web site (hst-jwst-transition.hq.nasa.gov
/hst-jwst/home.cfm) on which astronomers can post their opinions and read a
growing assortment of policy and fact sheets. It is holding a public meeting at
the Loew's L'Enfant Plaza Hotel in Washington on Thursday.

"It's going to be high opera," Dr. Kinney said.

In an interview, Dr. Edward J. Weiler, NASA's associate administrator in charge
of the Office of Space Science, pointed out that the Hubble's mission had been
extended once. The telescope was originally designed to last 15 years and come
down in 2005.

The next and final astronaut visit to the telescope is scheduled for next year,
but might not happen until 2005 or even 2006, depending on when the shuttles
start flying again in the wake of the loss of the Columbia in February. On that
occasion the telescope will be fitted with two new instruments, and astronomers
say it should work well until the end of the decade.

The decision about what happens then has been complicated by the breakup of the
Columbia. The telescope is too big to leave to fall out of orbit and crash
uncontrollably to Earth on its own. NASA had originally planned to fetch it with
the space shuttle and put it in the Smithsonian's Air and Space Museum, but that
now seems "exceedingly unlikely," in Dr. Kinney's words.

Such a mission would take the shuttle into an orbit in which it could not
rendezvous with the space station if anything went wrong.

Instead NASA is studying the possibility that a robotic rocket could be sent to
attach itself to the telescope and ease it out of orbit safely into the ocean.
That would require developing new technology. If it seems feasible, Dr. Kinney
explained, astronauts could add attachments for the rocket to hook onto during
the upcoming service mission.

The telescope is in no imminent danger even if the next service mission is put
off indefinitely. It is now in an orbit about 350 miles high. How long it could
stay there depends on sunspot activity, which bloats the atmosphere, causing
drag on the telescope. Even under the worst circumstances, Hubble would not fall
until 2013, according to a NASA study. But with a series of small altitude
boosts supplied by the shuttle in 2005 and 2009, it could stay up until 2020 or
beyond.

Leading the charge for another extension are the astronomers of the Space
Telescope Science Institute on the Johns Hopkins campus in Baltimore.

In a policy statement full of statistics testifying to Hubble's dominance of
contemporary astronomy, Dr. Steven V. W. Beckwith, the director of the
institute, argued that as a result of the astronauts' service calls, Hubble had
essentially been reborn every few years, allowing it to stay on top of its game.

"A servicing mission to Hubble is comparable in science value to the launch of a
new satellite and should be judged as such," Dr. Beckwith wrote.

As a result, the number of scientific papers based on Hubble observations still
grows every year.

Dr. Beckwith argued that sending astronauts to fit the telescope with a
propulsion module would be less risky than trying to develop a robot. If such a
trip was necessary, he said, the marginal cost of fixing it up for a few more
years of science would be a bargain.

Dr. Kinney of NASA said the agency was merely following the wishes of the
astronomical community, as expressed in a recent report prepared under the
auspices of the National Academy of Sciences. That report listed what would
become the Webb telescope, designed to probe early cosmic history when galaxies
and stars were first forming, as the highest priority.

"We have to ask, what is the best research for the taxpayer's dollar?" she said.

Dr. Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics said in
an e-mail message that he thought Hubble was working better than it ever had,
"so the equation has changed." He said it would not be easy to decide how best
to serve science.

Dr. Wendy Freedman, director of the Carnegie Observatories in Pasadena, Calif.,
said NASA was asking the right questions with the Bahcall committee. "At some
point, it makes sense to go on and do new things - the risks, budget and promise
of greater potential make this easy to determine," she said. "The question is,
is H.S.T. at this point? Or not?"

Dr. Faber of the University of California said she thought there was a lot of
support to keep Hubble going.

"Hubble is unique. Nothing else can do what it can do," she said. "Once it's
gone, we're going to be paralyzed. We've gotten hooked. We're addicted."

[Charles Buckley]

Dale wrote:
> On Sun, 27 Jul 2003 04:45:52 -0500, "Kent Betts" > wrote:
>
>
>>The decision about what happens then has been complicated by the breakup of the
>>Columbia. The telescope is too big to leave to fall out of orbit and crash
>>uncontrollably to Earth on its own. NASA had originally planned to fetch it with
>>the space shuttle and put it in the Smithsonian's Air and Space Museum, but that
>>now seems "exceedingly unlikely," in Dr. Kinney's words.
>>
>>Such a mission would take the shuttle into an orbit in which it could not
>>rendezvous with the space station if anything went wrong.
>>
>>Instead NASA is studying the possibility that a robotic rocket could be sent to
>>attach itself to the telescope and ease it out of orbit safely into the ocean.
>>That would require developing new technology. If it seems feasible, Dr. Kinney
>>explained, astronauts could add attachments for the rocket to hook onto during
>>the upcoming service mission.
>
>
> OK, what am I missing here? Why is a recovery mission "exceedingly unlikely",
> but future servicing missions are not?
>
> Dale


Recovery? That would mean loading a big heavy Hubble into the
payload bay of a shuttle and returning it to Earth, correct?

I suspect that Hubble would be pushing the return capability of
the Shuttle.

[Dale]

On 27 Jul 2003 11:16:59 GMT, rk > wrote:

>It's the NY Times. It seems that self-contradictions in the paper's
>articles are becoming increasingly common.

Yeah, and the Beeb (BBC) seems to be imploding too. I suppose
one day Fox News will be our most respected source of information.
Arghhh.

>If they could service it, then it could be retrieved. Same risk with
>respect to a non-ISS orbit.
>
>Benefit for retrieval: millions of people get to see it in the museum.
>
Which could inspire many future scientists, and dubunk those who
may claim that it never existed (I suppose there are a few of those).

>Benefit for servicing: a few scientists write papers and do good
>science.
>
>An obvious option not explored by the NYT and something to at least
>consider: If the HST is working better then ever and there is no budget
>for it (moving on to the JWST), why not privatize operations and put the
>whole HST enterprise up for public auction?

Is "good science" profitable enough in the short term for private enterprise?
Who would then pay for its eventual retrieval or deorbiting?

Dale

[Hallerb]

Well Hubble is right now NASA shining star/ Everything else is ill, over budget
or delayed.

My idea do another service mission, boost to a top possible orbit, attach
grapples for a robotic future visit.

When decomishion time comes boost to a much higher orbit stable for at least 50
years. By that time it could come home to a museum. Or bring it back on a
shuttle./

[Paul F. Dietz]

rk wrote:

> It's the NY Times. It seems that self-contradictions in the paper's
> articles are becoming increasingly common.
>
> If they could service it, then it could be retrieved. Same risk with
> respect to a non-ISS orbit.

Display in a museum is a minor benefit, not worth the cost of a launch.

The real justification for retrieval is to avoid dropping debris
on anyone when it reenters. This saves a certain number of lives
on average. If this number is less than the expected number of
lives lost in a shuttle mission, the recovery is not worth doing.

Paul

[Greg D. Moore \(Strider\)]

"Charles Buckley" > wrote in message
...
>
> Recovery? That would mean loading a big heavy Hubble into the
> payload bay of a shuttle and returning it to Earth, correct?
>
> I suspect that Hubble would be pushing the return capability of
> the Shuttle.

Not even close. The shuttle has returned far heavier payloads.


>

[Dale]

On Sun, 27 Jul 2003 06:44:57 -0500, "Paul F. Dietz" > wrote:

>The real justification for retrieval is to avoid dropping debris
>on anyone when it reenters. This saves a certain number of lives
>on average. If this number is less than the expected number of
>lives lost in a shuttle mission, the recovery is not worth doing.

You mean "possible" number, not "expected" number, right?
I'd like to think they always launch with an expected number
of lives lost of "zero".

Dale

I think we've blown $600 million on far less deserving things than
recovering Hubble for the ages...

[Paul F. Dietz]

Dale wrote:

> You mean "possible" number, not "expected" number, right?
> I'd like to think they always launch with an expected number
> of lives lost of "zero".

I mean 'expected' in the sense of the expectation of a random
variable. This value is not necessarily an integer.

Paul

[Hallerb]

>
>No, not everything is perfect but not quite the total disaster you said
>it is. Now, if you can show that "Everything else is ill, over budget
>or delayed" please do so and back up your claim.

True BUT NOTHING ELSE LOOKS AS GOOD TO THE PUBLIC AS HUBBLE!

Nearly everything else is of no interest to most of the public, and beynd that
dont count missions to mars untill they return some results.

You can send hundreds of probes to mars but if they fail at the previious rate
it doesnt look good.

Sorry I exerated to make a point. Ask the average person about most of your
list. Few will be aware of most of them but nearly everyone will know about
hubble.

[Hallerb]

>News: Hubble plans and policy

Heres a EXCELLENT reason to keep hubble around untill at least the Webb
observatory is operational.

What if Webb is somehow lost?

Then we would have no observatory at all.

[JD]

Thus spake Dale > on Sun, 27 Jul 2003 02:51:03 -0700,
as he held forth on "Re: News: Hubble plans and policy"

>OK, what am I missing here? Why is a recovery mission "exceedingly unlikely",
>but future servicing missions are not?

Could a retrieval be accomplished by an unmanned shuttle mission?

JD
jdkbph <at> snet <dot> net

[Jorge R. Frank]

rk > wrote in
:

> Paul F. Dietz wrote:
>
>> The real justification for retrieval is to avoid dropping debris
>> on anyone when it reenters. This saves a certain number of lives
>> on average. If this number is less than the expected number of
>> lives lost in a shuttle mission, the recovery is not worth doing.
>
> I believe they are required to deorbit the spacecraft safely, I think
> JRF knows those regulations well, what the limits are, and exceptional
> conditions.

Actually... I just know that they exist, plus a few details here and there.
:-)

> One key issue here is if there will be a flight rule of "all flights to
> ISS" for the near and perhaps mid-term. I would guess -- just a
> personal guess -- that this will be a rule for the near term.

Right. The CAIB has recommended that NASA develop tile/RCC
inspection/repair capability. For return-to-flight, this capability can
depend on ISS. However, a "standalone" capability is recommended prior to
the first non-ISS (read: HST) flight.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Jorge R. Frank]

JD > wrote in
:

> Thus spake Dale > on Sun, 27 Jul 2003 02:51:03 -0700,
> as he held forth on "Re: News: Hubble plans and policy"
>
>>OK, what am I missing here? Why is a recovery mission "exceedingly
>>unlikely", but future servicing missions are not?
>
> Could a retrieval be accomplished by an unmanned shuttle mission?

The shuttle does not currently have the capability to fly unmanned. The
blatherings of Joe Barton aside, this capability is not likely to be
developed, either, except possibly unmanned deorbit capability.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[MasterShrink]

>
>OK, what am I missing here? Why is a recovery mission "exceedingly unlikely",
>but future servicing missions are not?

Though maybe there could be some scientific benefit from looking at a bird that
has been up there for what will be about 20 years by 2010...servicing HST is a
necessity...retrieval is not. It would be nice to get the HST down...but I
doubt NASA will take the risk now.

On a side note though, I am worried about how the media is portraying every
non-ISS flight as the riskiest endeavor NASA could undertake. The majority of
those 111 successful shuttle missions did not go to any space station...every
venture into Earth orbit isn't going to be to ISS...

-A.L.

[Henry Spencer]

In article >,
rk > wrote:
>If they could service it, then it could be retrieved...

Not necessarily. This is why the loss of Columbia, in particular, is a
problem for a retrieval mission: Columbia was the only remaining orbiter
with an unobstructed cargo bay. Hubble is (if I'm not mistaken) too big
to fit in the cargo bay together with the external airlock/docking-port
assembly that the other orbiters now have in there. They can fly a
servicing mission, but would need extensive reworking to fly a retrieval
(and then after the retrieval, you get to rework that orbiter again to put
things back the way they were).

>An obvious option not explored by the NYT and something to at least
>consider: If the HST is working better then ever and there is no budget
>for it (moving on to the JWST), why not privatize operations and put the
>whole HST enterprise up for public auction?

A private operator is going to want to see revenue from HST operations.
If you zero out NASA's HST-operations budget, then where, exactly, would
that revenue come from? (The astronomy community does not have hundreds
of millions to spend on buying data from such a venture.)
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Doug...]

In article >,
says...
>
> <snip>
>
> Yeah, and the Beeb (BBC) seems to be imploding too. I suppose
> one day Fox News will be our most respected source of information.

Only if you're somewhere to the right of Attila the Hun, politically.

> Arghhh.

Agreed.

--

It's not the pace of life I mind; | Doug Van Dorn
it's the sudden stop at the end... |

[MasterShrink]

>The risk is the same for the first two options. For the third option, you
>are trading a certain amount of astronaut risk for a certain amount of
>third-party risk. The astronauts sign up for the risks they take. Innocent
>third parties don't get to either sign up, or opt out. The choice is
>fairly clear to me.

It really depends on what NASA decides the public is more afraid of...letting
HST come down uncontrolled or losing a shuttle on a solo-Earth orbit mission.

If they let HST burn up, out of control we get days of media coverage to "watch
out because HST might hit you, the idiots at NASA didn't go get it!" and if one
screw survives re-entry we'll here how deadly it could have been from
"experts".

If NASA launches a shuttle to either bring HST home or boost it to a higher
orbit I guess the media will trump it up as a "risky" mission and either be
hard on NASA and state "oh, but the odds of Hubble landing on someone's head
are a billion to one" or call it a heroic endeavor.

And if we lose a shuttle on such a mission I'm sure we'll hear endless
ramblings along the lines of "they should have just let it burn up."

I hate the media...

-A.L.

[Jorge R. Frank]

OM <om@our_blessed_lady_mary_of_the_holy_NASA_research _facility.org>
wrote in :

> On Sun, 27 Jul 2003 04:45:52 -0500, "Kent Betts"
> wrote:
>
>>Instead NASA is studying the possibility that a robotic rocket could
>>be sent to attach itself to the telescope and ease it out of orbit
>>safely into the ocean.
>
> ...Now *here's* where nobody's thinking over there. If they can launch
> a de-orbit retro, why can't they simply use it to change the orbital
> plane and allow a Shuttle to retrieve it *and* still retain ISS
> capabilities?

A deorbit burn from HST's altitude requires a delta-V of around 150 m/s.

A plane change from HST to ISS requires a minimum delta-V of around 3,000
m/s.

> Gah.

Gah to you, too.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Mary Shafer]

On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> wrote:

> Recovery? That would mean loading a big heavy Hubble into the
> payload bay of a shuttle and returning it to Earth, correct?
>
> I suspect that Hubble would be pushing the return capability of
> the Shuttle.

Er, Hubble was launched in the Orbiter and the Orbiter never carries
anything it can't land with safely. Otherwise the abort modes would
be impossible.

Mary

--
Mary Shafer Retired aerospace research engineer

"A MiG at your six is better than no MiG at all."
Anonymous US fighter pilot

[OM]

On Sun, 27 Jul 2003 04:45:52 -0500, "Kent Betts"
> wrote:

>Instead NASA is studying the possibility that a robotic rocket could be sent to
>attach itself to the telescope and ease it out of orbit safely into the ocean.

....Now *here's* where nobody's thinking over there. If they can launch
a de-orbit retro, why can't they simply use it to change the orbital
plane and allow a Shuttle to retrieve it *and* still retain ISS
capabilities?

Gah.


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[OM]

On 27 Jul 2003 11:16:59 GMT, rk >
wrote:

>It's the NY Times. It seems that self-contradictions in the paper's
>articles are becoming increasingly common.

....That's what they get for plagiarizing from multiple sources,
instead of picking one crackpot and sticking with whatever drivel
they're vomiting all over the topic in question.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[Jorge R. Frank]

Mary Shafer > wrote in
:

> On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> wrote:
>
>> Recovery? That would mean loading a big heavy Hubble into the
>> payload bay of a shuttle and returning it to Earth, correct?
>>
>> I suspect that Hubble would be pushing the return capability of
>> the Shuttle.
>
> Er, Hubble was launched in the Orbiter and the Orbiter never carries
> anything it can't land with safely. Otherwise the abort modes would
> be impossible.

That was my answer, too... I've since learned that only the "nominal"
landing weight/CG limits are certified for multiple landings; the "abort"
limits are certified for one time only. That doesn't mean the airframe is a
write-off after an abort landing, but it does mean NASA would want to go
over it a little more thoroughly than normal.

Hubble definitely falls under the nominal landing weight limit; it's only
24,500 lb, well under half the shuttle's lift capacity. I'm not sure about
the CG limit, but as you say, it has to be within the abort limit or they
wouldn't have launched it in the first place.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Jorge R. Frank]

(Henry Spencer) wrote in
:

> In article >,
> rk > wrote:
>>If they could service it, then it could be retrieved...
>
> Not necessarily. This is why the loss of Columbia, in particular, is
> a problem for a retrieval mission: Columbia was the only remaining
> orbiter with an unobstructed cargo bay. Hubble is (if I'm not
> mistaken) too big to fit in the cargo bay together with the external
> airlock/docking-port assembly that the other orbiters now have in
> there. They can fly a servicing mission, but would need extensive
> reworking to fly a retrieval...

Right. Not a show-stopper but definitely a cost driver.

> (and then after the retrieval, you get to
> rework that orbiter again to put things back the way they were).

NASA can avoid the post-flight mod by doing the retrieval mission on an
orbiter slated to be retired after the flight anyway (which was the
original plan for Columbia after the HST retrieval mission, in 2009 or so).

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[LooseChanj]

On or about 27 Jul 2003 22:04:58 GMT, Jorge R. Frank >
made the sensational claim that:
> A plane change from HST to ISS requires a minimum delta-V of around 3,000
> m/s.

Pfthp! That's only half of what a plane change at the Atlanta airport needs.
--
This is a siggy | To E-mail, do note | This space is for rent
It's properly formatted | who you mean to reply-to | Inquire within if you
No person, none, care | and it will reach me | Would like your ad here

[Charles Buckley]

Mary Shafer wrote:
> On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> > wrote:
>
>
>> Recovery? That would mean loading a big heavy Hubble into the
>>payload bay of a shuttle and returning it to Earth, correct?
>>
>> I suspect that Hubble would be pushing the return capability of
>>the Shuttle.
>
>
> Er, Hubble was launched in the Orbiter and the Orbiter never carries
> anything it can't land with safely. Otherwise the abort modes would
> be impossible.
>
> Mary
>


I really should quit responding with short notes.

The other vehicles all have had modifications which have different
constraints now than when the Hubble was originally launched. The return
would have Hubble with it's CG located in a rather different location
than what it had when it was launched in the first place. They either
need to remodify the Shuttle's to match the original config, or they
need to look long and hard at what affect moving the CG will have. My
understanding, which could be wrong, is that the weight limit is also
conditional about where the weight is applied. I am thinking that the
center of the bay has a lot less structural intergrity than the fore
or aft sections.

[Rusty Barton]

On 27 Jul 2003 23:59:31 GMT, "Jorge R. Frank" >
wrote:

>Mary Shafer > wrote in
:
>
>> On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> wrote:
>>
>>> Recovery? That would mean loading a big heavy Hubble into the
>>> payload bay of a shuttle and returning it to Earth, correct?
>>>
>>> I suspect that Hubble would be pushing the return capability of
>>> the Shuttle.
>>
>> Er, Hubble was launched in the Orbiter and the Orbiter never carries
>> anything it can't land with safely. Otherwise the abort modes would
>> be impossible.
>
>That was my answer, too... I've since learned that only the "nominal"
>landing weight/CG limits are certified for multiple landings; the "abort"
>limits are certified for one time only. That doesn't mean the airframe is a
>write-off after an abort landing, but it does mean NASA would want to go
>over it a little more thoroughly than normal.
>
>Hubble definitely falls under the nominal landing weight limit; it's only
>24,500 lb, well under half the shuttle's lift capacity. I'm not sure about
>the CG limit, but as you say, it has to be within the abort limit or they
>wouldn't have launched it in the first place.


If they choose not to recover the Hubble, they should take pictures of
currently restricted objects. Hubble should do a survey of Mercury
(currently a restricted object because it is never very far from the
glare of the Sun).





--
Rusty Barton - Antelope, California |"Every so often, I like to
Visit my Titan I ICBM website at: | stick my head out the window,
http://www.geocities.com/titan_1_missile | look up, and smile for the
| satellite picture."-Steven Wright

[Henry Spencer]

In article >,
Jorge R. Frank > wrote:
>> (and then after the retrieval, you get to
>> rework that orbiter again to put things back the way they were).
>
>NASA can avoid the post-flight mod by doing the retrieval mission on an
>orbiter slated to be retired after the flight anyway (which was the
>original plan for Columbia after the HST retrieval mission, in 2009 or so).

However, it was easy to talk about retiring Columbia, since it was the
oldest orbiter and also (by a considerable margin) the least capable.
There's no such obvious victim any more, and with the fleet down to three,
I doubt that anyone is going to seriously contemplate any retirements
until the whole shuttle program is on the brink of retirement.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Jorge R. Frank]

Charles Buckley > wrote in
:

> The other vehicles all have had modifications which have different
> constraints now than when the Hubble was originally launched. The return
> would have Hubble with it's CG located in a rather different location
> than what it had when it was launched in the first place. They either
> need to remodify the Shuttle's to match the original config, or they
> need to look long and hard at what affect moving the CG will have.

Oh, they will, they will. The flight design process for every shuttle
flight includes calculation of sequential mass properties (mass, CG, and
moments/products of inertia) for every major event in the flight, from
launch to landing, accounting for the unique config of each orbiter and the
depletion of propellants and other consumables, for both the nominal
mission and all intact abort modes.

> My
> understanding, which could be wrong, is that the weight limit is also
> conditional about where the weight is applied. I am thinking that the
> center of the bay has a lot less structural intergrity than the fore
> or aft sections.

Yes, that would be the CG limit. The orbiter is rather fussy about the CG
location during entry/landing.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Brian Thorn]

On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> wrote:


> Recovery? That would mean loading a big heavy Hubble into the
>payload bay of a shuttle and returning it to Earth, correct?
>
> I suspect that Hubble would be pushing the return capability of
>the Shuttle.

Nope, it's around 24,000 lbs., about the same as Spacelab, and
significantly less than Spacelabs that flew with the EDO pallet.

Brian

[Reed Snellenberger]

(Henry Spencer) wrote in
:


>
> Not necessarily. This is why the loss of Columbia, in particular, is
> a problem for a retrieval mission: Columbia was the only remaining
> orbiter with an unobstructed cargo bay. Hubble is (if I'm not
> mistaken) too big to fit in the cargo bay together with the external
> airlock/docking-port assembly that the other orbiters now have in
> there. They can fly a servicing mission, but would need extensive
> reworking to fly a retrieval (and then after the retrieval, you get to
> rework that orbiter again to put things back the way they were).
>

This assumes that they don't remove all or part of the barrel/sunshade to
make it fit. Since the upper structure is a carbon-fiber lattice under a
cover, I imagine it would be pretty easy to cut through with the right
tool.

If the choice is between not retrieving the Hubble (because they don't want
to install the internal airlock for just one mission), or retrieving all
but xx feet of the Hubble (with the remainder "restored" for purposes of
display at the Smithsonian), I'd vote for bringing back as much as they
can.

--
Reed Snellenberger

[Jorge R. Frank]

(Henry Spencer) wrote in
:

> In article >,
> Jorge R. Frank > wrote:
>>> (and then after the retrieval, you get to
>>> rework that orbiter again to put things back the way they were).
>>
>>NASA can avoid the post-flight mod by doing the retrieval mission on
>>an orbiter slated to be retired after the flight anyway (which was the
>>original plan for Columbia after the HST retrieval mission, in 2009 or
>>so).
>
> However, it was easy to talk about retiring Columbia, since it was the
> oldest orbiter and also (by a considerable margin) the least capable.
> There's no such obvious victim any more, and with the fleet down to
> three, I doubt that anyone is going to seriously contemplate any
> retirements until the whole shuttle program is on the brink of
> retirement.

Right. So that either means stretching out Hubble lifetime to match the
anticipated retirement of the shuttle fleet in 2020, or accelerating the
retirement of the shuttle fleet to 2010 or so (which would add considerable
urgency to OSP).

Stay tuned; all of the above are players in the debate which will occur
this autumn.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Jorge R. Frank]

rk > wrote in
:

> Now, I don't
> recall exactly, but what was the configuration of Columbia supposed to
> be for its station mission and then the last HST one?

For the station mission (STS-118/ISS-13A.1), Columbia's payload bay config
was as follows (forward-to-aft): tunnel adapter, external airlock, docking
system, another tunnel adapter, Spacehab single module, then a lightweight
cargo carrier truss for the return of the Early Ammonia Servicer (EAS) from
ISS.

For the Hubble servicing mission (HST SM-04), Columbia was to have carried
an integrated cargo carrier, and the Hubble flight servicing structure.

For the Hubble retrieval mission, Columbia was to have an empty payload
bay.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Mary Shafer]

On 27 Jul 2003 23:59:31 GMT, "Jorge R. Frank" >
wrote:

> Mary Shafer > wrote in
> :
>
> > On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> > wrote:
> >
> >> Recovery? That would mean loading a big heavy Hubble into the
> >> payload bay of a shuttle and returning it to Earth, correct?
> >>
> >> I suspect that Hubble would be pushing the return capability of
> >> the Shuttle.
> >
> > Er, Hubble was launched in the Orbiter and the Orbiter never carries
> > anything it can't land with safely. Otherwise the abort modes would
> > be impossible.
>
> That was my answer, too... I've since learned that only the "nominal"
> landing weight/CG limits are certified for multiple landings; the "abort"
> limits are certified for one time only. That doesn't mean the airframe is a
> write-off after an abort landing, but it does mean NASA would want to go
> over it a little more thoroughly than normal.

This is my understanding, too. Of course, this is pretty much
standard procedure for any vehicle. The main reason for this for the
Orbiter is there's no good way to dump the OMS fuel in an abort,
unlike most aircraft, so they have to land at a heavier weight
aborting than they would in a regular landing.

Normally, an airplane will fly around and burn off or dump enough fuel
to get it down well within the landing weight limits, mostly so it
will stop before the end of the runway without setting the tires,
wheels, and brakes, or even the entire aircraft, on fire. Yes,
aircraft are certified to land at GTOW on a normal-length runway
without any flames, but those tests assume a highly-trained test pilot
with plenty of practice, optimal energy management, and a clean, dry
runway. Still, I'd rather do an immediate 180 in an airliner and land
heavy than do an RTLS or a TAL. An AOA doesn't seem as dicey, though.

> Hubble definitely falls under the nominal landing weight limit; it's only
> 24,500 lb, well under half the shuttle's lift capacity. I'm not sure about
> the CG limit, but as you say, it has to be within the abort limit or they
> wouldn't have launched it in the first place.

I'm sure about the CG limits because my husband was on the group that
set the CG envelope. Hubble is well within the envelope. I just
asked him. Some references are easy to find, rather than being packed
away in a carton somewhere.

Mary

--
Mary Shafer Retired aerospace research engineer

"A MiG at your six is better than no MiG at all."
Anonymous US fighter pilot

[Charles Buckley]

Jorge R. Frank wrote:
> OM <om@our_blessed_lady_mary_of_the_holy_NASA_research _facility.org>
> wrote in :
>
>
>>On Sun, 27 Jul 2003 04:45:52 -0500, "Kent Betts"
> wrote:
>>
>>
>>>Instead NASA is studying the possibility that a robotic rocket could
>>>be sent to attach itself to the telescope and ease it out of orbit
>>>safely into the ocean.
>>
>>...Now *here's* where nobody's thinking over there. If they can launch
>>a de-orbit retro, why can't they simply use it to change the orbital
>>plane and allow a Shuttle to retrieve it *and* still retain ISS
>>capabilities?
>
>
> A deorbit burn from HST's altitude requires a delta-V of around 150 m/s.
>
> A plane change from HST to ISS requires a minimum delta-V of around 3,000
> m/s.
>
>
>>Gah.
>
>
> Gah to you, too.
>


I have to wonder what other side affects of the Columbia report might
have. I think above you state a very clear case for one thing: Will the
new operational rules for Shuttle have room for any missions outside
the ISS orbit? It seems to me that only the ISS orbit has viable
alternatives in terms of being able to sustain support for a damaged
shuttle. (I am not advocating said constraints, but I would be very
surprised if that is not on the table somewhere, if only to keep the
engineers and PR flacks from having to answer the same questions over,
and over, again).

[Mary Shafer]

On 28 Jul 2003 02:22:24 GMT, rk >
wrote:

> Exactly. It is unfortunate but it appears that there is not enough
> money in the NASA budget to support everything forever.

Good thing, too, or we'd still be flying those high-maintenance
F-104Gs. I did everything I could to keep the TF-104G with the folded
optical window flying for another month, but Dryden couldn't afford
either the custom production of pyros or the engine overhaul (each
about a quarter of a million dollars) on an airplane that was so old
we were having to fabricate parts rather than getting replacements
from supply.

Mary

--
Mary Shafer Retired aerospace research engineer

"A MiG at your six is better than no MiG at all."
Anonymous US fighter pilot

[Jorge R. Frank]

Charles Buckley > wrote in
:

> Jorge R. Frank wrote:
>>
>> A deorbit burn from HST's altitude requires a delta-V of around 150
>> m/s.
>>
>> A plane change from HST to ISS requires a minimum delta-V of around
>> 3,000 m/s.
>
> I have to wonder what other side affects of the Columbia report
> might
> have. I think above you state a very clear case for one thing: Will
> the new operational rules for Shuttle have room for any missions
> outside the ISS orbit? It seems to me that only the ISS orbit has
> viable alternatives in terms of being able to sustain support for a
> damaged shuttle. (I am not advocating said constraints, but I would be
> very surprised if that is not on the table somewhere, if only to keep
> the engineers and PR flacks from having to answer the same questions
> over, and over, again).

Even prior to STS-107, the only non-ISS flights on the long-term shuttle
manifest were to HST. So this question really boils down to, "whither HST?"

The two main considerations behind the question are the ability of ISS to
support a stranded shuttle crew, and capability to perform tile/RCC
inspection/repair. The CAIB has recommended that prior to return-to-
flight, NASA should develop a capability that utilizes ISS capabilities,
and that prior to the first non-ISS flight, NASA should develop a stand-
alone capability.

This recommendation did not come as a surprise to NASA; they had been
working on such a capability since late February. NASA has found that many
of the ISS inspection/repair proposals lend themselves to the standalone
problem as well.

Independent of the CAIB, NASA is studying the capability of ISS to serve as
a "safe haven" for a stranded shuttle crew. But with only four shuttle
flights per year, the ability of ISS to support a shuttle crew until the
next shuttle flight (even with three brought home in the Soyuz) is dubious.

So clearly, while non-ISS flights may involve more risk than ISS flights,
the difference in technical risk is not significant. Certainly I'd be
willing to fly a non-ISS shuttle flight, if they'd let me!

The main risk, as you make clear in your post, is political, not technical.
NASA may well decide that the political risks of performing another HST
servicing mission are too great, given the lack of the "security blanket"
presented by ISS. That would be a tragedy, in my view.

*- see:
http://www.caib.us/news/press_releases/pr030627.html
--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Jorge R. Frank]

Mary Shafer > wrote in
:

> Still, I'd rather do an immediate 180 in an airliner and land
> heavy than do an RTLS or a TAL.

No doubt, especially the period immediately post-ET-sep.

> An AOA doesn't seem as dicey, though.

I agree - the entry profile is a bit more normal and the AOA deorbit burn
gives you a chance to burn off more OMS propellant.

>> Hubble definitely falls under the nominal landing weight limit; it's
>> only 24,500 lb, well under half the shuttle's lift capacity. I'm not
>> sure about the CG limit, but as you say, it has to be within the
>> abort limit or they wouldn't have launched it in the first place.
>
> I'm sure about the CG limits because my husband was on the group that
> set the CG envelope. Hubble is well within the envelope. I just
> asked him. Some references are easy to find, rather than being packed
> away in a carton somewhere.

Thanks, Mary! I definitely did not have that one handy...

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[OM]

On Sun, 27 Jul 2003 21:28:29 -0700, Mary Shafer
> wrote:

>Good thing, too, or we'd still be flying those high-maintenance
>F-104Gs. I did everything I could to keep the TF-104G with the folded
>optical window flying for another month, but Dryden couldn't afford
>either the custom production of pyros or the engine overhaul (each
>about a quarter of a million dollars) on an airplane that was so old
>we were having to fabricate parts rather than getting replacements
>from supply.

[Insert pic of Mary sitting out back of hangar in rocking chair,
whittling a spare part of out of titanium with a pocket knife]


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[Dale]

On Sun, 27 Jul 2003 19:11:23 GMT, Doug... > wrote:

>In article >,
>says...

>> Yeah, and the Beeb (BBC) seems to be imploding too. I suppose
>> one day Fox News will be our most respected source of information.
>
>Only if you're somewhere to the right of Attila the Hun, politically.

I think Attila would be considered a "moderate" today :)

>> Arghhh.
>
>Agreed.

Well, at least the BBC online is very responsive to input from
readers. They currently are running a story on Watergate
conspirator Jeb Magruder claiming that Richard Nixon ordered
the Watergate break in, rather than just covering it up. In their
story, they said Nixon had been impeached. I e-mailed their
handy factual correction address to point out the error, and less
than an hour later they changed "Nixon was impeached and resigned"
to "Threatened by impeachment over the affair, Nixon resigned"

Dale

I fear I'll have a nightmare tonight in which Nixon shakes his
jowls and says "I was not impeached". :)

[Henry Spencer]

In article >,
rk > wrote:
>Agreed. From memory, HST did take up the length of the bay. Not
>inexpensive, but configurations can be changed back. I don't know how
>nasty of a job that is, perhaps Kim is lurking here.

My understanding is that it's a major-overhaul job, not a routine
between-flights job.

>Now, I don't
>recall exactly, but what was the configuration of Columbia supposed to
>be for its station mission and then the last HST one?

My impression -- possibly incorrect -- is that they were going to borrow
the airlock/docking-module assembly from one of the other orbiters for the
station visit, rather than moving Columbia's own airlock out and then back
in for the retrieval.

>...Would the
>general science community think it's a good idea to fund HST through the
>last years of its operational life, in an open peer-reviewed
>competition? I don't think there's any great answer to this question...

The science community in general has never been able to agree on
priorities well enough to give a coherent, never mind great :-), answer to
such a question. The major exception to this, interestingly enough, is
the astronomers... and as noted in the piece that started this thread,
they are currently figuring out their collective opinion on Hubble's
future.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Henry Spencer]

In article >,
Reed Snellenberger > wrote:
>This assumes that they don't remove all or part of the barrel/sunshade to
>make it fit. Since the upper structure is a carbon-fiber lattice under a
>cover, I imagine it would be pretty easy to cut through with the right
>tool.

Unfortunately, the upper end is not *just* barrel, there's a lot of
equipment and other clutter attached. I doubt the practicality of cutting
a section off in orbit.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Mike Dicenso]

On Sun, 28 Jul 2003, Jorge R. Frank wrote:

> (Henry Spencer) wrote in
> :
>
> > In article >,
> > rk > wrote:
> >>If they could service it, then it could be retrieved...
> >
> > Not necessarily. This is why the loss of Columbia, in particular, is
> > a problem for a retrieval mission: Columbia was the only remaining
> > orbiter with an unobstructed cargo bay. Hubble is (if I'm not
> > mistaken) too big to fit in the cargo bay together with the external
> > airlock/docking-port assembly that the other orbiters now have in
> > there. They can fly a servicing mission, but would need extensive
> > reworking to fly a retrieval...
>
> Right. Not a show-stopper but definitely a cost driver.

That can't be right. The Hubble is approximately 43 feet (13.1 meters)
long, which is about the same length as most of the ISS truss sections
launched so far. In fact, I believe that the PV6 truss and solar arrays
topped out around 49 feet, te absolute maximum length that anything can be
in orbiters equipped with an ODS assembly. So, no mods needed for any
orbiter going up on an HST retrieval mission.
-Mike

[Reed Snellenberger]

(Henry Spencer) wrote in
:

> In article >,
> Reed Snellenberger > wrote:
>>This assumes that they don't remove all or part of the barrel/sunshade
>>to make it fit. Since the upper structure is a carbon-fiber lattice
>>under a cover, I imagine it would be pretty easy to cut through with
>>the right tool.
>
> Unfortunately, the upper end is not *just* barrel, there's a lot of
> equipment and other clutter attached. I doubt the practicality of
> cutting a section off in orbit.

Henry:

I couldn't find a detailed (dimensioned) plan for the telescope, but the
diagram located at:

http://hubble.gsfc.nasa.gov/technology/parts.html

appears to show that the truss structure (including the secondary mirror
and the other 'clutter') ends approximately 7-9' from the end of
telescope itself. Assuming that the aperture door is designed with a
local motor connected to the telescope over a cable, it looks like there
isn't much there to get in the way.

You'd clearly need a NASA-spec pair of tinsnips (or equivalent), but
we've got several years to get that built. I assume that a 30' length
of primacord wouldn't be acceptable...

Just a thought.

--
Reed Snellenberger

[Doug...]

In article >,
says...
>
> <snip>
>
> Well, at least the BBC online is very responsive to input from
> readers. They currently are running a story on Watergate
> conspirator Jeb Magruder claiming that Richard Nixon ordered
> the Watergate break in, rather than just covering it up. In their
> story, they said Nixon had been impeached. I e-mailed their
> handy factual correction address to point out the error, and less
> than an hour later they changed "Nixon was impeached and resigned"
> to "Threatened by impeachment over the affair, Nixon resigned"

Articles of impeachment against Nixon were passed by the appropriate
House committee and sent to the floor of the House. Nixon resigned when
it became apparent that articles would be approved by the House and that
he didn't have enough votes in the Senate to win the trial. So, the
original BBC wording was indeed wrong and the corrected version, prompted
by your comment, was more correct. But it was more than just a threat --
it was pretty much guaranteed that Nixon would lose if he allowed the
process to continue. Otherwise, he wouldn't have resigned.

--

It's not the pace of life I mind; | Doug Van Dorn
it's the sudden stop at the end... |

[Brian Thorn]

On 28 Jul 2003 02:22:24 GMT, rk >
wrote:

>Henry Spencer wrote:
>
>> In article >,
>> rk > wrote:
>>>If they could service it, then it could be retrieved...
>>
>> Not necessarily. This is why the loss of Columbia, in particular,
>> is a problem for a retrieval mission: Columbia was the only
>> remaining orbiter with an unobstructed cargo bay. Hubble is (if
>> I'm not mistaken) too big to fit in the cargo bay together with the
>> external airlock/docking-port assembly that the other orbiters now
>> have in there. They can fly a servicing mission, but would need
>> extensive reworking to fly a retrieval (and then after the
>> retrieval, you get to rework that orbiter again to put things back
>> the way they were).
>
>Agreed. From memory, HST did take up the length of the bay.

Hubble measures 43.5 feet in length and 14 feet in diameter, so it
should fit within the 15 x 60 ft payload bay, even with the external
airlock. But it will be close.

Brian

[Brian Thorn]

On 28 Jul 2003 05:56:21 GMT, "Jorge R. Frank" >
wrote:

>Charles Buckley > wrote in
:


>Independent of the CAIB, NASA is studying the capability of ISS to serve as
>a "safe haven" for a stranded shuttle crew. But with only four shuttle
>flights per year, the ability of ISS to support a shuttle crew until the
>next shuttle flight (even with three brought home in the Soyuz) is dubious.

If there is a serious problem with an Orbiter that prevents its safe
return, is NASA seriously going to consider launching a second
Orbiter? Look how long we're standing-down because of 107, 13 months
at the minimum, and it was pretty clear what felled Columbia within a
couple of weeks. Therefore, the idea of retrieving the Safe Haven crew
with another Shuttle would appear to be illogical. Unless NASA is
planning to fund increased Soyuz production, or magically acellerate
OSP production, the "Safe Haven" concept would seem to be a band-aid
applied to a severed artery. ISS can be a repair facility, perhaps. A
Safe Haven is not in the cards.

And why only four flights a year? The schedule was five per year
pre-107. With each Orbiter easily capable of three flights per year,
even a two-Orbiter fleet (with one in OMM) can support six flights per
year.

Brian

[Charles Buckley]

Henry Spencer wrote:
> In article >,
> Charles Buckley > wrote:
>
>>...My understanding, which could be wrong, is that the weight limit is also
>>conditional about where the weight is applied. I am thinking that the
>>center of the bay has a lot less structural intergrity than the fore
>>or aft sections.
>
>
> The issue is not structural strength, but flying behavior. The orbiter
> has to function as an aircraft for descent and landing, and so the
> position of its overall center of mass is quite important if stability and
> control are to be satisfactory. Mary could doubtless explain the details
> better than I could. :-)
>


She stated that the weight was within the CG limits, but I am not
sure if she was referring to the modified length of the payload bay
with the docking ring. Someone put the length on here and it was less
than the length of the bay with the adapter, but I could be mistaken.
This is not something they can just move around the bay. In it's
original launch, was HST fore, center, or aft in the bay? With the
adapter, the loading would be rather different than what the launch
config had.

> A light payload can go almost anywhere, but a heavy one's center of mass
> must be within a small volume (which does not include the geometric center
> of the cargo bay -- something that really annoyed payload designers,
> because tightly-packed payloads generally have their center of mass quite
> close to their geometric center, and changing that is not easy).
>
> In any case, Hubble fills essentially the entire cargo bay, and its own
> center of mass has not changed much since launch, so that question is
> pretty much moot. The problem is clearing the cargo bay -- not an easy
> task for the remaining orbiters, which have had the airlock moved out of
> the cabin. (The presence of an airlock is non-negotiable, even on a
> flight with no scheduled spacewalks, because it is required for certain
> emergency procedures.)

So, even with the adapter taken off, then had the HST been launched
foreward in the bay, there is a good chance this would push it aft. Hmm.
Winging this.. Given the design contraint that the CG was not located
near the center of the Bay, they would likely have designed HST with
an off-center mass that was far enough towards one end of the HST that
it could be mounted center and still have it's CG outside the limits of
the bay. Now, if the original launch config had been aft with the CG
on the foreward side, then this would not be affected much by adding an
airlock into the bay. But, if it was mounted in the middle with a
foreward CG, then shifting it aft could put it's CG into the center of
the bay.

This mission is impossible without an airlock, so that really does put
in that constraint.

[Charles Buckley]

Mary Shafer wrote:
> On 27 Jul 2003 23:59:31 GMT, "Jorge R. Frank" >
> wrote:
>
>
>>Mary Shafer > wrote in
:
>>
>>
>>>On Sun, 27 Jul 2003 05:11:47 -0600, Charles Buckley
> wrote:
>>>
>>>
>>>> Recovery? That would mean loading a big heavy Hubble into the
>>>>payload bay of a shuttle and returning it to Earth, correct?
>>>>
>>>> I suspect that Hubble would be pushing the return capability of
>>>>the Shuttle.
>>>
>>>Er, Hubble was launched in the Orbiter and the Orbiter never carries
>>>anything it can't land with safely. Otherwise the abort modes would
>>>be impossible.
>>
>>That was my answer, too... I've since learned that only the "nominal"
>>landing weight/CG limits are certified for multiple landings; the "abort"
>>limits are certified for one time only. That doesn't mean the airframe is a
>>write-off after an abort landing, but it does mean NASA would want to go
>>over it a little more thoroughly than normal.
>
>
> This is my understanding, too. Of course, this is pretty much
> standard procedure for any vehicle. The main reason for this for the
> Orbiter is there's no good way to dump the OMS fuel in an abort,
> unlike most aircraft, so they have to land at a heavier weight
> aborting than they would in a regular landing.
>
> Normally, an airplane will fly around and burn off or dump enough fuel
> to get it down well within the landing weight limits, mostly so it
> will stop before the end of the runway without setting the tires,
> wheels, and brakes, or even the entire aircraft, on fire. Yes,
> aircraft are certified to land at GTOW on a normal-length runway
> without any flames, but those tests assume a highly-trained test pilot
> with plenty of practice, optimal energy management, and a clean, dry
> runway. Still, I'd rather do an immediate 180 in an airliner and land
> heavy than do an RTLS or a TAL. An AOA doesn't seem as dicey, though.
>
>
>>Hubble definitely falls under the nominal landing weight limit; it's only
>>24,500 lb, well under half the shuttle's lift capacity. I'm not sure about
>>the CG limit, but as you say, it has to be within the abort limit or they
>>wouldn't have launched it in the first place.
>
>
> I'm sure about the CG limits because my husband was on the group that
> set the CG envelope. Hubble is well within the envelope. I just
> asked him. Some references are easy to find, rather than being packed
> away in a carton somewhere.
>
> Mary
>


Henry keeps mentioning modifications to be the Bay since that time.
One of the things he mentions is the adapter. The other an external
airlock. Would either of these shift the mounting point of the HST from
it's launch config? Also, is the CG limits applicable across the whole
vehicle, or limitted to specific sections of the bay? If the HST can not
be mounted in it's original config, then this is a whole new set of
variables to be weighed. It could easily have been shifted outside the
CG envelope should there have been the wrong types of mods since the
original launch.

From what I am seeing, they can not just take the original numbers
because the variable is not the Hubble, but the launch vehicle.

[Mary Shafer]

On Mon, 28 Jul 2003 21:01:57 -0600, Charles Buckley
> wrote:

> Henry Spencer wrote:
> > In article >,
> > Charles Buckley > wrote:
> >
> >>...My understanding, which could be wrong, is that the weight limit is also
> >>conditional about where the weight is applied. I am thinking that the
> >>center of the bay has a lot less structural intergrity than the fore
> >>or aft sections.
> >
> >
> > The issue is not structural strength, but flying behavior. The orbiter
> > has to function as an aircraft for descent and landing, and so the
> > position of its overall center of mass is quite important if stability and
> > control are to be satisfactory. Mary could doubtless explain the details
> > better than I could. :-)

> She stated that the weight was within the CG limits, but I am not
> sure if she was referring to the modified length of the payload bay
> with the docking ring.

I said the CG was within the CG limits and the weight was within the
weight limits.

The way you do the CG is to take the mass and CG position of the added
item (Hubble, in this case) and multiply the mass times the moment arm
between the vehicle CG and the item CG and add it to the vehicle CG to
get the new CG. If that CG is within limits, everything's fine.

If you can get Hubble into the payload bay, the new CG will be within
the limits.

> Someone put the length on here and it was less
> than the length of the bay with the adapter, but I could be mistaken.
> This is not something they can just move around the bay. In it's
> original launch, was HST fore, center, or aft in the bay?

Yes.

> > A light payload can go almost anywhere, but a heavy one's center of mass
> > must be within a small volume (which does not include the geometric center
> > of the cargo bay -- something that really annoyed payload designers,
> > because tightly-packed payloads generally have their center of mass quite
> > close to their geometric center, and changing that is not easy).
> >
> > In any case, Hubble fills essentially the entire cargo bay, and its own
> > center of mass has not changed much since launch, so that question is
> > pretty much moot. The problem is clearing the cargo bay -- not an easy
> > task for the remaining orbiters, which have had the airlock moved out of
> > the cabin. (The presence of an airlock is non-negotiable, even on a
> > flight with no scheduled spacewalks, because it is required for certain
> > emergency procedures.)
>
> So, even with the adapter taken off, then had the HST been launched
> foreward in the bay, there is a good chance this would push it aft. Hmm.

Nope. Adding something with a forward CG moves the CG forward. How
much depends on how heavy the item is and where its CG is.

> Winging this.. Given the design contraint that the CG was not located
> near the center of the Bay, they would likely have designed HST with
> an off-center mass that was far enough towards one end of the HST that
> it could be mounted center and still have it's CG outside the limits of
> the bay.

No, they couldn't. The CG is well within the payload bay. In fact,
it's on the centerline laterally, it's at about the mid waterline, and
it's somewhere around 30% MAC (although that's arbitrary because of
the way they define MAC, but that's never bothered anyone).

No matter what you put in the payload bay, if its CG is anywhere near
its geometrical center and it mostly fills the bay, the CG won't move
that much.

By the way, the Orbiter CG is, roughly, in the middle of the Orbiter.
It's just that the payload bay isn't. We don't care about the CG of
the payload pay or the payload, except in how the payload CG and mass
affect the Orbiter CG.

The Orbiter CG envelope is pretty robust. It's not a limited to a few
inches longitudinally. It's more like a few feet. Ditto laterally
and vertically. The Orbiter is a big vehicle with big control
surfaces and a big body flap to trim with.

>Now, if the original launch config had been aft with the CG
> on the foreward side, then this would not be affected much by adding an
> airlock into the bay. But, if it was mounted in the middle with a
> foreward CG, then shifting it aft could put it's CG into the center of
> the bay.

You don't get it. We don't care about Hubble's CG. It's not
important. It's just riding along in the Orbiter.

We care only about the Orbiter's CG. It's very important. Why?
Dynamic stability, static stability, control authority, trim
capability. This all matters when it's flying aerodynamically, not
ballistically. Which is to say, when it's re-entering and landing.

The Orbiter isn't flying aerodynamically during launch.

So all we care about Hubble's CG is that it not move the Orbiter CG
out of the envelope. But we know it won't because we launched it with
the Orbiter, meaning it didn't move it too much.

> This mission is impossible without an airlock, so that really does put
> in that constraint.

--
Mary Shafer Retired aerospace research engineer

"A MiG at your six is better than no MiG at all."
Anonymous US fighter pilot

[Christopher M. Jones]

"Dale" > wrote:
> On Sun, 27 Jul 2003 06:44:57 -0500, "Paul F. Dietz" > wrote:
>
> >The real justification for retrieval is to avoid dropping debris
> >on anyone when it reenters. This saves a certain number of lives
> >on average. If this number is less than the expected number of
> >lives lost in a shuttle mission, the recovery is not worth doing.
>
> You mean "possible" number, not "expected" number, right?
> I'd like to think they always launch with an expected number
> of lives lost of "zero".

Expected value, as in statistics. Probability times magnitude,
more or less. So, say the probability of the Shuttle coming
apart on reentry is 1%, the number of deaths would likely be
about 7, so the expected number of crew deaths per reentry would
be .07. The calculation on the other side is more difficult to
fudge into an easy mold because of the wide variation in possible
number of deaths on the ground in the event of a ground strike
(ranging from zero to a busload, perhaps), but I think you get
the general idea.

[Christopher M. Jones]

"Henry Spencer" > wrote:
> In article >,
> Jorge R. Frank > wrote:
> >> (and then after the retrieval, you get to
> >> rework that orbiter again to put things back the way they were).
> >
> >NASA can avoid the post-flight mod by doing the retrieval mission on an
> >orbiter slated to be retired after the flight anyway (which was the
> >original plan for Columbia after the HST retrieval mission, in 2009 or so).
>
> However, it was easy to talk about retiring Columbia, since it was the
> oldest orbiter and also (by a considerable margin) the least capable.
> There's no such obvious victim any more, and with the fleet down to three,
> I doubt that anyone is going to seriously contemplate any retirements
> until the whole shuttle program is on the brink of retirement.

I think Jorge has the right of it. Frankly, at this point it's
abundantly clear that *all* the orbiters are closer to retirement
than Columbia was (perceived to be) only a few years ago.

[Charles Buckley]

Mary Shafer wrote:
> On Mon, 28 Jul 2003 21:01:57 -0600, Charles Buckley
> > wrote:
>
>
>>Henry Spencer wrote:
>>
>>>In article >,
>>>Charles Buckley > wrote:
>>>
>>>

snip

>
>> She stated that the weight was within the CG limits, but I am not
>>sure if she was referring to the modified length of the payload bay
>>with the docking ring.
>
>
> I said the CG was within the CG limits and the weight was within the
> weight limits.
>
> The way you do the CG is to take the mass and CG position of the added
> item (Hubble, in this case) and multiply the mass times the moment arm
> between the vehicle CG and the item CG and add it to the vehicle CG to
> get the new CG. If that CG is within limits, everything's fine.
>
snip

> No matter what you put in the payload bay, if its CG is anywhere near
> its geometrical center and it mostly fills the bay, the CG won't move
> that much.
>

OK. That is the point where I was headed.

I was not sure how robustly you could move the HST based upon
the moment arm as described above. That is what I was referring
(quite badly) to. I kept hitting that moving it would move the CG
of the payload away from the initial launch config and was not sure
as to how much it would move. I could see a situation where a payload
optimized for a given launch config with a very off-center CG could
actually move the Orbitor CG outside it's envelope if returned mounted
in a different section or orientation in the bay. You have the exact
same caveat above that I used. If the CG is close to the geographic
center, this won't matter much.

I believe you, just wanting to clarify it in my mind. This is why I keep
looking at the payload CG because they could have made design decisions
that would actually lock a payload into a given envelope within the
payload bay - ie, a payload with an offcenter mass that pushed the
overall Orbitor CG towards the either end of the Orbitor CG envelope
could not be shifted further without some implications. Given the
stated changes to the Orbitor, I saw no way to push the payload forward,
only aft. I could see them designing the payload with a CG offset
foreward in the launch config and moving the payload back would move
that CG only into the middle of the bay. But, a payload that was
meant to be launched very forward in the bay with a CG offset to the
aft would have a much larger moment arm. But, as you say, there is not
really enough room to matter. They can not shift it a lot. If the
HST loaded initially was close to the center of the Orbitor CG, then
there is no way to shift it that far.

> By the way, the Orbiter CG is, roughly, in the middle of the Orbiter.
> It's just that the payload bay isn't. We don't care about the CG of
> the payload pay or the payload, except in how the payload CG and mass
> affect the Orbiter CG.
>
> The Orbiter CG envelope is pretty robust. It's not a limited to a few
> inches longitudinally. It's more like a few feet. Ditto laterally
> and vertically. The Orbiter is a big vehicle with big control
> surfaces and a big body flap to trim with.
>
>
>>Now, if the original launch config had been aft with the CG
>>on the foreward side, then this would not be affected much by adding an
>>airlock into the bay. But, if it was mounted in the middle with a
>>foreward CG, then shifting it aft could put it's CG into the center of
>>the bay.
>
>
> You don't get it. We don't care about Hubble's CG. It's not
> important. It's just riding along in the Orbiter.
>
> We care only about the Orbiter's CG. It's very important. Why?
> Dynamic stability, static stability, control authority, trim
> capability. This all matters when it's flying aerodynamically, not
> ballistically. Which is to say, when it's re-entering and landing.
>
> The Orbiter isn't flying aerodynamically during launch.
>
> So all we care about Hubble's CG is that it not move the Orbiter CG
> out of the envelope. But we know it won't because we launched it with
> the Orbiter, meaning it didn't move it too much.
>
>
>> This mission is impossible without an airlock, so that really does put
>>in that constraint.
>
>

[Mike Dicenso]

On Mon, 28 Jul 2003, Charles Buckley wrote:

> Henry Spencer wrote:
> > In article >,
> > Charles Buckley > wrote:
> >
> >>...My understanding, which could be wrong, is that the weight limit is also
> >>conditional about where the weight is applied. I am thinking that the
> >>center of the bay has a lot less structural intergrity than the fore
> >>or aft sections.
> >
> >
> > The issue is not structural strength, but flying behavior. The orbiter
> > has to function as an aircraft for descent and landing, and so the
> > position of its overall center of mass is quite important if stability and
> > control are to be satisfactory. Mary could doubtless explain the details
> > better than I could. :-)
> >
>
>
> She stated that the weight was within the CG limits, but I am not
> sure if she was referring to the modified length of the payload bay
> with the docking ring. Someone put the length on here and it was less
> than the length of the bay with the adapter, but I could be mistaken.
> This is not something they can just move around the bay. In it's
> original launch, was HST fore, center, or aft in the bay? With the
> adapter, the loading would be rather different than what the launch
> config had.


I don't see this as that serious of a problem. A quick check shows that
the Endeavour STS-99 mission not only carried the 14.5 ton Shuttle Radar
Topography hardware, but also the external airlock assembly as well. The
only necessary mod I can see would be to remove the APAS-86 docking
hardware for the mission to allow unobstructed movement of astronauts
through the external airlock's upper hatch once HST is berthed in the
cargo bay.
-Mike

[Brian Thorn]

On Tue, 29 Jul 2003 04:40:57 GMT, Doug... > wrote:

>> Hubble measures 43.5 feet in length and 14 feet in diameter, so it
>> should fit within the 15 x 60 ft payload bay, even with the external
>> airlock. But it will be close.
>
>Ah, but recall that the original config for HST launch had the base of
>the Hubble attached to a deployment table that rotated it from flush with
>the floor of the payload bay to a position 90 degrees from the floor of
>the payload bay. That mechanism needs certain clearances in order to
>operate, and takes up room itself.

No, you're confusing a few things. The Inertial Upper Stage flights
used a tilt table which brought it up to something like 60 degrees
angle to the payload bay for deployment. Hubble was not deployed that
way, it was lifted horizontally out of the payload bay by the RMS. The
servicing missions, however did carry a platform which allowed Hubble
to be rotated around so that different sides faced the forward part of
the payload bay.

Brian

[Doug...]

In article >,
says...
> On Tue, 29 Jul 2003 04:40:57 GMT, Doug... > wrote:
>
> >> Hubble measures 43.5 feet in length and 14 feet in diameter, so it
> >> should fit within the 15 x 60 ft payload bay, even with the external
> >> airlock. But it will be close.
> >
> >Ah, but recall that the original config for HST launch had the base of
> >the Hubble attached to a deployment table that rotated it from flush with
> >the floor of the payload bay to a position 90 degrees from the floor of
> >the payload bay. That mechanism needs certain clearances in order to
> >operate, and takes up room itself.
>
> No, you're confusing a few things. The Inertial Upper Stage flights
> used a tilt table which brought it up to something like 60 degrees
> angle to the payload bay for deployment. Hubble was not deployed that
> way, it was lifted horizontally out of the payload bay by the RMS. The
> servicing missions, however did carry a platform which allowed Hubble
> to be rotated around so that different sides faced the forward part of
> the payload bay.

OK, my memory is playing tricks on me, then. I really thought I
remembered the Hubble being translated within the payload bay to a 90
degree position prior to deployment.

I guess it comes from having seen too many deployments, too many
servicing missions, and too many flights. They begin to run together in
your mind.

However, to the meat of the question -- do we think that it will be easy
to berth the Hubble into the payload bay flush with the floor of the bay?
What if the solar arrays don't eject automatically? Would the crew go
out and work on Hubble while it free-flies next to the orbiter? I would
think that initial berthing in an upright position and *then* laying it
down in the bay would be the way to go...

--

It's not the pace of life I mind; | Doug Van Dorn
it's the sudden stop at the end... |

[Mike Dicenso]

On Tue, 29 Jul 2003, Doug... wrote:

> However, to the meat of the question -- do we think that it will be easy
> to berth the Hubble into the payload bay flush with the floor of the bay?
> What if the solar arrays don't eject automatically? Would the crew go
> out and work on Hubble while it free-flies next to the orbiter? I would
> think that initial berthing in an upright position and *then* laying it
> down in the bay would be the way to go...


All they have to do is hold HST grappled to the end of the RMS in a
position that will allow the astronauts to hook up tethers to the
handholds on the telescope itself, and then translate up to the solar
arrays. Remember that when HST was deployed on STS-31, Kathy Sullivan and
Bruce McCandless almost did an EVA to unfurl the solar arrays. There was
no FSS to berth the HST to at the time. The same will likely be true of
the retrival.
-Mike

[Henry Spencer]

In article >,
Charles Buckley > wrote:
>One of the things he mentions is the adapter. The other an external
>airlock. Would either of these shift the mounting point of the HST from
>it's launch config?

Yes; see other posting. Hubble went up just about at the forward end,
which isn't possible any more with the external airlock.

>Also, is the CG limits applicable across the whole
>vehicle, or limitted to specific sections of the bay?

The real, fundamental requirement is that the CG of the whole vehicle
must be in an acceptable place.

Because most of the parts of the vehicle itself don't move, that
translates almost entirely to a requirement that the overall CG of the
stuff in the cargo bay be in an acceptable place. I say "almost" partly
because there is some small flexibility in how much stuff is loaded into
the cabin, and partly because the relocation of the airlock into the cargo
bay has probably lightened the cabin a bit (thus moving the bare vehicle's
CG aft a bit).

While the presence of the airlock does require that HST go aft in the bay,
the mass of the airlock itself does contribute some to moving the overall
bay-contents CG forward. I suspect it's not enough, however, not with a
tail-heavy Hubble. Barring the possibility of flying with substantial
movable ballast, my guess is that the combination of Hubble and external
airlock just doesn't work.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Brian Thorn]

On Tue, 29 Jul 2003 18:02:29 -0500, Doug... >
wrote:

>However, to the meat of the question -- do we think that it will be easy
>to berth the Hubble into the payload bay flush with the floor of the bay?

They've been doing something very much like that each time they berth
an MPLM to bring it home from the Space Station. Diameter and mass are
about the same, but the MPLM is shorter.

>What if the solar arrays don't eject automatically? Would the crew go
>out and work on Hubble while it free-flies next to the orbiter?

The new solar arrays will have to be removed and probably jettisoned
overboard, which will require a spacewalk. The new arrays fold up
some, but I don't think they'll fit in the payload bay along with
Hubble (unless some fixture can be added to either side of the
external airlock.) For display at the Smithsonian, they'll probably
have to re-install the 1993-2002-era arrays that came back with
STS-109.

Brian

[Doug...]

In article >, says...
>
> <snip>
>
> While the presence of the airlock does require that HST go aft in the bay,
> the mass of the airlock itself does contribute some to moving the overall
> bay-contents CG forward. I suspect it's not enough, however, not with a
> tail-heavy Hubble. Barring the possibility of flying with substantial
> movable ballast, my guess is that the combination of Hubble and external
> airlock just doesn't work.

OK -- so, the solution sounds like either a) de-orbit the Hubble and be
done with it, or b) build a temporary interior airlock to replace the
external airlock on the Hubble return flight. It wouldn't have to be an
expensive module, perhaps portions of the external airlock could be
adapted to fit in the mid-deck, where the old airlock was located.

Sounds like it will be cheaper to design and build a de-orbit module,
doesn't it?

--

Do not meddle in the affair of dragons, for | Doug Van Dorn
thou art crunchy and taste good with ketchup |

[jeff findley]

Doug... > writes:
>
> OK -- so, the solution sounds like either a) de-orbit the Hubble and be
> done with it, or b) build a temporary interior airlock to replace the
> external airlock on the Hubble return flight. It wouldn't have to be an
> expensive module, perhaps portions of the external airlock could be
> adapted to fit in the mid-deck, where the old airlock was located.
>
> Sounds like it will be cheaper to design and build a de-orbit module,
> doesn't it?

You could remove the external airlock and likely re-install one of the
remaining internal airlocks. All three remaining orbiters originally
had internal airlocks which were removed and replaced with new
external airlocks. A quick search of the web seems to indicate that
the internal airlocks weren't destroyed, but were destined for museum
display.

http://www.angelfire.com/fl/Jacqmans/palmdale1.html

Such a modification would surely cost a lot of money, but I wouldn't
think there would be any show-stoppers.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.

[Jorge R. Frank]

Brian Thorn > wrote in
:

> On Wed, 30 Jul 2003 01:51:46 GMT, (Henry Spencer)
> wrote:
>
>
>>However, there is a problem. Hubble's mass is almost all at its rear.
>>So to put the payload center of mass within the acceptable range,
>>Hubble has to go at the *forward* end of the bay -- that's how it went
>>up, with only a minimal spacewalk clearance between its front end and
>>the cabin wall. This is not compatible with the airlock/docking
>>assembly being there on the surviving orbiters. (In fact, that makes
>>the problem worse, since the mass of the airlock used to be farther
>>forward, and so the allowable center-of-mass location for the *rest*
>>of the stuff in the cargo bay has probably moved forward some.)
>
> Hubble launched with the aperture facing forward.
>
> Silly idea... how about loading it in the payload facing aft for
> return? That would put the much-heavier main mirror/instrument section
> well forward of where it was for launch.

Nothing in particular to reply to Brian, but NASAWatch has just posted a
link to an interesting site that may provide a few facts for this
discussion:

http://hst-jwst-transition.hq.nasa.gov/hst-jwst/

In particular:

http://hst-jwst-transition.hq.nasa.gov/hst-jwst/panel_docs.htm

Enjoy!

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Reed Snellenberger]

"Jorge R. Frank" > wrote in
:


>
> Nothing in particular to reply to Brian, but NASAWatch has just posted a
> link to an interesting site that may provide a few facts for this
> discussion:
>
> http://hst-jwst-transition.hq.nasa.gov/hst-jwst/
>
> In particular:
>
> http://hst-jwst-transition.hq.nasa.gov/hst-jwst/panel_docs.htm
>
> Enjoy!
>

FACTS! you must be some kinda Usenet newbie... :-)


--
Reed Snellenberger

[Keith F. Lynch]

Henry Spencer > wrote:
> A private operator is going to want to see revenue from HST
> operations. If you zero out NASA's HST-operations budget, then
> where, exactly, would that revenue come from?

Turn HST over to amateur astronomers, who will operate it for free.
If you exclude the possibility of future Shuttle maintenance missions,
the costs of operating HST consist entirely of labor, which can be
entirely provided by amateur astronomers and amateur radio operators.
--
Keith F. Lynch - - http://keithlynch.net/
I always welcome replies to my e-mail, postings, and web pages, but
unsolicited bulk e-mail (spam) is not acceptable. Please do not send me
HTML, "rich text," or attachments, as all such email is discarded unread.

[G EddieA95]

>payload facing aft for
>> return? That would put the much-heavier main mirror/instrument section
>> well forward of where it was for launch.
>
>I think that MIGHT work. It depends on the magnitude of forces on teh
>mirror in an abort.

Abort? On the way down?

[Greg D. Moore \(Strider\)]

"G EddieA95" > wrote in message
...
> >payload facing aft for
> >> return? That would put the much-heavier main mirror/instrument section
> >> well forward of where it was for launch.
> >
> >I think that MIGHT work. It depends on the magnitude of forces on teh
> >mirror in an abort.
>
> Abort? On the way down?

Sorry, I was typing fast (crying baby in the other room.)

I wasn't clear. I was thinking that the original config (mirror aft) was
probably partly constrained by abort limits. I'm guessing here but I'd
think the mirror would be able to take the launch stresses and possible
abort ones supported from the back.

For a re-entry, since you don't have abort modes like at launch and most of
the force is UP through the bay, not longitudinal, it's less critical to
have the mirror facing the "front."

[Derek Lyons]

"Keith F. Lynch" > wrote:

>Henry Spencer > wrote:
>> A private operator is going to want to see revenue from HST
>> operations. If you zero out NASA's HST-operations budget, then
>> where, exactly, would that revenue come from?
>
>Turn HST over to amateur astronomers, who will operate it for free.
>If you exclude the possibility of future Shuttle maintenance missions,
>the costs of operating HST consist entirely of labor, which can be
>entirely provided by amateur astronomers and amateur radio operators.

Labor, plus consumeables of various types, plus electricity, plus
maintenance on the hardware, plus upkeep on the building...

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

[Jason Rhodes]

"Keith F. Lynch" > wrote in message
...
> Henry Spencer > wrote:
> > A private operator is going to want to see revenue from HST
> > operations. If you zero out NASA's HST-operations budget, then
> > where, exactly, would that revenue come from?
>
> Turn HST over to amateur astronomers, who will operate it for free.
> If you exclude the possibility of future Shuttle maintenance missions,
> the costs of operating HST consist entirely of labor, which can be
> entirely provided by amateur astronomers and amateur radio operators.
> --


I imagine the hundreds of HST-related employees at Goddard Space Flight
Center and the Space Telescope Science Institute will be very surprised to
hear that their jobs could be done for free by amateur astronomers.

Not to mention the fact that your claim that "the costs of operating HST
consist entirely of labor" completely discounts telemetry, computing, and
data storage costs.

Jason

[Henry Spencer]

In article >,
Brian Thorn > wrote:
>>However, there is a problem. Hubble's mass is almost all at its rear. So
>>to put the payload center of mass within the acceptable range, Hubble has
>>to go at the *forward* end of the bay ...
>
>Hubble launched with the aperture facing forward.
>Silly idea... how about loading it in the payload facing aft for
>return? That would put the much-heavier main mirror/instrument section
>well forward of where it was for launch.

Trouble is, I think that puts it *too* far forward. Hubble is heavy
enough that the permissible range of center-of-mass locations is limited;
it may include the center of the cargo bay (for still heavier loads it
doesn't), but it certainly doesn't extend much forward of there.

The fact that Hubble was okay if pointed forward, but only if set as far
forward as possible, suggests that it probably isn't okay the other way
around, even if set as far aft as possible.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Henry Spencer]

In article >,
Keith F. Lynch > wrote:
>Turn HST over to amateur astronomers, who will operate it for free.
>If you exclude the possibility of future Shuttle maintenance missions,
>the costs of operating HST consist entirely of labor, which can be
>entirely provided by amateur astronomers and amateur radio operators.

Most of Hubble's data comes back via TDRS. Its operations would be
severely limited if it had to work directly with a small number of ground
stations, to say nothing of issues of licensing and equipment.

More significant, though, is that Hubble *has* been used by amateur
astronomers, and they turned out to need extensive assistance from
Hubble's professional staff. (It was always expected that they'd need
some, but it was rather worse than expected.) That's why the
Hubble-amateurs program was discontinued after a couple of rounds.

I don't think it would work. The level of effort needed to acquire the
necessary expertise, and then provide it to users on an ongoing basis, is
just too high.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Henry Spencer]

In article >,
Derek Lyons > wrote:
>>Turn HST over to amateur astronomers, who will operate it for free.
>>If you exclude the possibility of future Shuttle maintenance missions,
>>the costs of operating HST consist entirely of labor, which can be
>>entirely provided by amateur astronomers and amateur radio operators.
>
>Labor, plus consumeables of various types, plus electricity, plus
>maintenance on the hardware, plus upkeep on the building...

I think Keith envisioned closing the existing infrastructure entirely,
rather than moving volunteer labor into it. As noted in my previous
posting, I don't think that's practical for something as complex as
Hubble.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Henry Spencer]

In article >,
Jason Rhodes > wrote:
>> Turn HST over to amateur astronomers, who will operate it for free.
>> If you exclude the possibility of future Shuttle maintenance missions,
>> the costs of operating HST consist entirely of labor...
>
>I imagine the hundreds of HST-related employees at Goddard Space Flight
>Center and the Space Telescope Science Institute will be very surprised to
>hear that their jobs could be done for free by amateur astronomers.

It's quite likely that a rather smaller organization could do those jobs,
if it was put together well, especially if you are willing to accept
reduced efficiency. (Part of the reason why Hubble operations are very
labor-intensive is intense pressure to get maximum use out of the thing.)

And it's a rare professional job that is so arcane that you couldn't find
an amateur who could do it, given some investment of time to come up to
speed on the details. The best amateurs are very good indeed; in
astronomy in particular, there is no sharp dividing line between amateurs
and professionals.

The problem is finding enough of those very good people and motivating
them to invest the time and effort. As I noted in another posting, I don't
think the amateur-man-hours pool is anywhere near what would be needed.

>Not to mention the fact that your claim that "the costs of operating HST
>consist entirely of labor" completely discounts telemetry, computing, and
>data storage costs.

It's unlikely that there would be any grievous difficulties with computing
and storage, especially given some relaxation of requirements. As noted
in another posting, communications is a more serious problem.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Derek Lyons]

(Henry Spencer) wrote:
>In article >,
>Derek Lyons > wrote:
>>>Turn HST over to amateur astronomers, who will operate it for free.
>>>If you exclude the possibility of future Shuttle maintenance missions,
>>>the costs of operating HST consist entirely of labor, which can be
>>>entirely provided by amateur astronomers and amateur radio operators.
>>
>>Labor, plus consumeables of various types, plus electricity, plus
>>maintenance on the hardware, plus upkeep on the building...
>
>I think Keith envisioned closing the existing infrastructure entirely,
>rather than moving volunteer labor into it.

Doesn't mean you don't need a place to perform the work from, and such
a place will still need upkeep. (This has been the downfall of many a
model RR club who has bought a building. Failure to set aside money
for taxes, arguments over who cleans the toilet and carries out the
trash, etc...)

>As noted in my previous posting, I don't think that's practical for something
>as complex as Hubble.

Agreed. I was just pointing out the practical difficulties.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

[[email protected]]

Henry Spencer > wrote on Thu, 31 Jul 2003 19:09:22 GMT:
: Brian Thorn > wrote:

>>Hubble launched with the aperture facing forward.
>>Silly idea... how about loading it in the payload facing aft for
>>return? That would put the much-heavier main mirror/instrument section
>>well forward of where it was for launch.

:HS Trouble is, I think that puts it *too* far forward. Hubble is heavy
:HS enough that the permissible range of center-of-mass locations is limited;
:HS it may include the center of the cargo bay (for still heavier loads it
:HS doesn't), but it certainly doesn't extend much forward of there.

The overriding concern I would think is that the mirror support
structure normally works better for loading aimed downward from the
front of the mirror to the back, If the mirror were facing the rear
of the cargo bay, it would have to be supported, "hanging in the
straps" style against the 3G maximum accelleration during launch.
Facing forward, it is pressed down into a support structure that
can freely support the back and sides of the mirror instead of just
the edges of the mirror. While observing, I often have nightmares
of pointing our telescope too far over and having the mirror roll
out of the tube and on down the mountain road....

Jim.

Jim Scotti
Lunar & Planetary Laboratory
University of Arizona
Tucson, AZ 85721 USA http://www.lpl.arizona.edu/~jscotti/

[Scott Hedrick]

"Hallerb" > wrote in message
...

> Heres a EXCELLENT reason to keep hubble around untill at least the Webb
> observatory is operational.
>
> What if Webb is somehow lost?

It's hardly likely that someone would steal the body. He's quite safe.
--
If you have had problems with Illinois Student Assistance Commission (ISAC),
please contact shredder at bellsouth dot net. There may be a class-action
lawsuit
in the works.

[Greg D. Moore \(Strider\)]

"Keith F. Lynch" > wrote in message
...
> Derek Lyons > wrote:
> > Labor, plus consumeables of various types, plus electricity, plus
> > maintenance on the hardware, plus upkeep on the building...
>
> Henry Spencer > wrote:
> > I think Keith envisioned closing the existing infrastructure
> > entirely, rather than moving volunteer labor into it.
>
> Right. Amateurs would operate it from their homes, using their own
> electricity, computer power, radios, etc.
>
> > As noted in my previous posting, I don't think that's practical
> > for something as complex as Hubble.
>
> I disagree. There isn't anything about being *paid* which makes
> someone smarter.

No, but it does give motivation and make freeing up time easier. :-)

I.e. if setting up an observation run takes 8 hours, a paid person considers
that a work day.

A volunteer considers that a long night.

Not that it doesn't happen. Just sometimes harder to find volunteers
willing to do it.


> --
> Keith F. Lynch - - http://keithlynch.net/
> I always welcome replies to my e-mail, postings, and web pages, but
> unsolicited bulk e-mail (spam) is not acceptable. Please do not send me
> HTML, "rich text," or attachments, as all such email is discarded unread.

[Derek Lyons]

"Keith F. Lynch" > wrote:

>Derek Lyons > wrote:
>> Labor, plus consumeables of various types, plus electricity, plus
>> maintenance on the hardware, plus upkeep on the building...
>
>Henry Spencer > wrote:
>> I think Keith envisioned closing the existing infrastructure
>> entirely, rather than moving volunteer labor into it.
>
>Right. Amateurs would operate it from their homes, using their own
>electricity, computer power, radios, etc.

So long as the guy who coordinates things doesn't take sick or go on
vacation. So long as the guy with the radio doesn't die and his wife
locks everyone else out of the house (watched that happen with a
BBS/computer club). So long as the guy whose house the system manuals
are currently out doesn't suffer a fire (as happened to a RR club a
buddy is in)...

Lots of possible pitfalls.

>> As noted in my previous posting, I don't think that's practical
>> for something as complex as Hubble.
>
>I disagree. There isn't anything about being *paid* which makes
>someone smarter.

You may disagree. You may also be ignorant of the complexity of the
system you wish to turn over to volunteers. Historically large
complex systems operated by volunteers have a very hard time locating
and keeping competent volunteers. The very largest resort to dues and
a paid staff to overcome this problem.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

[Kent Betts]

> NOTHING ELSE LOOKS AS GOOD TO THE PUBLIC AS HUBBLE!

The Hubble returns a large amount of useful science. The uh
astronomers who use it want to keep it operating in order to gather
more data.

[Kent Betts]

"Henry Spencer"
> The fact that Hubble was okay if pointed forward, but only if set as far
> forward as possible, suggests that it probably isn't okay the other way
> around, even if set as far aft as possible.

'NASA had originally planned to fetch it with
the space shuttle and put it in the Smithsonian's Air and Space Museum, but that
now seems "exceedingly unlikely," in Dr. Kinney's words.'

The current orbit is good until at least 2013. The Hubble advocates are looking
at two service missions and then a de-orbit mission, say in 2020 or later. If
the second service mission could attach a de-orbit motor, it would save the cost
of developing a space tug. (The unmanned space tug seems to be a natural for
our Russian friends).

NASA says an uncontrolled re-entry is unacceptable, but I would lay better than
even odds that it comes down when it feels like it, which at this point is
shortly after 2013.

[Jonathan Silverlight]

In message >, Kent Betts
> writes
>"Henry Spencer"
>> The fact that Hubble was okay if pointed forward, but only if set as far
>> forward as possible, suggests that it probably isn't okay the other way
>> around, even if set as far aft as possible.
>
>'NASA had originally planned to fetch it with
>the space shuttle and put it in the Smithsonian's Air and Space Museum,
>but that
>now seems "exceedingly unlikely," in Dr. Kinney's words.'

If they did that, who would get the backup ? (which is already there, or
was. They removed some parts for the real thing a few years ago)
--
"Roads in space for rockets to travel....four-dimensional roads, curving with
relativity"
Mail to jsilverlight AT merseia.fsnet.co.uk is welcome.
Or visit Jonathan's Space Site http://www.merseia.fsnet.co.uk

[OM]

On 31 Jul 2003 22:40:24 -0400, "Keith F. Lynch" >
wrote:

>I disagree. There isn't anything about being *paid* which makes
>someone smarter.

....Agreed. In fact, most of the really dumb decisions made by
corporate marketing goons are made by the ones who have degrees that
say they're smarter than the average goon.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[OM]

On Fri, 1 Aug 2003 01:55:58 -0700, "Jason Rhodes"
> wrote:

>It doesn't have anything to do with being smarter. It has to do with having
>the requisite skills. If you have used the Hubble and still feel that a
>bunch of amateurs could run it in their spare time, I stand corrected. if
>you haven't used it, I would guess it is significantly more complex to
>operate and use than you imagine.

....You know, that brings up a good question: just exactly what does
the Hubble OS environment look like? Are we still dealing with DOS
screens, or have they adopted a Wintel or - God/Yahweh/Roddenberry
forbid - a Linux OS with a GUI? Or is it just drop in a quarter and
move the Atari cursor around until it lands on the star you want
imaged?


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[G EddieA95]

>Universities already get most of their astronomy funding from the
>government. If the government decides not to fund Hubble, the above
>scenario seems unlikely (although not impossible).

Alumni associations might in some way fill in the breach.

[G EddieA95]

>2020 or later. If
>the second service mission could attach a de-orbit motor, it would save the
>cost
>of developing a space tug.

Hubble is worthless on the ground and certainly in pieces on the ocean floor.
Could it be boosted into a high "graveyard" orbit? Then should a need arise
for this piece of expensive equipment, it would remain in being and waiting for
reactivation.

[G EddieA95]

> I'm not sure about
>the CG limit, but as you say, it has to be within the abort limit or they
>wouldn't have launched it in the first place.

The cg limit has since changed, due to the presence of the ISS docking airlock
in the forward cargo bay. So what worked when HST launched might not work now.

[Christopher P. Winter]

On 27 Jul 2003 22:04:58 GMT, "Jorge R. Frank" > wrote:

>OM <om@our_blessed_lady_mary_of_the_holy_NASA_research _facility.org>
>wrote in :
>
>> On Sun, 27 Jul 2003 04:45:52 -0500, "Kent Betts"
> wrote:
>>
>>>Instead NASA is studying the possibility that a robotic rocket could
>>>be sent to attach itself to the telescope and ease it out of orbit
>>>safely into the ocean.
>>
>> ...Now *here's* where nobody's thinking over there. If they can launch
>> a de-orbit retro, why can't they simply use it to change the orbital
>> plane and allow a Shuttle to retrieve it *and* still retain ISS
>> capabilities?
>
>A deorbit burn from HST's altitude requires a delta-V of around 150 m/s.
>
>A plane change from HST to ISS requires a minimum delta-V of around 3,000
>m/s.
>

Could an electrodynamic tether system effect the plane change? I doubt
that time would be much of an issue, and it would be an interesting
experiment.

Of course, ISTR that tethers are out of fashion now.

>> Gah.
>
>Gah to you, too.

Can't help but think of James Mowry, restless and pigheaded, habitually
lapsing into Sirian at the end of Eric Frank Russell's _Wasp_.

Chris W.
--
"You really are a Terran, hi?"

"Yar," said Mowry, forgetting himself.

"Yar to you too."

[Hallerb]

>
>>>A deorbit burn from HST's altitude requires a delta-V of around 150
>>>m/s.
>>>
>>>A plane change from HST to ISS requires a minimum delta-V of around
>>>3,000 m/s.

What would it be to park it in a high stable orbit good for at leasst 50 years
or so?

By that time it could be retrieved and be a wonderful display

[Peter Stickney]

In article >,
Christopher P. Winter > writes:
> On 27 Jul 2003 22:04:58 GMT, "Jorge R. Frank" > wrote:
>>Gah to you, too.
>
> Can't help but think of James Mowry, restless and pigheaded, habitually
> lapsing into Sirian at the end of Eric Frank Russell's _Wasp_.

Yar.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Scott Hedrick]

"Hallerb" > wrote in message
...
> By that time it could be retrieved and be a wonderful display

First, grace us with an answer to my question.
--
If you have had problems with Illinois Student Assistance Commission (ISAC),
please contact shredder at bellsouth dot net. There may be a class-action
lawsuit
in the works.

[David Lesher]

(Henry Spencer) writes:


>Unfortunately, the upper end is not *just* barrel, there's a lot of
>equipment and other clutter attached. I doubt the practicality of cutting
>a section off in orbit.

I see two astronauts, on either side, with a BIG bucksaw......
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[LooseChanj]

On or about Sun, 3 Aug 2003 18:51:42 +0000 (UTC), David Lesher
> made the sensational claim that:
> (Henry Spencer) writes:
>>Unfortunately, the upper end is not *just* barrel, there's a lot of
>>equipment and other clutter attached. I doubt the practicality of cutting
>>a section off in orbit.
>
> I see two astronauts, on either side, with a BIG bucksaw......

I'm a crosscut saw baby, drag me across your Hubble...
--
This is a siggy | To E-mail, do note | This space is for rent
It's properly formatted | who you mean to reply-to | Inquire within if you
No person, none, care | and it will reach me | Would like your ad here

[Jorge R. Frank]

(MasterShrink) wrote in
:

>>NASA can avoid the post-flight mod by doing the retrieval mission on
>>an orbiter slated to be retired after the flight anyway (which was the
>>original plan for Columbia after the HST retrieval mission, in 2009 or
>>so).
>
> Yes...but what orbiters are planned to be retired any time soon?
> Discovery, Atlantis and Endeavour are all bound for missions to ISS
> over the next few years and will be busy birds.

Well, yeah... my reasoning was based on this: in the future, at just about
any given time, one of the three birds will be down for maintenance (OMM).
If the plan is to retire the fleet at a given date, odds are that one of
the three will be in OMM on that date. If that's the case, there's no point
in putting it through OMM in the first place, and it could do the Hubble
retrieval mission and retire before the other two.

So if the fleet were to be retired in, say 2012, the Hubble retrieval could
be around 2009 as originally planned. OTOH, a 2020 fleet retirement would
require extending Hubble's life to around 2017.

It seems to be a moot point now since the astronaut office has come out in
opposition to a Hubble retrieval mission.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Hallerb]

>News: Hubble plans and policy

Well the astronauts dont want to retrieve a working observatory and personally
I think the money should be found to keep it operational but heres the latest
story on this....

http://www.nature.com/nsu/030728/030728-13.html

[Sam Seiber]

Hallerb wrote:
> What would it be to park it in a high stable orbit good for at leasst 50 years
> or so?
>
> By that time it could be retrieved and be a wonderful display

I was just looking at Sky & Telescopes web site. In an article there,
NASA doesn't want to leave a problem for the next generation to clean
up. Currently, NASA is making no such plans to keep it in orbit
for a long time.

Sam

http://skyandtelescope.com/news/article_1017_1.asp

[MasterShrink]

>
>It seems to be a moot point now since the astronaut office has come out in
>opposition to a Hubble retrieval mission.
>

Well, on one side I am not a big fan that the astronauts are giving a "tumbs
down" to an HST retrieval mission...

On the other hand, at least they are using the post-STS 107 situation to
reassert some more influence over flight objectives which might be a good
thing.

-A.L.

[Hallerb]

>
>Well, on one side I am not a big fan that the astronauts are giving a "tumbs
>down" to an HST retrieval mission...
>
>On the other hand, at least they are using the post-STS 107 situation to
>reassert some more influence over flight objectives which might be a good

I think its a matter of timing. Retrieve hubble before Webb is working
successfully BAD IDEA!

Service hubble again and retrieve in 8 years FINE IDEA if its job is done.

If Webb fails for any reason and hubble is already deorbted that would be the
worst outcome.

How difficult would it be to bring hubble home, rebuild and relaunch it again?

Have they looked at this option? Yeah I know its costly...

Or fly the hubble spare? Have 2 in orbit?

[Kent Betts]

> "Dale" > wrote
> > >
> > >The professional astronomers are not going to relinquish Hubble as
> > >long as it is functioning.
> >
> > Seems to me far more likely, should they decide to stop supporting
> > Hubble and turn the keys over to somebody, they'd see if a group of
> > universities would choose to get together to use and support it,

> > Dale

The professional astronomers are not going to relinquish Hubble as long as it is
functioning.

[Kent Betts]

Charles Buckley
> wrote:
> > Recovery? That would mean loading a big heavy Hubble into the
> >payload bay of a shuttle and returning it to Earth, correct?

That was the original plan. The Hubble is said to be too dangerous to fall into
the atmosphere at a random location. NASA now considers a manned flight to
return the Hubble as "unlikely". NASA is nattering about an unmanned tug. I
would give five to one odds that it eventually falls to earth unaided and causes
no damage. We won't know until 2013 at the earliest.

[Derek Lyons]

"Kent Betts" > wrote:
>
>The professional astronomers are not going to relinquish Hubble as long as it is
>functioning.
>

The professional astronomers only control Hubble so long as they can
find someone to fund it.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

[Henry Spencer]

In article >,
Jason Rhodes > wrote:
>> > As noted in my previous posting, I don't think that's practical
>> > for something as complex as Hubble.
>> I disagree. There isn't anything about being *paid* which makes
>> someone smarter.
>
>It doesn't have anything to do with being smarter. It has to do with having
>the requisite skills.

And above all, with having the requisite *time*, to acquire and maintain
those skills and apply them effectively in ways that actually yield results.

There are a number of things I would love to do, and which I do have the
necessary skills for, which just aren't going to happen unless somebody
pays me to do them... because there simply aren't enough hours in the day,
and I have to set priorities.

Furthermore, there are an assortment of skills I'd like to acquire and
undoubtedly could acquire, which (on present plans) I'm not going to
acquire, for the same reason.

We're not talking about something a handful of random guys, even smart
ones, could do in their spare moments. It's marginally possible that a
small group of exactly the right guys might be able to pull it off if they
had 9-5 jobs and devoted every remaining waking minute to it. Good luck
getting that level of time commitment from those guys, especially over a
long period of time.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

[Dale]

On Sun, 17 Aug 2003 20:43:17 -0700, "Jason Rhodes" > wrote:

>Neither of the quoted messages were written by me.

You may have just won a t-shirt :)

Dale

[Brad Guth]

Here is another means to an end (actually several means), including
the salvage of Hubble along with the task of getting ourselves to/from
and of surviving places like Venus L2 and even Mars.

Lunar/Moon Space Elevator, plus another ISS situated within the CM

Lunar Space Elevator Linear Tether Considerations (CM @1^9 kg):
363,300 km, ME-L1 = 58,128 km, L1.1 = 63,941 km (-1738 km = 62,203 km)
405,500 km, ME-L1 = 64,880 km, L1.1 = 71,368 km (-1738 km = 69,630 km)

Not that I'm telling anyone what they shouldn't already know, such as
about dealing with space radiation is where I've learned from others
(including NASA) of what to expect at Earth L2, within the Van Allen
zone and of a couple of altitudes below or in between the Van Allen
zone and the surface of Earth. What's oddly missing is any concise
definition of what Earth L4/L5 have to offer and thereby of what the
lunar surface is like. Even clear information of what's to be expected
at ES-L1 seems to have become a secret because, of what there is to be
found simply doesn't compute for what those Apollo missions endured by
any long shot.

Of course, if you have something measured and/or calculated of Earth
L4/L5, for the solar maximum year and/or for the solar minimum year,
that's exactly what we all need to learn about, so that others or at
least that I can estimate what to expect at Venus L2, where I believe
the space environment of VL2 or VE-L2 is worth knowing, since even a
robotic mission such as a TRACE-II would need to be designed for the
radiation environment, as it's highly unlikely that the sun is going
to represent a purely UV-->IR source of energy, such as during those
extremely lucky Apollo missions and, even though the VL2 position is
roughly 90% shaded by Venus itself, there's still a good deal of solar
influx/weather that'll represent a whole lot more Sv dosage than any
human expedition can tolerate within the existing ISS shield
capabilities, especially if that's having to be based upon a 2 year
mission.

This radiation tit for tat is where the idea of affordably obtaining
tonnes of that nifty clumping moon dirt comes in real handy. Since we
can launch a manned mission, if need be in stages and assembled
somewhat like ISS. The only stumbling block is the issue of our having
to launch sufficient mass that'll surround the likes of yourself with
good enough density that'll effectively shield those onboard from the
worst the sun has to offer, not to mention whatever the galaxy has to
offer. Unfortunately, besides the rather enormous cost per tonne
delivered, the side effect of launching that amount of mass is the
resulting deposit of artificially created CO2 for the rest of us back
here on Earth, where this being from what I've learned that the
overall process of creating such mass and of having to launch along
with sufficient energy for a interplanetary mission could represent a
100 fold creation of CO2, which is a darn good thing if it were for a
planet like Mars that may need to be warmed up and simply didn't care
about further CO2 pollution but, for Earth that another confirmed "no
no".

Since I've found some references to the EL5 environment in need of as
much as 1000 g/cm2 and, I've located information upon the Earth L2
environment and of what certain densities of shielding accomplish, as
such I've interpreted and/or extrapolated upon what the EL5 radiation
environment must be. Again, if there were a concise set of radiation
tables and of sources other than just the cold-war NASA moderated
verity, then I'd not have had to bother the wizardly likes of
http://clavius.org which no matters what can't stray from their
pretentious cold-war outcome of those Apollo missions.

As another means to an end, for the prospect of accommodating a depot
of moon dirt situated in a nearly Zero-G environment seemed too good
to pass up. The idea of constructing a lunar based space elevator even
seems entirely possible, especially if the likes of those claiming any
Earth based (EM-L1) space elevator should be accomplish, as there's no
freaking contest in the fact that a lunar based elevator will become a
whole lot simpler and, that it could be accomplished within the
current level of expertise and by way of existing materials
application technology. The idea of having another ISS configured
within the massive lunar space elevator CM depot is yet another win
win for all sorts of things.

I've proposed a number of my village idiot ideas and benefits
associated with having a moon-dirt depot situated at ME-L1.1 (LL1.1),
and as usual, all I've gotten in return is either their black-hole
voids of nothingness or loads of sanctimonious flak instead of other
ideas or specific numbers, as God forbid, should some of our crack
space wizards actually stipulate upon anything specific that might end
their career that was probably phony to begin with. The following page
is simply an ongoing build, receiving corrections as well as whatever
feedback that can be put to the test (your input is welcome);
http://guthvenus.tripod.com/moon-L1-elevator.htm

If you don't know what works but otherwise seem to know for a fact
what doesn't work, then that's the sort of information we need, as
either way this moon space elevator is a doable thing, especially as
compared to accomplishing any Earth based space elevator and/or of our
going to/from any frozen and irradiated to death planet such as Mars.

BTW; I'm all for saving the butts of those Hubble huggers (I'd even
pay or it out of my own pocket), though if only I could think of
something morally worthy for such a fine instrument and of supposedly
such qualified souls to be focused upon, such as a nighttime side of a
certain planet that just might be capable of artificially illuminating
portions of their otherwise pitch black though sufficiently
transparent nighttime clouds. But gee whiz folks, I guess I can't
think of a single god damn worthy thing for that otherwise
horrifically spendy instrument that'll soon make for another terrific
display as it burns itself up upon reentry (I guess it'll be good
riddance to a source of such terrific images of places humans will
never obtain an ounce nor a gram of worth in a thousand generations).

Regards, Brad Guth / IEIS discovery of LIFE on Venus
http://guthvenus.tripod.com

[Henry Spencer]

In article >,
Christopher P. Winter > wrote:
>>A plane change from HST to ISS requires a minimum delta-V of around 3,000
>>m/s.
>
> Could an electrodynamic tether system effect the plane change? I doubt
>that time would be much of an issue, and it would be an interesting
>experiment.

Unfortunately, if it is an experiment, NASA must plan for the possibility
that it would fail. So you don't really gain a lot that way.

And as others have noted, electrodynamic tethers are not well suited to
doing large plane changes. It's not *impossible* to use them for that,
but it's not simple or easy.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |