NASA Urged to Reconsider Hubble Decision

"Brian Thorn" wrote in message ...
On Fri, 30 Jan 2004 18:23:27 GMT, "Jason Rhodes"
wrote:

What makes Hubble different is that it is the most successful scientific
instrument in the history of the world.

That is very much debatable. In astronomy alone, Hale and Mt. Wilson
give it a run for its money.


There's this German astronomer on TV over here who makes the point
that the biggest influence the really large and expensive telescopes
have is their taking the economic pressure off the smaller, cheaper
ones. That should give astronomers more time to concentrate on their
research rather than on fighting for time slots and funding.

So in his opinion the greatest contribution of telescopes like Hubble
is a trickle-down effect that smaller projects eventually profit from
that aren't even directly connected with Hubble...


(He's also very much for setting up telescopes on the Lunar far side.)



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Invid Fan wrote:

So I'm glad you're willing to risk theirs When the new Smithsonian
museum opened it was mentioned that Hubble wouldn't be brought back
down, as iirc the shuttle has never landed with that much weight in it
and it just wasn't worth the risk.

This claim doesn't stand up to scrutiny. It's been waved about these parts
on a regular basis of late, and it's time to debunk it.

According to Jenkins' Space Shuttle, 3rd ed., the landing weight of STS-31R
- Hubble's deployment mission - was 189,118 lbs, and the payload (including
Hubble and some smaller bits and pieces) was 25,517 lbs. According to
http://hubble.nasa.gov/faq.html, Hubble weighs about 24,000 lbs on orbit
now, but I'll go the higher figure. So in the STS-31R configuration, we
would be looking at a potential landing weight of 214,635 lbs.

According to Jenkins' book, during the first 100 flights there were *forty*
missions with landing weights over that! A few had landing weights over
230,000 lbs. So it appears that landing weight isn't the great problem it's
made out to be.

I'd like to bring it down, but I
have an image of it not tied down enough in the cargo bay and shifting
at the wrong time...

Not to worry, the weight isn't an issue, and Hubble would be secured with
the same payload bay attachments it was launched with.

--Chris

On Fri, 30 Jan 2004, Invid Fan wrote:

In article , Rand Simberg
wrote:

On Thu, 29 Jan 2004 17:05:58 -0600, in a place far, far away, Brian
Thorn made the phosphor on my monitor glow in such
a way as to indicate that:

On Thu, 29 Jan 2004 11:53:32 -0500, Mark Lopa wrote:

I agree with another post...I astronauts would jump at the opportuity to
not only fly a
mission to service the HST, but to also bring it home.

The astronaut corps evidently has already weighed-in against a Hubble
Retrieval Mission. I'm sure they'd agree to fly SM-4, but they clearly
are against risking their lives just to bring home a trophy for the
Smithsonian.

Then I'd say we need some new astronauts. They've certainly risked
their lives for lesser causes, and I'd risk my life just to go into
space.

So I'm glad you're willing to risk theirs When the new Smithsonian
museum opened it was mentioned that Hubble wouldn't be brought back
down, as iirc the shuttle has never landed with that much weight in it
and it just wasn't worth the risk. I'd like to bring it down, but I
have an image of it not tied down enough in the cargo bay and shifting
at the wrong time...

It's not the weight, it's the center of gravity (CG) that's a concern.
Many shuttle missions have landed with weights comparable to, or greater
than HSTs, but had a different weight distribution so that the CG would
not be too far foward and stress out the foward landing gear or something
like that.
-Mike

Mike Dicenso wrote:

It's not the weight, it's the center of gravity (CG) that's a concern.
Many shuttle missions have landed with weights comparable to, or greater
than HSTs, but had a different weight distribution so that the CG would
not be too far foward and stress out the foward landing gear or something
like that.

Handling in flight is a bigger concern than on the runway. Still, the
shuttle was certified to launch with Hubble, and that certification meant
that the shuttle was permitted to perform a reentry with the payload still
on board. If the mass distribution of Hubble hasn't changed much since it
was deployed, then it shouldn't be a major issue.

--Chris

"Jason Rhodes" wrote in
om:


"Mark Lopa" wrote in message
...
Plus, it would be a real shame not to get this into the Smithsonian.
I
think everyone just
assumed this would happen. But would that have to be an entire
mission
itself...just to bring
it back?

I agree with another post...I astronauts would jump at the opportuity
to
not only fly a
mission to service the HST, but to also bring it home. If I wold hate
to
see it just die and
burn up, I can't image how folks in the organization feel.

Mark


The astronauts (via Grunsfeld) I believe said they would service the
HST but did not want to bring it back. They told this to the Bahcall
committee last year that was exploring the future of HST.

More or less correct. The exact quotes are he

http://hst-jwst-transition.hq.nasa.g..._HST-JWST1.pdf

If astronauts are going to risk their lives to service the Hubble Space
Telescope, we should do it in order to enable great science. For the
upcoming SM4 mission the Astronaut Office has signed up for and is excited
about the prospects of sending a team up to Hubble to install the Cosmic
Origins Spectrograph, the Wide Field-3 Camera, and replace the gyros,
batteries, and install the Aft-shroud Cooling System. The Space Shuttle
Program is aggressively working towards improving the safety of the Shuttle
system and to provide solutions to the tile issues, brought to light by the
Columbia accident, which will enable an SM4 mission to the Hubble.

If there were to be a mission after the SM4 for the purpose of returning
Hubble to earth in the Shuttle Payload bay, the Astronaut Office would have
reservations supporting the mission. Initial analysis shows that perhaps
four spacewalks are required, significant hardware would have to be
jettisoned, and a heavyweight return through the atmosphere would have to
be performed. In a sense this mission would be risking human lives, and a
unique national resource (the Space Shuttle), for the purpose of disabling
great science, albeit due to necessity at end-of-life. For this reason the
Astronaut Office favors the alternate approaches being investigated by the
Office of Space Science, including an autonomously installed propulsion
module mission, or a Shuttle based combined servicing/propulsion module
installation mission.

As astronauts we place our trust in the astronomical community, the NASA
Office of Space Science, and the Office of Space Flight to examine the end-
of-life options for the Hubble Space Telescope. And if it is determined
that the science case drives an additional Hubble servicing mission, the
astronauts will be there to help enable the scientific exploration of the
Cosmos.





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Chris Bennetts wrote in
:

Bruce Sterling Woodcock wrote:

Unless we lose another orbiter and 7 astronauts because
we couldn't inspect and repair tile damage on-orbit
without an ISS visit.

Or unless we spend potentially $1B dollars to specifically
design and implement a non-ISS on-orbit inspection,
repair, and potential rescue scheme, which would only
be used ONCE. To keep the HST operating for 4-10
more years at a cost of $250M/year.

What is your proposed inspection/repair system in case of an ATO abort
on a station mission? You can't make it to the station, and you may
have catastrophic TPS damage. What do you do?

ISTM that a standalone tile-repair solution is required *even for
station missions*.

Not quite. If that were the case, standalone capability would be required
prior to RTF, and there would have been no need for the CAIB to distinguish
them. The CAIB recommendation was that a standalone repair capability be in
place prior to the first non-ISS flight. Their *intent* was that such
capability also be available for subsequent ISS flights that, for whatever
reason, could not reach ISS. We are now seeing the cascading effects of the
law of *unintended* consequences, as applied to that recommendation.

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Chris Bennetts wrote in
:

Hallerb wrote:

Ahh they should service it once more while keeping a backup shuttle
on the pad prepped for launch. Then send the backup to ISS after the
hubble service mission is back safe and sound.

Well, that would eliminate the perceived "schedule pressure" on NASA
to finish the station that seems to be felt around these parts.

No, it wouldn't have. It would have been a processing nightmare, unless it
were performed during the (rare) periods with all three orbiters
available. The schedule pressure to get the mission off in the window
before the next orbiter goes into OMM would have been immense.

Heck, why bother finishing the station if it's going to be ditched in
the Pacific a few years after completion? What's the point?

Why do you think that? The proposal is that the US would withdraw from ISS
around 2016. There is *no* requirement to ditch it in the Pacific at that
point - that would be up to the remaining international partners. They
could continue to operate it as long as they could afford to. Besides, the
US doesn't even have the *capability* to deorbit ISS - *only* the Russians
(and once ATV is available, ESA) can do that. The US does not have the
technical capability to deorbit ISS.

heck a final shuttle flight might be retrieving hubble. it could take
something else up, send it on its way then go pick up hubble and
bring it home.

They did that for the LDEF retrieval. The only issue is that there's
nothing suitable to be launched. A couple of Starshines in gascans?

I don't think HST leaves enough clearance in the payload bay for that,
unless the gascans themselves are also jettisoned.

A mission like this would be a BIG PR splash. Better than destroying
hubble.

Hallerb once again reveals his true colors: PR over safety. He is both an
imbecile *and* a hypocrite.

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Invid Fan wrote in
:

When the new Smithsonian
museum opened it was mentioned that Hubble wouldn't be brought back
down, as iirc the shuttle has never landed with that much weight in it
and it just wasn't worth the risk.

Incorrect. HST was carried *up* in a shuttle, and the payload upmass is
*always* within landing limits, in the event an engine failure during
ascent forces an abort landing with the payload still in the bay.

HST's size (read *volume*) is deceiving. The telescope tube is mostly empty
space; HST's *mass* (11,000 kg) is *far* lighter than many other payloads
that have flown in the shuttle. It's less than half the mass of Chandra/IUS
from STS-93, for example.

I'd like to bring it down, but I
have an image of it not tied down enough in the cargo bay and shifting
at the wrong time...

Why would you think that? Once again, HST was carried *up* in a shuttle,
and ascent loads are worse than entry loads. HST still has the trunnion
pins used to secure it in the payload bay for ascent; *why* do you think it
would need to be "tied down" for entry?

--
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This would be in violation of CAIB recommendations, which say they
must have stand-alone repair capability.

Are you now urging NASA to ignore outside safety advice. Quite a
departure for you, Bob.

Brian



Juast what will happen to a shuttle going to ISS that cant for whatever reason
get to station?

A extra shuttle should be ready to go for EVERY future shuttle flight.

So stand alon repair capability is still needed.

Frankly I dont beliecve we should return to flight till a fast supplies parts
ship to orbit is ready.

Not only would it be useful for a stranded shuttle but ISS as well.

Imagine loosing ISS because of the lack of a $100 part. Crew evacuated and
another problem comes up station tumbles and is lost.

Boy will nasa look stupid.

Putting a shuttle into orbit merely to catch it for mounting at the
Smithsonian is a waste,
and dragging it into the payload bay would be a pretty hairy operation.
Keeping the telescope
in service seems more sensible with a pretty good payback.


I say do the next service mission as planned. Then if its to be deorbited
before the shuttles quit flying uase a shuttle to launch a new whatever then go
pick up hbble and bring it home.