Death Sentence for the Hubble?

Rodney Kelp wrote:
...the NGST will be many times better.

NGST = Next Generation Space Telescope.
In 2002 it was renamed to James Webb
Space Telescope (JWST).

It is a monolithic design not suitable
for repair or upgrade. If something goes
wrong it will become another piece of
space junk.

All satellites and space telescopes should
be modular and compatible with telerobots
so that they can be upgraded frequently
and repaired.

Max Beerbohm ) wrote:
: JATO jato wrote:
: On 12 Feb 2005 20:45:16 -0800, "MrPepper11" wrote:
:
:
: New York Times
: February 13, 2005
:
: EDITORIAL
: Death Sentence for the Hubble?
:
:
:
:
: bla bla bla..
:
: -JATO
: http://jatobservatory.org

: Notice no discussion of the risks.

: "Our heroic cosmanauts must undertand that the State demand sacrifices..."

: Sorry, about that - wrong station.

: Seriously, if you are going to say that there is no reason not to do a
: Hubble visit, you need to address the safety issue - as some on this
: group have done.

If we can't go to the Hubble, then how are we expectd to go back to the
moon and onto Mars?

: The article above is poorly researched because of this.

Yes, he forgot to mention pure political motivation of it all, rather than
hinting at it and dancing around it.

Eric

Charles Buckley ) wrote:
: David M. Palmer wrote:
: In article , Max Beerbohm
: wrote:
:
:
:
: Seriously, if you are going to say that there is no reason not to do a
: Hubble visit, you need to address the safety issue - as some on this
: group have done.
:
: The article above is poorly researched because of this.
:
:
: The expected risk cost is ~0.1 lives and 0.015 shuttles (assuming a
: 1/70 chance of disaster with each shuttle mission not to ISS).
:

: Recalculate for 1/50 That is the current safety rating.


: It's not a safety issue. It is quite a bit of a project management
: issue. The 2007 launch to Hubble would be right in the middle of
: ISS flights. They would have to take a shuttle offline and do
: a one-off flight to another destination. If they go with a
: safety net of a spare shuttle, then you have created a gap of
: a couple months when ISS construction and processing is interrupted.

So ISS will get completed two months early and THAT is why Hubble can't
be serviced? Two months? Real leadership would complete ISS and fix the
Hubble. Partisan BS has Texas getting its project done whereas the ongoing
Maryland project can go to hell!

: It's also a 40% chance of vehicle loss over the remaining number of
: flights, to where no one individual flight is more risky than any
: other, it is the aggregate total that is the issue. Without ISS,
: shuttle would be permamently grounded already. There is zero push
: to get it back into service for anything else.

No, fix Hubble and then consider grounding the shuttle if you think ISS
isn't worth it. We KNOW that Hubble has value!

: The deaths are equivalent to ~12 million passenger miles of automotive
: travel, or every member of the American Astronomical Society driving
: 2000 miles, or every U.S. amateur astronomer driving about a dozen
: miles, or every person who has ever looked at a Hubble picture and
: thought 'wow! that's cool' driving a few hundred meters.
:
: Or to put it another way, it's equivalent to each of the seven
: astronauts who decide that they are willing to risk a Shuttle flight to
: fix Hubble doing so.
:
: Now that the safety issue has been addressed (although not compared to
: that of the dozens of planned trips to the ISS, with only a marginal
: increase in safety per flight) let's go and fix it.
:

In article ,
Andrew Nowicki writes:
All satellites and space telescopes should
be modular and compatible with telerobots
so that they can be upgraded frequently
and repaired.

Umm, how did you reach that conclusion? I thought the HST experience
shows the opposite. How many "new Hubbles" could have been launched
for the price of the servicing capability?

Just to be clear: this comment refers to future missions, not what
should be done with the existing HST.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

If they don't make the NGST better, higher quality, and more capable what's
the point? Is there no progress any more?

"Henry Spencer" wrote in message
...
In article ,
Rodney Kelp wrote:
That's ok, the NGST will be many times better.

For some applications, not for all of them. (No UV capability in
particular.)

And that assumes that NGST actually flies.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

Andrew Nowicki wrote:
All satellites and space telescopes should
be modular and compatible with telerobots
so that they can be upgraded frequently
and repaired.

If we require compatability with non-existent entities
then we might as well require that the device work by
magic, or be compatable with leprechaun-based maintenance
work or what-have-you. Besides which, maintenance
compatability does not come cheap, nor does the maintenance,
with or without robots. Realistically, you save very
little, if anything, from maintenance compatability.
Indeed, sometimes you lose because you spend money fixing
up obsolete hardware rather than putting the effort into
completely new systems. For the money we've spent on
HST upgrades already we could have had another HST-class
telescope on orbit *right now* (maybe more than one), and
it wouldn't be 15 years old with bits that use 20+ year old
technology.

In article ,
Rodney Kelp wrote:
That's ok, the NGST will be many times better.
For some applications, not for all of them. (No UV capability...

If they don't make the NGST better, higher quality, and more capable what's
the point? Is there no progress any more?

There was a decision, very early in the design process of NGST/JWST, that
all the interesting/fun astronomy was going to be happening in the IR, and
so there was no need for UV and little need for visible wavelengths.

This does have design implications: the longer wavelengths mean more
relaxed optical requirements, easier to meet with deployable mirrors and
such. (This is also why adaptive-optics systems on Earth-based telescopes
mostly work in the IR at present.) In other words, if you're willing to
build a telescope that's IR-only, you can make it rather bigger with the
same technology... and that means more light-gathering power and better
ability to study very faint, very distant objects.

So, it wasn't a grossly unreasonable tradeoff; it had important virtues.
It may have been the wrong decision but it wasn't stupid.

But there *are* astronomers who do think it was the wrong decision.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

Rodney Kelp wrote:
If they don't make the NGST better, higher quality, and more capable what's
the point? Is there no progress any more?

It will almost certainly be better, just not in the same areas
where HST currently operates.

Jorge R. Frank wrote:
Charles Buckley wrote in
:


David M. Palmer wrote:

In article , Max Beerbohm
wrote:




Seriously, if you are going to say that there is no reason not to do a
Hubble visit, you need to address the safety issue - as some on this
group have done.

The article above is poorly researched because of this.


The expected risk cost is ~0.1 lives and 0.015 shuttles (assuming a
1/70 chance of disaster with each shuttle mission not to ISS).


Recalculate for 1/50 That is the current safety rating.


According to whom? Cite your sources, please.


Demonstrated safety. They have not yet established that they can
calculate the the safety rate accurately.


At *worst*, it's 1/56.5 (+ post-CAIB safety improvements).

*Reasonably*, it's 1/88, (+ post-CAIB safety improvements).

Again, *cite* your sources, if you have any.

Eric Chomko wrote:
Charles Buckley ) wrote:
: David M. Palmer wrote:
: In article , Max Beerbohm
: wrote:
:
:
:
: Seriously, if you are going to say that there is no reason not to do a
: Hubble visit, you need to address the safety issue - as some on this
: group have done.
:
: The article above is poorly researched because of this.
:
:
: The expected risk cost is ~0.1 lives and 0.015 shuttles (assuming a
: 1/70 chance of disaster with each shuttle mission not to ISS).
:

: Recalculate for 1/50 That is the current safety rating.


: It's not a safety issue. It is quite a bit of a project management
: issue. The 2007 launch to Hubble would be right in the middle of
: ISS flights. They would have to take a shuttle offline and do
: a one-off flight to another destination. If they go with a
: safety net of a spare shuttle, then you have created a gap of
: a couple months when ISS construction and processing is interrupted.

So ISS will get completed two months early and THAT is why Hubble can't
be serviced? Two months? Real leadership would complete ISS and fix the
Hubble. Partisan BS has Texas getting its project done whereas the ongoing
Maryland project can go to hell!


Generally, sudden halts in construction projects are bad. They can
sometimes allow things backlogged to catch up, but that is not the case
here. They have the parts and are ready to roll. Arbitrarily stopping
construction to do a sideline task in a life extension program on
something that has already been extended is not really something that
makes a large amount of sense, or even a small amount. Shuttle is there
for ISS now. Nothing else.