Panel Identifies Three Options For Space Telescope Transition

Donald Savage
Headquarters, Washington August 14, 2003
(Phone: 202/358-1547)

RELEASE: 03-264

PANEL IDENTIFIES THREE OPTIONS FOR SPACE TELESCOPE TRANSITION

An independent panel of astronomers identified three
options for NASA to consider for planning the transition from
the Hubble Space Telescope (HST) to the James Webb Space
Telescope (JWST) at the start of the next decade.

The panel, chaired by Prof. John Bahcall, Institute for
Advanced Study, Princeton, N.J. chartered by NASA earlier
this year, submitted their report to the agency this week.

NASA's current plans are to extend the life of the HST to
2010 with one Space Shuttle servicing mission (SM 4) in 2005
or 2006. The plan is tentative pending the agency's return to
flight process and the availability of Shuttle missions. NASA
plans to eventually remove the HST from orbit and safely
bring it down into the Pacific Ocean.

"NASA is deeply appreciative to Prof. Bahcall and the panel
for getting this thoughtful report to us ahead of schedule,"
said Dr. Ed Weiler, NASA's Associate Administrator for Space
Science. "We have a big job to do to study the panel's
findings and consider our options, and we will respond as
soon as we have time to evaluate their report," Weiler said.

The three options presented by the HST-JWST Transition Plan
Review Panel, listed in order of priority, a

"1. Two additional Shuttle servicing missions, SM4 in about
2005 and SM5 in about 2010, in order to maximize the
scientific productivity of the Hubble Space Telescope. The
extended HST science program resulting from SM5 would only
occur if the HST science was successful in a peer-reviewed
competition with other new space astrophysics proposals."

"2. One Shuttle servicing mission, SM4, before the end of
2006, which would include replacement of HST gyros and
installing improved instruments. In this scenario, the HST
could be de-orbited, after science operations are no longer
possible, by a propulsion device installed on the HST during
SM4 or by an autonomous robotic system."

"3. If no Shuttle servicing missions are available, a robotic
mission to install a propulsion module to bring the HST down
in a controlled descent when science is no longer possible."

In addition, the panel described various ways to ensure
maximum science return from the HST if none, one or two
Shuttle servicing missions are available.

"A lot of astronomers and NASA officials were astonished,
when we said our report was ready just one week after our
public meeting. This was possible because we reached
unanimous agreement on our conclusions very quickly;
remarkable when you consider there were six independent-
minded scientists on the panel. Our secret is we did our
homework very thoroughly. Many people helped to educate us,"
Bahcall said.

For information about NASA and space science on the Internet,
visit:

http://www.nasa.gov

The HST-JWST Transition Panel report is available on the
Internet at:

http://www.nasa.gov/audience/formedi...MP_Public_Repo
rts.html

Information about the panel, including membership and
charter, is available at:

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

For information about the Hubble Space Telescope on the
Internet, visit:

http://oposite.stsci.edu/

For information about the James Webb Space Telescope on the
Internet, visit:

http://ngst.gsfc.nasa.gov/


-end-

Why are they removing the shuttle?

Your question made me re-read the original post several times... I didnt see
any referrence to removing the shuttle, but the eventual removal of the
hst...
Joe

"jojo" wrote in message
...
Why are they removing the shuttle?

NASA is never going to launch a robotic vehicle to de-orbit HST. These cats are
pulling our leg.

EIther a rocket is attached during a service mission or it is just going to come
down unguided. It is not economical to launch any sort of de-orbit mission. It
will come down in the ocean or knock down some rubber tree, and NASA will say
"That's nice. We would have been happy to spend the billion dollars for a
controlled return, but blah blah."

Come to think of it, if NASA *does* try to do a de-orbit mission, there should
be a congressional investigation.

by a propulsion device installed on the HST during
SM4 or by an autonomous robotic system."

"3. If no Shuttle servicing missions are available, a robotic
mission to install a propulsion module to bring the HST down

The most likely scenario is that Servicing Mission 5 will carry some
sort of attitude control unit that also incorporates an end-of-life
de-orbit capability, so that Hubble can be used beyond its nominal
lifetime, but still have a controlled de-orbit capability.

What I am wondering is how Congress/CAIB will allow Shuttle to fly to
Hubble, given that a major malfunction, such as what happened with
STS-107, would prove fatal to the Shuttle crew (unlike ISS missions,
there is no place to stay at Hubble. I would imagine that this would
lead to a requirement to have a 2nd Shuttle on short term standby at
the Cape, ready to launch if there is a tile/leading edge panel
problem with the 1st shuttle, but this seems like something out of
Armageddon.

(Explorer8939) wrote in
om:

What I am wondering is how Congress/CAIB will allow Shuttle to fly to
Hubble, given that a major malfunction, such as what happened with
STS-107, would prove fatal to the Shuttle crew...

The CAIB will not only allow it, their recommendations anticipate it:

http://www.caib.us/news/press_releases/pr030627.html

excerpt
Before return to flight, for non-station missions, develop a comprehensive
autonomous (independent of station) inspection and repair capability to
cover the widest practicable range of damage scenarios.
/excerpt

The inclusion of a paragraph for non-station missions clearly shows that
the CAIB expects non-station missions to resume. NASA's chosen
inspection/repair strategy (a 58' boom attached to the RMS) will
accommodate this.

(unlike ISS missions,
there is no place to stay at Hubble.

Reality check: The US flew shuttles from 1981 to 2000 with "no place to
stay", and previous spacecraft (Mercury, Gemini, Apollo) likewise flew with
"no place to stay" with the brief exception of Skylab (1973-74). Making "a
place to stay" a requirement means that the US would be forever limited to
spaceflights at 51.6 degree inclination, 210 nmi altitude. I agree with you
that I could see Congress imposing just such a restriction, but I believe
it would be a craven and cowardly move. I would gladly volunteer for a
Hubble mission.

I would imagine that this would
lead to a requirement to have a 2nd Shuttle on short term standby at
the Cape, ready to launch if there is a tile/leading edge panel
problem with the 1st shuttle, but this seems like something out of
Armageddon.

Considering that the fleet is down to three orbiters, with one of the three
down for maintenance a majority of the time, there is no way this condition
can be satisfied. You can launch shuttle A with shuttle B standing by on
the pad (and C down for maintenance), but then you can't launch B until A
has landed and been reprocessed. It is highly unlikely that the CAIB would
issue such a far-fetched recommendation, but it is just the kind of fine
thinking I'd expect from Congress.

--
JRF

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