Hubble Status Report - November 2004

29 Nov 2004 14:11

The Hubble spacecraft is operating nominally, with the exception of the
Space Telescope Imaging Spectrograph (STIS), one of the five on-board
science instruments, which failed on 3 August 2004. The Failure Review Board
concluded that the failure was due to the 5V power supply for the mechanism
electronics.
An additional 45 proposals have been called in to maintain the high
observing efficiency of the telescope. These proposals had already been
rank-ordered by the original Cycle 13 Time Allocation Committee. A number of
already approved programs that originally used STIS are in the process of
being converted to use other instrument modes, most notably the Solar-Blind
Channel (SBC) of the Advanced Camera for Surveys (ACS).
In the event that HST has to be operated with only two gyros before a
refurbishment can take place, preparations and development for the Two-Gyro
Science Mode continue. Detailed simulations show that the impact on image
quality from jitter is substantially less than originally assumed, so that a
"voluntary" entry into Two-Gyro Mode is now being discussed in order to
preserve the lifetime of the currently operating four gyros. On-orbit tests
are planned for November of this year.
The Cycle 14 Call for Proposals will be issued in mid-October, with a
deadline for the submission of Phase I information by late January 2005.
This call includes the policy modifications to accommodate operation in
Two-Gyro Mode.
On 9 August 2004, the NASA Administrator gave the go-ahead for proceeding
with a robotic servicing mission for HST. This robotic servicing mission is
planned to include: installing de-orbit hardware, extending HST observing
life (batteries and gyros), and installing two new science instruments.
These developments now point to a servicing mission to HST in late 2007 or
early 2008.
New versions of the data reduction and archive retrieval software were
installed in September. This installation brings many system improvements
and fixes, and also provides significant new functionality by the first
pre-archive and retrieval application of MultiDrizzle to ACS data sets.
MultiDrizzle allows the combination of associated ACS images into one image,
while simultaneously removing cosmic ray hits.
On 23 September 2004, scientists presented recent results based on the
Hubble Ultra Deep Field (HUDF) to the astronomical community and the media.
Detailed analyses of this deepest optical view of the universe by several
expert teams have at last identified what may turn out to be some of the
earliest star-forming galaxies. Astronomers are now debating whether the
hottest stars in these early galaxies may have provided enough radiation to
"lift a curtain" of cold, primordial hydrogen that cooled after the big
bang. This is a problem that has perplexed astronomers over the past decade,
and the Hubble Space Telescope has at last glimpsed what could be the ihend
of the opening actli of galaxy formation. These faint sources illustrate how
astronomers can begin to explore when the first galaxies formed and what
their properties might be. But even though HST has looked 95 percent of the
way back to the beginning of time, astronomers agree that's not far enough.

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Jacques :-)

www.spacepatches.info