By D. Leckrone, NASA GSFC,

0n September 28, NASA formally announced the selection of the four
astronauts who will conduct the five EVAs currently planned for the next
HST servicing mission, STS-109. This is a very strong group, well up to
the challenges posed by Servicing Mission 3B. The crew is led by Hubble
servicing veteran (and high-energy astrophysicist) John Grunsfeld. John
has flown on three previous shuttle flights. In December 1999, he
performed two spacewalks to service Hubble during servicing mission 3A
(STS-103). In practice runs in the Neutral Buoyancy Laboratory at Johnson
Space Center in Houston, John has developed the techniques for changing
out Hubble’s Power Control Unit (PCU). His work has given us high
confidence that this challenging maintenance task can be carried out
safely and successfully in less than one EVA. We’re feeling a lot better
about it!

Joining John Grunsfeld are two other veteran astronauts, Jim Newman and
Richard Linnehan, and one rookie, Mike Massimino. Newman, whose Ph.D. is
in Physics, has flown on three shuttle missions since 1993. In 1998 he
performed three spacewalks on the first International Spacestation assembly
mission. Interestingly, Linnehan’s background is as a veterinary surgeon
and his previous two shuttle flights have focussed on Life Sciences
experiments. It is said that, when Richard was first contacted about his
selection for the next Hubble repair mission, he was in Southeast Asia
attaching prosthetic limbs to elephants whose legs had been blown off
by land mines! Clearly he brings a lot of experience to our mission in
applying fine manual dexterity to large, bulky objects — perfect for
HST servicing!! Although STS-109 will be Mike Massimino’s first shuttle
flight, he has proven to be one of the most accomplished EVA trainees in
a rigorous testing program organized by John Grunsfeld. Mike holds a Ph.D.
in Mechanical Engineering.

SM3B will initiate an exciting time for astronomy. The new Advanced Camera
for Surveys (ACS) will finally get its chance to show us its mettle with
over twice the field of view of WFPC2 [Wide Field Planetary Camera 2],
sampled with PC-like angular resolution, and with substantially greater
throughput. And with the experimental new technology of the NICMOS [Near-
Infrared Camera and Multi-Object Spectrometer] cryocooler, we have
reasonable prospects for reviving Hubble’s near-infrared capabilities.
After replacing the current solar arrays with smaller, more efficient rigid
arrays, we will be leaving Hubble with plently of electrical power for the
remainder of the mission (as well as a “new look”). And the changeout of
the aforementioned Power Control Unit will assure that we can take full
advantage of all those watts without fear of a major electical system
failure in the future.

Now that our EVA crew has been named, we are able to establish a launch-
readiness date of October 15, 2001 for the SM3B mission. However, there
remain some uncertainties about the availablity of Space Shuttle Columbia
in this time frame. Currently Columbia is undergoing a major overhaul in
Palmdale, CA. This includes extensive repairs of wiring problems, similar
to those carried out recently on all the other orbiters in the fleet. The
longer than expected repair process could force a further delay in SM3B
to February or March of 2002. However, our colleagues at NASA Headquarters
are currently trying to negotiate a “swap” of launch dates with another
mission that is now ahead of us in the queue for flight on Columbia so as
to prevent such a delay. Launch delays are especially bad news for the HST
(and Office of Space Sciences) budget. Previous launch slips have cost the
HST program many millions of dollars, drawn from our contingency funds.
Any future slips would threaten our ability to pay for future instruments,
WFC3 [Wide Field Camera 3] and COS [Cosmic Origins Spectrograph]. Needless
to say, we wish Code S [Office of Space Sciences] all the best in
attempting to stem this serious drain on the resources available for HST.