STS-125 Mission Will Service Orbiting Telescope
Shuttle astronauts will
make one final house call to NASA's Hubble Space Telescope as part
of a mission to extend and improve the observatory's capabilities
through 2013.
NASA Administrator Michael Griffin announced plans for a fifth
servicing mission to Hubble Tuesday during a meeting with agency
employees at NASA's Goddard Space Flight Center, Greenbelt, MD.
Goddard is the agency center responsible for managing Hubble.
"We have conducted a detailed analysis of the performance and
procedures necessary to carry out a successful Hubble repair
mission over the course of the last three shuttle missions. What we
have learned has convinced us that we are able to conduct a safe
and effective servicing mission to Hubble," Griffin said. "While
there is an inherent risk in all spaceflight activities, the desire
to preserve a truly international asset like the Hubble Space
Telescope makes doing this mission the right course of action."
The decision reverses an earlier determination by former NASA
Administrator Sean O'Keefe that, in the wake of the 2003 loss of
Columbia, a mission to the telescope would be too
risky -- as there is no "safe haven" option available
if problems develop with the orbiter. As Hubble is at a higher
orbit than the International Space Station, it would be impossible
for the shuttle to dock with the station during its mission.
There was also concern such a mission would be impossible to
accomplish prior to the planned retirement of the space shuttle.
Due to recent successes in missions to the ISS, however, NASA
believes the timeframe can accomodate such a mission.
The flight is
tentatively targeted for launch during the spring to fall of 2008.
Mission planners are working to determine the best location and
vehicle in the manifest to support the needs of Hubble while
minimizing impact to International Space Station assembly. The
planners are also investigating the best way to support a launch on
need mission for the Hubble flight, should problems develop with
the telescope beforehand.
The present option will keep Launch Pad 39-B at Florida's
Kennedy Space Center available for such a rescue flight should it
be necessary.
Griffin also announced the astronauts selected for the mission.
Veteran astronaut Scott D. Altman will command the final space
shuttle mission to Hubble. Navy Reserve Capt. Gregory C. Johnson
will serve as pilot. Mission specialists include veteran
spacewalkers John M. Grunsfeld and Michael J. Massimino and
first-time space fliers Andrew J. Feustel, Michael T. Good and K.
Megan McArthur.
Astronauts will attach two new instruments to the telescope. The
Cosmic Origins Spectrograph (COS) is the most sensitive ultraviolet
spectrograph ever flown on Hubble. The instrument will probe the
cosmic web, the large- scale structure of the universe whose form
is determined by the gravity of dark matter and is traced by the
spatial distribution of galaxies and intergalactic gas.
The Wide Field Camera 3 (WFC3) is a new camera sensitive across
a wide range of wavelengths (colors), including infrared, visible,
and ultraviolet light. It will have a broad inquiry from the
planets in our solar system to the early and distant galaxies
beyond Hubble's current reach, to nearby galaxies with stories to
tell about their star formation histories.
Other planned work includes installing a refurbished Fine
Guidance Sensor that replaces one degrading unit of the three
already onboard. The sensors control the telescope's pointing
system. An attempt will also be made to repair the Space Telescope
Imaging Spectrograph. Installed in 1997, it stopped working in
2004. The instrument is used for high resolution studies in visible
and ultraviolet light of both nearby star systems and distant
galaxies, providing information about the motions and chemical
makeup of stars, planetary atmospheres, and other galaxies.
"Hubble has been rewriting astronomy text books for more than 15
years, and all of us are looking forward to the new chapters that
will be added with future discoveries and insights about our
universe," said Mary Cleave, NASA's associate administrator for the
Science Mission Directorate.
The Hubble servicing
mission is an 11-day flight. Following launch, the shuttle will
rendezvous with the telescope on the third day of the flight. Using
the shuttle's mechanical arm, the telescope will be placed on a
work platform in the cargo bay. Five separate space walks will be
needed to accomplish all of the mission objectives.
"The Hubble mission will be an exciting mission for the shuttle
team. The teams have used the experiences gained from Return to
Flight and station assembly to craft a very workable Hubble
servicing flight. The inspection and repair techniques, along with
spacewalk planning from station assembly, were invaluable in
showing this mission is feasible," said Associate Administrator for
Space Operations Bill Gerstenmaier. "There are plenty of challenges
ahead as the teams do the detailed planning and figure the best way
to provide for a launch on need capability for the mission. There
is no question that this highly motivated and dedicated flight
control team will meet the challenge."
The Hubble Space Telescope is an international cooperative
project between NASA and the European Space Agency.