This
story was updated at 11:45 a.m. ET.
AUSTIN, Texas — The orbiting space telescope that
just won't quit collecting gobs of celestial data well beyond its expected
twilight is set for a major tune-up and upgrade, NASA scientists announced
today here at a meeting of the American Astronomical Society.
This servicing
mission will be the Hubble Space Telescope's fifth and last.
Word today
is that the Space Shuttle Atlantis could lift off in August with a crew of
seven astronauts and cargo of equipment, tools and new instruments for Hubble.
But that launch date could change. "That's dependent upon the shuttle
flights between now and the servicing mission," said NASA's Alan Stern,
associate administrator for the Science Mission Directorate in Washington, D.C. He added that safety always comes first.
Orbiting at
about 350 miles (563 kilometers) above Earth, Hubble is above the atmosphere and
doesn't have to contend with shifting pockets of air that distort images made
by ground-based telescopes. This atmospheric distortion is the reason stars appear
to twinkle.
Hubble's
clear view has meant, for one, that over its 16-plus years in orbit, the
telescope has sent back a spectacular photo album
of sci-fi-like jets from black holes, galaxies in all stages of evolution and
snapshots of planets in our own solar system.
"Hubble
is, without exaggeration, a national treasure," Stern said, "and all
of NASA is looking forward to seeing it receive this tune-up and upgrade."
The
public's love for Hubble, along with political pressure, has played a role in
NASA's decision to service the observatory, a mission deemed risky compared to
other shuttle ventures.
Hubble hugger
During the
11-day Hubble service mission, which will include five spacewalks, shuttle astronauts
will install two new science instruments plus a set of gyroscopes to help
stabilize the telescope, as well as batteries and thermal blankets to keep the
observatory operating until at least 2013.
Astronauts
will also install a soft capture mechanism that will allow a future unmanned
spacecraft to dock with Hubble in about 2020 and de-orbit it for a controlled plunge
and disposal in the ocean.
Leading the
spacewalks will be self-labeled "Hubble Hugger," astronaut John
Grunsfeld, who had told SPACE.com
last year he wanted to be on the mission.
"As
both an astronaut and an astronomer, the opportunity to go back to Hubble is
more than a dream come true," said Grunsfeld. "When we left Hubble in
2002, I was convinced it would be the last time I would see my friend Hubble
telescope," said Grunsfeld, wearing a NASA flight suit and space gloves.
However, he
noted, "This mission promises to be quite challenging."
For
instance, astronauts will attempt the first-ever on-orbit repair of two
existing instruments, the Space Telescope Imaging Spectrograph (STIS) and the
Advanced Camera for Surveys (ACS), which failed a year ago this month.
Installed
on Hubble in February 1997, the STIS separates incoming light into its
constituent colors, giving astronomers a chemical map of distant objects. Since
its deployment, STIS has been critical in the confirmation of black holes at
the centers of galaxies, made the first discovery of an atmosphere around an
exoplanet and helped confirm the age of the universe.
Better
science
Two additions
to Hubble's science cargo will include the Wide Field Camera 3, a
"panchromatic" camera, and the Cosmic Origins Spectrograph (COS).
The COS will probe the large-scale structure of the universe, the so-called cosmic
web, in which strands of galaxies transect seemingly empty space like a
gargantuan 3-D spider web. The universe's invisible "glue," called
dark matter and thought to make up about 85 percent of all matter in the
universe, gives the web its structure, astronomers say.
Astronomers
infer the existence of the cosmic web just as a child might know a Christmas
tree exists by looking at the colorful lights that outline its branches.
Instead of little bulbs, the stars and galaxies trace out the cosmic web.
In the end,
scientists expect to breathe new and improved life into Hubble.
"Our
goal for this mission is to leave Hubble at the apex of its scientific capabilities,"
said David Leckrone, Hubble senior project scientist at NASA's Goddard Space Flight Center in Maryland. The addition of new instruments along with repairs of
others should give astronomers a full "tool box" for resolving many
cosmic conundrums, Leckrone said.
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