CAPE CANAVERAL, Fla. - After months of delay, the space
shuttle Atlantis is poised to launch seven astronauts today on a risky mission
to breathe new life into the Hubble Space Telescope.
The stakes are high. Hubble is 19 years old with two broken
cameras and a host of other systems in need of replacement or upgrades. Atlantis
is poised to fly the fifth and final mission to overhaul the iconic
space telescope.
"Particularly on this mission, the final mission, we're
going for broke," said David Leckrone, senior project scientist for Hubble.
"We've set the bar extraordinarily high for ourselves."
NASA expects near-perfect weather to launch Atlantis at 2:01
p.m. EDT (1801 GMT) from its seaside launch pad here at NASA's Kennedy Space
Center. The mission carries a price tag of $1.1 billion. NASA and the European
Space Agency have spent $10 billion on Hubble since the orbiting observatory's
conception and launch in 1990.
"We're ready to go give Hubble a hug," said veteran
Hubble repairman John Grunsfeld, an astrophysicist-turned-astronaut making
his third trip to the space telescope. "I hope Hubble's ready for us."
If all goes well, the astronauts will leave Hubble's vision
and science capability more powerful than ever before by the end of the 11-day
mission. Atlantis is also carrying a set of IMAX 3-D cameras to document
Hubble's last service call for a film slated to be released in spring 2010.
The mission carries extra risks, however.
The risk to reach Hubble
Hubble is beyond the reach of the International Space
Station, where astronauts would otherwise be able to take shelter for months if
their shuttle were damaged beyond repair. The observatory flies 350 miles (563
km) above Earth in a much different orbit than the space station, at 220 miles
(354 km) high.
The mission also has a higher chance being hit by space junk
or orbital debris. While at Hubble, there's a 1-in-229 chance Atlantis could be
seriously damaged by space trash. The astronauts will position the shuttle
special orientations to reduce that risk and fly down to a safer, cleaner orbit
soon after returning Hubble space near the mission's end.
NASA actually canceled the mission in 2004 because of that
risk and the Columbia shuttle tragedy that killed seven astronauts in 2003. The
Hubble mission was resurrected in 2006 after NASA successfully resumed shuttle
flights and tested heat shield inspection and repair techniques.
In case something goes wrong, NASA has primed a second spaceship
- the shuttle Endeavour - to fly
a rescue mission, if needed, to retrieve the Hubble-bound astronauts
before their air runs out - 25 days is all they carry on Atlantis. But NASA
believes the likelihood of actually needing the rescue flight to be extremely
remote, and each of the Atlantis astronauts say they're willing to take the
risk to save Hubble.
Hubble has made an amazing contribution to science and our
understanding of the universe, said veteran shuttle commander Scott
Altman. But while it has shed new light on the expansion of the universe, the
evolution of galaxies and the formation supermassive black holes, it is also
the vicarious eye through which people all over the world see
the cosmos.
"We can't travel 13 1/2 billion light-years," Altman said. "But
when Hubble brings that to us, it's like we're there."
Veterans lead the way
Launching with Grunsfeld are Altman, pilot Gregory C.
Johnson, and mission specialists Megan McArthur, Michael Good, Michael
Massimino and Andrew Feustel. Altman, Grunsfeld and Massimino have flown to
Hubble before. The rest of the astronauts are making their first spaceflight.
The astronauts plan to perform a five back-to-back
spacewalks to install two new cameras and attempt to repair the two ailing
instruments, which were never designed to be fixed in space. They also will
attempt some basic upgrades, like replacing broken gyroscopes and old batteries.
Hubble is designed to be overhauled every three years, but
the space telescope hasn't seen an astronaut service crew since 2002. Much of
that gap stemmed from the Columbia accident, but the most recent delay – a
seven-month slip – occurred last fall when a part aboard Hubble unexpectedly
broke down.
Because of the gap, Hubble needs a major overhaul.
"You can imagine if you had a car and you were driving every
day for seven years and never took it into the shop, you'd have quite a long
list of things to do," said Preston Burch, Hubble project manager at NASA's
Goddard Space Flight Center in Greenbelt, Md.
NASA has three chances to launch Atlantis this week before
the agency must stand down due to a military operation based out of the nearby
Cape Canaveral Air Force Station. If the shuttle does not launch by Wednesday,
NASA would wait until May 22 to wait out the military's operation and recharge
the new batteries for Hubble.
But just being poised for launch after years of delay - with
pristine weather expected - has given Hubble scientists cause to celebrate.
"To be within one day of it is remarkable and unbelievable,
and I have to persuade myself I'm not dreaming," Leckrone said, adding that
with prediction of clear weather he's confident Atlantis will launch today. "It
is going to go splendidly, I can feel it."
SPACE.com is providing continuous coverage of NASA's last
mission to the Hubble Space Telescope with senior editor Tariq Malik at Cape Canaveral
and reporter Clara Moskowitz in New York. Click here for mission
updates and SPACE.com's live NASA TV video feed.
advertisement
