NASA abandons hope for failing Kepler space telescope
Efforts to save a $600 million tool in
NASA's quest for life elsewhere in the
universe have been unsuccessful, the
space agency said -- but there's still life
left in the robotic planet hunter.
In May, a specialized gyroscopic wheel
used to point the Kepler Space Telescope
toward the sun failed, the second such
failed wheel. And despite months of
analysis and testing, the spacecraft will
never be restored to working order. But
despite the breakdown, Kepler has proven
a remarkable success, NASA said.
"Kepler has made extraordinary
discoveries in finding exoplanets including
several super-Earths in the habitable
zone," said John Grunsfeld, associate
administrator for NASA's Science Mission
Directorate in Washington. "Knowing that
Kepler has successfully collected all the
data from its prime mission, I am
confident that more amazing discoveries
are on the horizon."
NASA said its efforts will now turn to
making the most of the research craft
while it still can.
Kepler is the first NASA mission capable of
finding Earth-size planets in or near the
habitable zone, the range of distance from
a star where the surface temperature of
an orbiting planet might be suitable for
liquid water. Launched in 2009, it has
discovered thousands of such planets,
including a pair just 1,200 light years
away.
Called Kepler-62-e and Kepler-62-f , the
news of their discovery came in April. But
shortly after, Kepler's mission ran into
trouble.
Kepler is powered by four solar panels,
and the spacecraft must execute a 90-
degree roll every 3 months to reposition
them toward the sun while keeping its eye
precisely aimed. Kepler launched with
four wheels to control that motion -- two
of them have now failed.
On Aug. 8, engineers conducted a system-
level performance test to evaluate Kepler's
current capabilities. They determined that
the wheel which failed last year can no
longer provide the precision pointing
necessary for science data collection. The
spacecraft was returned to its point rest
state, which is a stable configuration
where Kepler uses thrusters to control its
pointing with minimal fuel use.
"At the beginning of our mission, no one
knew if Earth-size planets were abundant
in the galaxy. If they were rare, we might
be alone," said William Borucki, Kepler
science principal investigator at NASA's
Ames Research Center in Moffett Field,
Calif. "Now at the completion of Kepler
observations, the data holds the answer to
the question that inspired the mission:
Are Earths in the habitable zone of stars
like our sun common or rare?"
Kepler will continue working, and NASA
will look to reduce fuel consumption to
extend the lifespan of the spacecraft. For
example, a different mode of steering
Kepler will enable NASA to extend its life
by years, explained Charles Sobeck,
deputy project manager with Ames
Research Center.
"We're not down and out. The spacecraft
is safe, it is stable," Sobeck said in May.
And regardless, Kepler is already a win for
NASA.
"The mission itself has been spectacularly
successful," he added. Most other
scientists agree.
The quest for "exoplanets" has generated
enormous interest among the public and
with scientists. And it will continue. A
second mission will launch in 2017 and
will use the same method that Kepler has
used to continue the mission; it will seek
the closest exoplanet -- which may be
under two dozen light years away.
The James Webb Space Telescope will also
help in the quest for life in the universe.
