April 07, 2009
Engineers have successfully ejected the dust cover from NASA's Kepler
telescope, a spaceborne mission soon to begin searching for worlds like Earth.
"The cover released and flew away exactly as we designed it to do," said
Kepler Project Manager James Fanson of NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "This is a critical step toward answering a question
that has come down to us across 100 generations of human history -- are
there other planets like Earth, or are we alone in the galaxy?"
Kepler, which launched on March 6 from Cape Canaveral, Fla., will spend
three-and-a-half years staring at more than 100,000 stars in our Milky Way
galaxy for signs of Earth-size planets. Some of the planets are expected to
orbit in a star's "habitable zone," a warm region where water could pool on
the surface. The mission's science instrument, called a photometer, contains
the largest camera ever flown in space -- its 42 charge-coupled devices (CCDs)
will detect slight dips in starlight, which occur when planets
passing in front
of their stars partially block the light from Kepler's view.
The telescope's oval-shaped dust cover, measuring 1.7 meters by 1.3 meters
(67 inches by 52 inches), protected the photometer from contamination before
and after launch. The dust cover also blocked stray light from entering the
telescope during launch -- light that could have damaged its sensitive
detectors. In addition, the cover was important for calibrating the
photometer.
Images taken in the dark helped characterize noise coming from the
instrument's
electronics, and this noise will later be removed from the actual
science data.
"Now the photometer can see the stars and will soon start the task of
detecting
the planets," said Kepler's Science Principal Investigator William Borucki at
NASA's Ames Research Center, Moffett Field, Calif. "We have
thoroughly measured
the background noise so that our photometer can detect minute changes
in a star's
brightness caused by planets."
At 7:13 p.m. PDT on April 7, engineers at Kepler's mission operations
center at
the Laboratory for Atmospheric and Space Physics, Boulder, Colo.,
sent commands
to pass an electrical current through a "burn wire" to break the wire
and release
a latch holding the cover closed. The spring-loaded cover swung open
on a fly-away
hinge, before drifting away from the spacecraft. The cover is now in
its own orbit
around the sun, similar to Kepler's sun-centric orbit. See an
animation of the event
at http://www.nasa.gov/mission_pages/kepler/multimedia/videos/cover.html .
With the cover off, starlight is entering the photometer and being
imaged onto its
focal plane. Engineers will continue calibrating the instrument using
images of stars
for another several weeks, after which science observations will begin.
Kepler is a NASA Discovery mission. NASA's Ames Research Center Ames
is the home
organization of the science principal investigator, and is responsible for the
ground system development, mission operations and science data
analysis. NASA's
Jet Propulsion Laboratory, Pasadena, Calif., manages the Kepler
mission development.
Ball Aerospace & Technologies Corp., Boulder, Colo., is responsible
for developing
the Kepler flight system and supporting mission operations.
For more information about the Kepler mission, visit
http://www.nasa.gov/kepler .
Media contacts: Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov
Mewhinney 650-604-3937
NASA's Ames Research Center, Moffett Field, Calif.
michael.s.mewhinney@nasa.gov
2009-065