NASA's Dawn
spacecraft is in fine health after rocketing into space just after sunrise today,
ending a long wait for mission scientists even as the probe's own eight-year
journey to two large asteroids is just beginning.
For Dawn
principal investigator Chris Russell, the liftoff capped a 15-year effort to plunder
the secrets
of planetary formation from asteroids Vesta and Ceres. Russell and his
mission team watched
Dawn rise over its Cape Canaveral Air Force Station in Cape Canaveral, Florida
from the spacecraft's Launch Control Center.
"They
were very taken by today's launch," said Russell, of the University of
California, Los Angeles, of his colleagues in launch control after liftoff.
"In fact, my wife cried when she saw it."
NASA first
approved Dawn's
mission as part of its Discovery program for smaller, more affordable science
expeditions in 2001. Russell added that he first envisioned the mission using
its efficient ion drive in 1992.
Since then,
the mission has survived solar array dings, weather delays, rocket booster and
launch tracking issues, as well as cancellation in March 2006. The space agency
set the mission's current cost at about $357.5 million, not counting the cost
of Dawn's Delta 2 rocket.
Dawn is now
headed for a February 2009 swing past Mars before reaching its first space rock
target, the bright and rocky asteroid Vesta, in August 2011. The probe's novel Xenon
ion propulsion system is expected to guide it into orbit around Vesta for
almost a year, then send it off toward the icy dwarf planet Ceres -- the
largest space rock in the asteroid belt -- for a February 2015 rendezvous.
"The
spacecraft is safe, it is healthy and there's not a single [major] issue
aboard," said Keyur Patel, Dawn project manager at NASA's Jet Propulsion
Laboratory in Pasadena, Calif., after the successful launch.
He credited
Dawn's experienced mission team with tackling the last-minute hurdle of a
wayward ship that encroached within the launch range perimeter. The snag delayed
the probe's liftoff by about 14 minutes, after which the ship moved clear of
the launch range in time for a 7:34 a.m. EDT (1134 GMT) space shot.
Dawn's two
expansive solar arrays, which measure about 65 feet (about 20 meters) from tip
to tip, successfully unfurled after liftoff and its primary science instruments
were found to be in good health, mission managers said. A few minor issues,
such as a one amp difference in the current produced by the two solar arrays,
have popped up, but none are considered serious enough to pose a problem, they
added.
"They're
all just fine tuning," Patel said.
By Friday
morning, Dawn is expected to have flown beyond the orbit of the moon as it continues
its outbound flight to the asteroid belt that sits between the orbits of Mars
and Jupiter.
Mission
managers plan to test its three ion engines within about five days. A series of
instrument checks of Dawn's optical camera, mapping spectrometer and gamma ray
and neutron detector will also be performed, though the tools won't be fully
calibrated until after the Mars flyby, Patel said.
"Every
time we launch a spacecraft, they all have their own personalities," Patel
said. "And what we're about to discover is what kind of personality Dawn
has; whether it's going to be a well-behaved child, or someone that's slightly
naughty."
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