This story
was updated at 6:55 p.m. EST.
A NASA probe carried into space earlier today by
a Boeing Delta 2 rocket has deployed its mission-critical solar array, though
engineers are working to understand a glitch that pushed the
spacecraft into a fault-protection mode just after launch.
The spacecraft, Deep Impact, apparently entered a "safe-mode" - a condition
normally used in the event of a problem - after launch, but is healthy, agency
spokeswoman Natalie Godwin told SPACE.com.
The $330-million Deep Impact mission launched today at 1:47:08 p.m. EST
(1847:08 GMT), after favorable weather conditions and a relatively smooth
countdown allowed
an on-time liftoff from Launch Pad 17B. Nine strap-on solid rocket
boosters aided Delta 2's space shot.
"We did have a perfect launch
actually," said NASA launch manager Omar Baez just after liftoff.
But it was after the launch, while Deep Impact was on
its own, that a glitch - mostly likely caused by a too-low temperature
limit in propulsion system heaters - triggered the fault-protection
mode, which mission engineers hope to fix in the next 24 hours, according to
SpaceFlightNow reports.
Ground controllers initially experienced difficulty
confirming solar panel deployment, but later confirmed that Deep Impact unfurled its
solar array, used to generate power during spaceflight, then turned
them toward the Sun using onboard thrusters as planned, NASA officials said.
There were also
some minor prelaunch concerns, but all were overcome by launch time,
Baez said.
Those
concerns included high-level winds early in the day, the loss of a
critical radar to track Deep Impact's liftoff (which returned before launch), as
well as the loss of second stage telemetry during an engine burn to leave Earth
orbit, NASA officials said.
Successful spacecraft
separation
About 35 minutes into the
flight, at 2:21 p.m. EST (1921 GMT), Deep Impact successfully separated from
its third-stage booster and as it flew over South Africa.
NASA's
Jet Propulsion Laboratory (JPL) in Pasadena, California is managing Deep
Impact's comet- bound spaceflight.
Deep
Impact is actually a composite of two vehicles: a Flyby mothership designed
to observe Tempel 1 from a distance while the spring-loaded Impactor
probe carves a chunk out of comet during a July 4 rendezvous set
to occur 83 million miles (about 133 million kilometers) from Earth.
"The
real goal of Deep Impact is to understand how the interior of a comet is
different from its surface," said University of Maryland astronomer Michael
A'Hearn, the mission's principal investigator, an hour before launch. "We want
to excavate as deep a hole as we can to get down to the primitive material."
While the actual impact with Tempel
1 is expected to occur while both Tempel 1 and the Deep Impact probes are 83
million miles away from Earth, the NASA spacecraft will traverse about 268
million miles (431 million kilometers) in the six months - quite brief for a
deep space mission - it will spend flying toward its cometary
target.
"It's exciting, but it's a
fast mission from launch to encounter," Don Yeomans, a senior research scientist
with the Deep Impact mission at JPL, told SPACE.com. "We don't have a great deal of
time to calibrate the instruments."
Today's launch marked the first
space shot by NASA - or anyone else for that matter - for
2005.
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