This story was updated at 3:58 a.m. EDT.
PASADENA -- The Deep Impact mission is now
less than 24-hours and 500,000 miles from its final destination after the
spacecraft's Impactor probe successfully separated
from its Flyby mothership early Sunday morning.
The $333
million mission is slated to crash an 820-pound (371-kilogram) Impactor probe into Comet Tempel
1 and record the event via the Flyby mothership. The
collision is expected to take place at 1:52 a.m. EDT (0552 GMT) on July 4. A
cheer went up at 2:16 a.m. EDT (0616 GMT) when a mission controller announced
when Deep Impact's mission control received confirmation that the Impactor had separated from the Flyby mothership
at 2:07 a.m. EDT (0606 GMT).
"It went like
clockwork. Very good, we're very excited." Deep Impact project manager Rick Grammier, of NASA's Jet Propulsion Laboratory (JPL) here,
told reporters. "The systems were all nominal and we were within half a
kilometer of our target point before release and the release went very
well."
Researchers hope NASA's
Deep Impact mission will not just succeed in ramming a comet, but will punch
through Tempel 1's surface and reveal material that
has not been seen since the formation of the solar system 4.6 billion years
ago. They hope Deep Impact will not only yield information about the
composition of comets, but also shed light on the make-up of the early solar
system.
"The
first look at the data indicates that things couldn't have gone better,"
said Monte Henderson, program manager for Ball Aerospace and Technologies
Corp., the builders of NASA's Deep Impact spacecraft, via e-mail.
Following
separation, Flyby completed its divert engine burn and
moved safely out of the comet's path. After the initial separation, an alarm
went off onboard the Flyby vehicle. Mission
controllers ran through a systems check and concluded the spacecraft was on
track and the alarm could be ignored.
Grammier said that Flyby did manage to
capture and image of Impactor after the release.
"We didn't know if we
would quite get that or not, so that was a good thing," Grammier said.
"We
have been working on this program for five-and-a-half years, yet the major
milestones are still ahead of us," Henderson
said earlier Saturday evening, prior to the release.
In recent
weeks, Comet Tempel 1 has surprised mission managers
with a series of outbursts, the result of the comet's ever-closer proximity to
the sun. The first outburst was observed on June 14. A second outburst occurred
on June 22 and was photographed
by the Hubble Space Telescope.
"We
did not expect to see it," Henderson
said. "Our science team is really excited about what they are
finding."
The
outbursts--sprays of water vapor and carbon dioxide--are a result of portions of a
comet's icy crust heating up under the sun's light. According to Henderson, Tempel 1's outburst is at the moment, a singular,
predictable event. The comet completes one rotation on its axis every 42 hours,
with one outburst per rotation.
Henderson described the outbursts as
fog-like, dispersing over the surface of the comet, not an explosive plume that
could adversely affect the Impactor's ability to
pinpoint the brightest spot on the comet's surface. The team is not concerned
that the outburst will interfere with the impact. The last outburst is expected
to occur four hours prior to the collision said Henderson, and because of the outbursts
diffuse orientation, it disperses after about 30 minutes.
"I think we are seeing it at it's most
active," Henderson
said.
Today's
successful spacecraft separation is just the opening act for the Deep Impact
mission. The real fireworks begin tomorrow, when Impactor
begins its end-run toward Tempel 1 while Flyby, and a
myriad of orbital and ground-based telescopes, look on.
A
pre-impact press conference is currently set for 2:00 p.m. (1800 GMT) on July
3. NASA TV will provide live commentary of Deep Impact's arrival and expected
impact with Comet Tempel 1 beginning at 11:30 p.m.
EDT (0330 July 4 GMT).
You can
follow Deep Impact's comet crash live via SPACE.com's mission commentary
available here.
SPACE.com Staff Writer Tariq Malik
contributed to this story from New
York City.
Deep Impact: Viewer's Guide and Mission News