[meteorite-list] Deep Impact Successfully Releases Impactor

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.cfm?release=2005-108

DC Agle (818) 393-9011
Jet Propulsion Laboratory, Pasadena, Calif. 
 
Dolores Beasley (202) 358-1753
NASA Headquarters, Washington 
 
Lee Tune (301) 405-4679
University of Maryland, College Park
 
2005-108 

Deep Impact Status Report
July 03, 2005 

One hundred and seventy-one days into its 172-day journey to comet 
Tempel 1, NASA's Deep Impact spacecraft successfully released its 
impactor at 11:07 p.m. Saturday, Pacific Daylight Time (2:07 a.m. 
Sunday, Eastern Daylight Time). 

At release, the impactor was about 880,000 kilometers (547,000 miles) 
away from its quarry. The separation of flyby spacecraft and the 
washing-machine-sized, copper-fortified impactor is one in a series 
of important mission milestones that will cap off with a planned 
encounter with the comet at 10:52 p.m. Sunday, PDT (1:52 a.m. on 
July 4, EDT). 

Six hours prior to impactor release, the Deep Impact spacecraft 
successfully performed its fourth trajectory correction maneuver. The 
30-second burn changed the spacecraft's velocity by about one kilometer 
per hour (less than one mile per hour). The goal of the burn is to 
place the impactor as close as possible to the direct path of 
onrushing comet Tempel 1. 

Soon after the trajectory maneuver was completed, the impactor 
engineers began the final steps that would lead to it being ready for 
free flight. The plan culminated with activation of the impactor's 
batteries at 10:12 p.m., PDT (1:12 a.m. Sunday, EDT). Deep Impact's 
impactor has no solar cells; the vehicle's batteries are expected to 
provide all the power required for its short day-long life. 

In order to release the impactor, separation pyros fired allowing a 
spring to uncoil and separate the two spacecraft at a speed of about 
35 centimeters per second (0.78 mile per hour). 

With Tempel 1 closing the distance between it and impactor at about 
10 kilometers (6 miles) per second, there is little time for mission 
controllers to admire their work. Twelve minutes after impactor release 
the flyby began a 14-minute long divert burn that slowed its velocity 
relative to the impactor by 102 meters per second (227 miles per hour), 
moving it out of the path of the onrushing comet nucleus and setting the 
stage for a ringside seat of celestial fireworks to come less than 24 
hours later. 

Deep Impact mission controllers have confirmed the impactor's S-band 
antenna is talking to the flyby spacecraft. All impactor data including 
the expected remarkable images of its final dive into the comet's nucleus 
will be transmitted to the flyby craft -- which will then downlink them 
to Deep Space Network antennas that are listening 134 million kilometers 
(83 million miles) away. 

While all is going as expected on the Deep Impact spacecraft the comet 
itself is putting on something of a show. The 14-kilometer-long 
(8.7-mile-long) comet Tempel 1 displayed another cometary outburst on 
July 2 at 1:34 a.m. PDT (4:34 a.m.EDT) when a massive, short-lived blast 
of ice or other particles escaped from inside the comet's nucleus and 
temporarily expanded the size and reflectivity of the cloud of dust and 
gas (coma) that surrounds it. The July 2 outburst is the fourth observed 
in the past three weeks. 

Three of the outbursts appear to have originated from the same area on the 
surface of the nucleus but they do not occur every time that that area 
faces the Sun. 

"The comet is definitely full of surprises so far and probably has a few 
more in store for us," said Deep Impact Project Manager Rick Grammier of 
NASA's Jet Propulsion Laboratory, Pasadena, Calif. "None of this overly 
concerns us nor has it forced us to modify our nominal mission plan." 

Information and images from a camera aboard Deep Impact's impactor and 
flyby spacecraft can be watched in near-real time at www.nasa.gov/deepimpact . 

For additional information about Deep Impact on the Internet, visit 
http://deepimpact.jpl.nasa.gov . 

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http://www.nasa.gov/mission_pages/deepimpact/multimedia/imp-mri-070305.html

Separation Anxiety Over for Deep Impact
07.03.05 

[Image of the impactor taken after separation]

This image of Deep Impact's impactor probe was taken by the mission's 
mother ship, or flyby spacecraft, after the two separated at 11:07 p.m. 
Pacific time, July 2 (2:07 a.m. Eastern time, July 3). The impactor is 
scheduled to collide with comet Tempel 1 at 10:52 p.m. Pacific time, 
July 3 (1:52 a.m. Eastern time, July 4). The impactor can be seen at 
the center of the image. 

Image credit: NASA/JPL-Caltech