[meteorite-list] I Love Comets

From: Meteorites USA <eric_at_meteoritecentral.com>
Date: Mon, 14 Feb 2011 10:52:24 -0800
Message-ID: <4D5979E8.2050301_at_meteoritesusa.com>

Flyby Time. Happy Valentine NExT
http://www.jpl.nasa.gov/news/news.cfm?release=2011-050&cid=release_2011-050&msource=11050&tr=y&auid=7771872

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NASA Spacecraft Hours From Comet Encounter
February 14, 2011
Stardust-Next Mission Status

PASADENA, Calif. -- As of today, Feb. 14, at 9:21 a.m. PST (12:21 p.m.
EST), NASA's Stardust-NExT mission spacecraft is within a
quarter-million miles (402,336 kilometers) of its quarry, comet Tempel
1, which it will fly by tonight. The spacecraft is cutting the distance
with the comet at a rate of about 10.9 kilometers per second (6.77 miles
per second or 24,000 mph).

The flyby of Tempel 1 will give scientists an opportunity to look for
changes on the comet's surface since it was visited by NASA's Deep
Impact spacecraft in July 2005. Since then, Tempel 1 has completed one
orbit of the sun, and scientists are looking forward to discovering any
differences in the comet.

The closest approach is expected tonight at approximately 8:40 p.m. PST
(11:40 p.m. EST).

During the encounter phase, the spacecraft will carry out many important
milestones in short order and automatically, as the spacecraft is too
far away to receive timely updates from Earth. These milestones include
turning the spacecraft to point its protective shields between it and
the anticipated direction from which cometary particles would approach.
Another milestone will occur at about four minutes to closest approach,
when the spacecraft will begin science imaging of the comet's nucleus.

The nominal imaging sequence will run for about eight minutes. The
spacecraft's onboard memory is limited to 72 high-resolution images, so
the imaging will be most closely spaced around the time of closest
approach for best-resolution coverage of Tempel 1's nucleus. At the time
of closest encounter, the spacecraft is expected to be approximately 200
kilometers (124 miles) from the comet's nucleus.

The mission team expects to begin receiving images on the ground
starting at around midnight PST (3 a.m. on Feb. 15 EST). Transmission of
each image will take about 15 minutes. It will take about 10 hours to
complete the transmission of all images and science data aboard the
spacecraft.

Live coverage on NASA TV and via the Internet begins at 8:30 p.m. PST
(11:30 p.m. EST) from mission control at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. Coverage also will include segments from
the Lockheed Martin Space System's mission support area in Denver. A
post-flyby news conference is planned on Feb. 15 at 10 a.m. PST (1 p.m.
EST).

For NASA TV streaming video, scheduling and downlink information, visit:
http://www.nasa.gov/ntv .

The live coverage and news conference will also be carried on one of
JPL's Ustream channels. During events, viewers can take part in a
real-time chat and submit questions to the Stardust-NExT team at:
http://www.ustream.tv/user/NASAJPL2 .

During its 12 years in space, Stardust became the first spacecraft to
collect samples of a comet (Wild 2 in 2004), which were delivered to
Earth in 2006 for study. The Stardust-NExT mission is managed by JPL for
NASA's Science Mission Directorate in Washington. Lockheed Martin Space
Systems in Denver built the spacecraft and manages day-to-day mission
operations.

A press kit and other detailed information about Stardust-NExT is online
at: http://stardustnext.jpl.nasa.gov .
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Regards,
Eric
Received on Mon 14 Feb 2011 01:52:24 PM PST