[meteorite-list] Orbiting HiRISE Camera Saw Phoenix Heat Shield in Freefall

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 9 Jul 2008 17:26:20 -0700 (PDT)
Message-ID: <200807100026.RAA04663_at_zagami.jpl.nasa.gov>

FROM: Lori Stiles (520-360-0574; lstiles at u.arizona.edu)

Orbiting HiRISE Camera Saw Phoenix Heat Shield in Freefall
University of Arizona
July 9, 2008

Scientists running the High Resolution Imaging Science Experiment, known as
HiRISE, on NASA's Mars Reconnaissance Orbiter have processed more details in an
amazing image their camera captured as the Phoenix spacecraft descended through
Mars' atmosphere during its landing on May 25, 2008.

New analysis has turned up what likely is Phoenix's heat shield falling toward
Mars' surface, they conclude.

HiRISE, run from The University of Arizona, made history by taking the first
image of a spacecraft as it descended toward the surface of another planetary
body.

The image shows NASA's Phoenix Mars Lander, also run from the UA, when the
spacecraft was still tucked inside its aeroshell, suspended from its parachute,
at 4:36 p.m. Pacific Daylight Time on landing day. Although Phoenix appears to
be descending into an impressive impact crater, it actually landed 20
kilometers, or 12 miles, away.

Mars Reconnaissance Orbiter was about 760 kilometers, or 475 miles, away when it
pointed the HiRISE camera obliquely toward the descending Phoenix lander. The
camera viewed through the hazy Martian atmosphere at an angle 26 degrees above
the horizon when it took the image. The 10-meter, or 30-foot, wide parachute
was fully inflated. Even the lines connecting the parachute and aeroshell are
visible, appearing bright against the darker, but fully illuminated Martian
surface.

In further analyzing the image, the HiRISE team, supported by personnel from
NASA's Jet Propulsion Laboratory and Lockheed Martin Space Systems Co.,
discovered a small, dark dot located below the lander.

Phoenix was equipped with a heat shield that protected the lander from burning
up when it entered Mars' atmosphere and quickly decelerated because of
friction. Phoenix discarded its heat shield after it deployed its parachute.

"Given the timing of the image and of the release of the heat shield, as well as
the size and the darkness of the spot compared to any other dark spot in the
vicinity, we conclude that HiRISE also captured Phoenix's heat shield in
freefall," said HiRISE principal investigator Alfred McEwen of the UA's Lunar
and Planetary Laboratory.

The multigigabyte HiRISE image also includes a portion recorded by red,
blue-green and infrared detectors, and scientists have processed that color
part of the image.

HiRISE's color bands missed the Phoenix spacecraft but do show frost or ice in
the bowl of the relatively recent, 10-kilometer (6-mile) wide impact crater
unofficially called "Heimdall." The frost shows up as blue in the false-color
HiRISE data, and is visible on the right wall within the crater.

The HiRISE camera doesn't distinguish between carbon dioxide frost and water
frost, but another instrument called CRISM on the Mars Reconnaissance Orbiter
could.

The new details and color in the Phoenix descent image can be found on the
HiRISE Web site, http://hirise.lpl.arizona.edu.

The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion
Laboratory in Pasadena, Calif., for NASA?s Science Mission Directorate.
Lockheed Martin Space Systems is the prime contractor for the project and built
the spacecraft. The University of Arizona operates HiRISE, which was built by
Ball Aerospace and Technology Corp.

WEBLINKS:
HiRISE - http://hirise.lpl.arizona.edu
Mars Reconnaissance Orbiter - http://www.nasa.gov/mro

SCIENCE CONTACT:
Alfred McEwen (520-621-4573; mcewen at lpl.arizona.edu)
Received on Wed 09 Jul 2008 08:26:20 PM PDT