[meteorite-list] Genesis Reentry Observed By Ground, Airborne Instruments

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Sep 20 13:10:51 2004
Message-ID: <200409201710.KAA09975_at_zagami.jpl.nasa.gov>

http://www.space.com/scienceastronomy/genesis_update_040920.html

Genesis Reentry Observed By Ground, Airborne Instruments
By Leonard David
space.com
20 September 2004

Researchers are assessing data captured by ground and airborne science
gear during the hypervelocity reentry of the Genesis sample return
capsule. That information may provide some clues as to why the capsule
made a destructive crash landing in Utah desert.

The capsule's parachute recovery system failed to deploy due to a
still-unknown cause. The Genesis hardware plowed into the Utah Test and
Training Range at nearly 200 miles per hour (322 kilometers per hour).

The sample capsule held precious cargo -- a stockpile of solar wind
specimens, embedded in fragile collector arrays. Genesis specialists
remain at the Utah site, sifting through spacecraft wreckage to recoup
meaningful science following the crash.

FISTA full of data

Nearly two dozen researchers flying onboard the U.S. Air Force's Flying
Infrared Signatures Technologies Aircraft (FISTA) got a front row seat
on September 8 to the Genesis sample return capsule's fiery reentry.

The reentering Genesis hardware was observed by airborne researchers
from a location just west of the Utah Test and Training Range and at an
altitude of 39,000 feet (11,900 meters). All instruments were reportedly
operational and ready for the observations.

"The reentry looked like a point of light with no visible wake, a bright
star falling gracefully down to Earth," notes a website dedicated to the
Genesis observations. Part of the reentry track was recorded in optical
as well as various infrared wavelengths that can capture the heat loads
experienced by the incoming, human-made fireball.

FISTA is operated by the U.S. Air Force 412 Test Wing at Edwards Air
Force Base, Edwards, California. During the decent, the aircraft
maintained a safe distance from the capsule's trajectory.

FISTA is a specially adapted NKC-135 Stratotanker previously used as an
aerial laboratory for the observation of the Leonid meteor storms. The
aircraft was further modified to observe the Genesis hardware screaming
through the atmosphere. New observational windows were added, along with
power units and antenna systems tied to the Global Positioning System
(GPS) satellite constellation.

Higher trajectory than expected

Experts from NASA Ames Research Center, located in California's Silicon
Valley, and the SETI Institute, Mountain View, California, took part in
observing the "artificial" meteor. Principal investigator and meteor
astronomer Peter Jenniskens of the SETI Institute lead the diverse and
independent science team.

The Genesis return capsule's trajectory was slightly different than
originally calculated, according to the SETI Institute's Jenniskens, a
meteor astronomer.

"The tracking was a little difficult because the craft came in a little
higher than expected, but we were able to get the data we wanted,"
Jenniskens told a reporter for the Air Force Print New Today.

Observers on the ground recorded the incoming projectile as it streaked
through the Earth's atmosphere. The capsule experienced peak heating
conditions as it decelerated near the Oregon/Nevada border en route to Utah.

The Genesis reentry data should be valuable to meteor specialists since
the sample container is an analog to meter-sized asteroids that deposit
organic material in Earth's atmosphere. Furthermore, the aerial
observation campaign was funded by the NASA Engineering and Safety
Center in Hampton, Virginia as a means to better understand the
phenomena of high-speed entry of return capsules.

Peak heating

Sandia National Laboratory experts used equipment to observe the
capsule's moment of peak heating and the instant the hardware felt the
strongest deceleration. "This data may prove of value in the
investigation why the Genesis parachutes did not open as expected,"
explains the Genesis observational website.

Although the reentering capsule was quite bright against the deep blue
sky at altitude, it was hard to observe from the ground. Initial reports
from ground teams indicate that the reentry was not seen visually
against the bright daytime sky, but was recorded by video cameras.

A NASA Marshall Space Flight Center team recorded the Genesis reentry on
four cameras spanning a 100 degree field of view above their northern
Nevada observing location.

A sonic boom was heard at all participating ground stations. An
infrasound record of the capsule cutting through the atmosphere was
acquired by a Los Alamos National Laboratory group operating at
Wendover, Nevada airport, situated near the Bonneville Salt Flats of
Utah's west desert.

Proving ground

Other scientists report success in optically tracking the incoming
Genesis sample return capsule. Data was collected and is being analyzed
in the hope of calibrating techniques used in watching for near-Earth
objects, such as worrisome asteroids.

"We do have a bunch of data to use in our attempts to discern how
closely we 'predicted' the time and location of the impact," said Donald
Yeomans, Supervisor of the Solar System Dynamics Group at the Jet
Propulsion Laboratory in Pasadena, California. "We'll
compare our after the fact predictions to asses the accuracy of our
Near-Earth Object monitoring system," he told SPACE.com.

Meanwhile, the Genesis science canister remains at the U.S. Army's
Dugway Proving Ground in Utah. Within a specially-fabricated clean room,
the sample container's outer wall is being cut away by technicians in
order to reach the solar wind samples inside.

At present, there are no concrete plans regarding the shipping date of
the Genesis capsule or its contents from Dugway to NASA's Johnson Space
Center (JSC) in Houston, Texas, advised Bill Jeffs, a Genesis spokesman
at JSC. "The plan is still to store the samples in the Genesis
cleanroom" he said, within the building at JSC that houses in various
labs collections of lunar samples, meteorites and cosmic dust - and
eventually will house the Stardust samples that arrive from space in
January 2006.

"I would expect that the Genesis Science Team will begin analyzing the
first samples during October or November," Jeffs said.
Received on Mon 20 Sep 2004 01:10:06 PM PDT