[meteorite-list] Russians Now Preparing for Re-Entry of Failed Mars Probe (Phobos-Grunt)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 18 Dec 2011 18:22:38 -0800 (PST)
Message-ID: <201112190222.pBJ2McaW002038_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1112/17reentry/

Russians now preparing for re-entry of failed Mars probe
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
December 17, 2011

Russia's $163 million Phobos-Grunt Mars probe, stranded in low-Earth
orbit after a malfunction following launch Nov. 8, is expected to fall
back into Earth's atmosphere next month, Russian officials confirmed
Friday.

The massive spacecraft, still loaded with 11 tons of rocket fuel, will
burn up during entry, but 20 to 30 pieces of debris, totaling several
hundred pounds, are expected to survive atmospheric heating, hitting the
ground somewhere between 51.5 degrees to either side of the equator.

The spacecraft is stranded in an 89.2-minute orbit with a low point, or
perigee, of 125 miles and a high point, or apogee, of 171 miles. The
Russian space agency Roscosmos said re-entry is expected between Jan. 6
and 19. Ted Molczan, a respected independent satellite tracking expert,
calculates entry will occur around Jan. 11, plus or minus 5 days.

Whenever it falls, this will be the third uncontrolled re-entry of a
large satellite since September. NASA's 6.3-ton Upper Atmosphere
Research Satellite fell back to Earth late Sept. 23 U.S. time, showering
debris harmlessly into the south Pacific Ocean, and wreckage from
Germany's 1.7-ton ROSAT X-ray telescope fell without incident into the
Bay of Bengal on Oct. 23.

Russian space officials are hoping Phobos-Grunt follows suit, with any
debris impacting in unpopulated areas, but accurate predictions will not
be possible until a few days, or even hours, before re-entry. Roscosmos
and the Russian defense ministry have set up a task force to monitor
Phobos-Grunt's trajectory and eventual fall to Earth.

In a statement, Roscosmos, the Russian federal space agency, said the
spacecraft's propellant -- highly toxic nitrogen tetroxide and
dimethylhydrazine rocket fuel -- will burn up in the atmosphere and
poses no threat to the public. Likewise, the agency said that 10
micrograms of radioactive Cobalt-57, used in one of the spacecraft's
experiments, would not pose a health threat or have any adverse
environmental threat.

Perched atop a two-stage Zenit-2 rocket, Phobos-Grunt was launched Nov.
8 from the Baikonur Cosmodrome in Kazakhstan. It successfully reached
its preliminary parking orbit, but the spacecraft's main propulsion
module, or MDU, did not ignite as expected for the first of two "burns"
to boost the craft onto an interplanetary trajectory to Mars.

The probe's solar arrays apparently deployed as planned, indicating the
spacecraft had power and was not limited to on-board batteries. Amateur
satellite trackers said Phobos-Grunt appeared to be steady and not
flashing as one would expect if it was tumbling. But a throw-away fuel
tank that normally would have been jettisoned after the initial
Earth-departure rocket firing apparently remained in place, possibly
blocking a critical low-gain antenna.

Engineers made multiple attempts to communicate with the spacecraft
during passes over Russian ground stations, sending commands to initiate
contact and perhaps to reboot the flight computer. European Space Agency
ground stations also were used to "listen" for telemetry and to send
commands in hopes of establishing communications.

On Nov. 21, the launch window for a normal trajectory to Mars closed,
ending any chance for the planned mission even if the spacecraft could
be recovered. The next night, an ESA ground station in Perth, Australia,
finally heard signals from Phobos-Grunt, according to Anatoly Zak's
RussianSpaceWeb <http://www.russianspaceweb.com/>, but it's not clear
whether any meaningful data was received then or during a handful of
subsequent contacts.

Phobos-Grunt was the first interplanetary spacecraft launched by Russia
since 1996 when an ambitious Mars mission was lost in a launch failure.
Of the 19 unmanned Russian Mars missions launched prior to Phobos-Grunt,
15 were outright failures. NASA's record currently stands at 13
successes in 18 previous missions, not counting the $2.5 billion Mars
Science Laboratory, which was launched toward the red planet Nov. 26.

Phobos-Grunt was expected to reach Mars in October 2012. The flight plan
called for the spacecraft to jettison its propulsion module, used for
trajectory correction maneuvers and to brake into orbit, and release a
small Chinese orbiter.

In early 2013, the Russian mother craft was to maneuver itself to a
precisely orchestrated landing on Phobos, one of two small martian
moons. A half-pound of soil -- "grunt" in Russian -- was to be collected
and launched back to Earth in 2014 for detailed laboratory analysis.
Received on Sun 18 Dec 2011 09:22:38 PM PST