[meteorite-list] December Deadline for Stranded Russian Mars Probe (Phobos-Grunt)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 15 Nov 2011 08:38:34 -0800 (PST)
Message-ID: <201111151638.pAFGcY30014155_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1111/14phobosgrunt/

December deadline for stranded Russian Mars probe
BY STEPHEN CLARK
SPACEFLIGHT NOW
November 14, 2011

Russia has until early December to establish contact with the stranded
Phobos-Grunt Mars probe and send it toward the Red Planet, the head of
the Russian space ageny said Monday.
 
Speaking to reporters after the launch of a three-man crew to the
International Space Station, the chief of the space agency said
Phobos-Grunt is in control of its flight and is maintaining its
orientation toward the sun to generate electricity.

But controllers have not communicated with the probe since it launched
Nov. 8. Phobos-Grunt's main propulsion system did not ignite for either
of two planned firings to propel itself out of low Earth orbit and on a
course to Mars.

Vladimir Popovkin, head of Roscosmos, said the 29,000-pound spacecraft
should remain in orbit until January, but the planetary window to reach
Mars closes in early December. Launches to Mars are only possible
approximately every 26 months when the planets are in the correct
position in the solar system.

If engineers can't recover Phobos-Grunt, it will continue flying in
orbit and crash back to Earth in the next month or two.

Nicholas Johnson, a NASA orbital debris expert, said Friday he expects
Phobos-Grunt to fall back into Earth's atmosphere around late December.

Popovkin said it will only be possible to further pinpoint the timeframe
of Phobos-Grunt's re-entry when it reaches an altitude of 180
kilometers, or about 112 miles. As of late Monday, Phobos-Grunt was
orbiting between 129 miles and 205 miles above Earth, according to U.S.
military tracking data.

The source of the uncertainty in the timing of the potential re-entry is
fluctuating solar activity, which can cause the atmosphere to expand and
contract, changing the effect of drag on orbiting satellites.
 
Because Phobos-Grunt is in a low-altitude orbit, communications stations
only have about seven minutes to attempt to contact Phobos-Grunt on each
pass, Popovkin said.

Without two-way communications, engineers are unable to diagnose what
went wrong after launch or upload new software and commands to fire
Phobos-Grunt's engine.

Popovkin's comments were the first official statement from Roscosmos on
the Phobos-Grunt mission since Nov. 9. Russian news reports since then
quoted unnamed sources and outside experts, but the leadership of
Roscosmos had been silent until Monday.

The space agency chief rejected accusations the Phobos-Grunt probe was
launched with design flaws.

Popovkin also stressed a re-entry of Phobos-Grunt would pose no threat
to Earth, saying its full load of toxic rocket propellant inside
aluminum fuel tanks would explode high in the atmosphere and pose no
danger to the public.

Johnson also said aluminum tanks would rupture and explode during
re-entry, whether the propellant inside was frozen or liquid.
Phobos-Grunt, which was designed to retrieve and return samples from the
Mars moon Phobos, carries an entry capsule with a heat shield that could
survive and reach the surface.
Received on Tue 15 Nov 2011 11:38:34 AM PST