[meteorite-list] Russian Mars Mission Halted By Glitch in Low Earth Orbit

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 9 Nov 2011 00:19:58 -0800 (PST)
Message-ID: <201111090819.pA98JwBg016482_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1111/08phobosgrunt/
                
Russian Mars mission halted by glitch in low Earth orbit
BY STEPHEN CLARK
SPACEFLIGHT NOW
November 8, 2011

Russia's Phobos-Grunt mission, an audacious effort to retrieve samples
from a Martian moon, is stranded in low Earth orbit following a
successful liftoff Tuesday from Kazakhstan, according to Russian reports.

Two rocket burns were supposed to propel the massive probe on a course
toward Mars late Tuesday, but indications are the engine firings did not
occur, according to Vladimir Popovkin, head of the Russian space agency.

The revelation came after a successful blastoff on top of a Zenit 2FG
rocket at 2016 GMT (3:16 p.m. EST). Phobos-Grunt and an attached rocket
pack separated from the booster about 11 minutes later.

Radar trackers did not detect Phobos-Grunt in the expected orbit after
it was supposed to fire engines nearly three hours after liftoff. The
burn was timed to occur over South America and out of range of Russian
ground stations, which are limited in coverage over Europe and Asia.

"We had a difficult night, and we could not locate the spacecraft for a
long time," Popovkin said in a report by the Russian Novosti news
agency. "We now have its position. It was found that the propulsion
system failed. There was neither the first nor the second burn."

Popovkin said the spacecraft may not have issued the command for a
specially-designed rocket system to ignite, adding such an issue was
foreseen during the development of the mission. He also suggested there
could have been a problem with the craft's orientation and switching
from sun-tracking to star-tracking, according to the Novosti report.

A subsequent story in Novosti late Tuesday night said such a problem
could be due to software or hardware issues. If it was a software
glitch, the odds of recovery are good, while a hardware anomaly could
have more dire consequences for the mission, the report said.

A senior manager at NASA's Deep Space Network said there is no agreement
between the United States and Russia for tracking of the launch sequence
with the network's powerful communications antennas around the world.
The antennas could be made available if Russia requests aid, the
mananger said.

Engineers are evaluating whether the spacecraft can be recovered in time
to upload fresh commands to attempt more engine burns to aim for Mars.
According to Popovkin, ground teams have three days to try to devise a
new program for the burns toward Mars.

Because it didn't fire its engines as scheduled Tuesday, Phobos-Grunt
still has a full load of propellant to get to Mars if engineers can find
the cause of the problem and fix it.

In a report by the Interfax news agency, Popovkin said he would not
describe the mission as a failure yet.
 
After initially reaching an elliptical orbit a few hundred miles above
Earth, Phobos-Grunt was supposed to fire its main propulsion unit twice,
first to raise its altitude, then to inject itself on a trajectory to
escape Earth.

Neither burn occurred, meaning the spacecraft is probably still circling
Earth at altitudes between 120 miles and 215 miles. The orbit was
supposed to have an inclination angle of about 51.4 degrees to the equator.

The first rocket firing was supposed to raise Phobos-Grunt's maximum
altitude to more than 2,500 miles. A second burn would have accelerated
the spacecraft beyond escape velocity, the relative speed needed to
overcome the influence of Earth's gravity and head for Mars.

Phobos-Grunt should have been on an Mars-bound trajectory at 0120 GMT
(8:20 p.m. EST).

The $163 million mission's propulsion system is derived from the Fregat
upper stage, a hydrazine-fueled space tug that often places satellites
in high-altitude orbits above Earth. The Fregat has never been used on
an interplanetary mission before.

The Fregat-based main propulsion unit was supposed to stay attached to
Phobos-Grunt for course correct maneuvers and a critical braking burn to
arrive in orbit around Mars in October 2012.

After getting to Mars, the probe was supposed to jettison the propulsion
unit and deploy China's Yinghuo 1 orbiter, which rides piggyback on
Phobos-Grunt for the journey there.

By early 2013, Phobos-Grunt was scheduled to approach Phobos and study
the moon with remote sensing instruments, giving Russian scientists data
needed to select a landing site.

Using a laser altimeter and radar navigation sensor, Phobos-Grunt was
expected to descend to the surface of the moon in February 2013. Because
of the weak gravity field at Phobos, the probe must make a gentle
landing with little margin for error.

After scooping up rock with a robot arm and placing the samples in a
canister, Phobos-Grunt's return capsule was designed to depart the moon
and target a landing back on Earth in August 2014 with nearly a
half-pound of soil.

After sending its samples back to Earth, Phobos-Grunt's core spacecraft
was supposed to remain on Phobos for a continued science mission for up
to a year.
Received on Wed 09 Nov 2011 03:19:58 AM PST