Spaceflight Now Home





Mission Reports




For 11 years, Spaceflight Now has been providing unrivaled coverage of U.S. space launches. Comprehensive reports and voluminous amounts of video are available in our archives.
Space Shuttle
Atlas | Delta | Pegasus
Minotaur | Taurus | Falcon
Titan



NewsAlert



Sign up for our NewsAlert service and have the latest space news e-mailed direct to your desktop.

Enter your e-mail address:

Privacy note: your e-mail address will not be used for any other purpose.



Advertisement






Space Books






Orbit-raising commands fail to budge Phobos-Grunt probe
BY STEPHEN CLARK
SPACEFLIGHT NOW

Posted: November 29, 2011


Bookmark and Share

Plagued by an undiagnosed problem that stranded it in Earth orbit, Russia's Phobos-Grunt Mars mission remained quiet Tuesday after renewed attempts to coax the craft back into contact with ground controllers.


Artist's concept of the Phobos-Grunt lander at Mars. Credit: Roscosmos
 
European Space Agency officials transmitted signals to raise Phobos-Grunt's orbit Tuesday in hopes it would allow greater communications opportunities at a higher altitude, according to the agency's Twitter page.

The ploy didn't work, and the probe remains in a low-altitude orbit less than 200 miles above Earth.

Outfitted with a feedhorn antenna designed to attenuate the power of its radio signals, ESA's Perth ground station heard signals from Phobos-Grunt twice last week.

Perth's 49-foot dish antenna received limited telemetry from the spacecraft. ESA passed the data to engineers with NPO Lavochkin, the probe's prime contractor.

Details on communications attempts have come exclusively from ESA. Roscosmos, the Russian space agency, has not released an update on Phobos-Grunt since Nov. 24.

The Perth facility only has between six and eight minutes each time Phobos-Grunt flies overhead in sight of the station, providing limited windows for transmitting commands and receiving data.

Officials hoped raising the craft's orbit would lengthen communications passes and give engineers a better chance of recovering the mission, but the commands didn't work Tuesday.

ESA said Russia requested more orbit-raising commands to be transmitted Tuesday night and Wednesday morning. The outcome of those attempts will be known later Wednesday.

Engineers are adding a feedhorn antenna to ESA's tracking site at Maspalomas in the Canary Islands. The feedhorn device was added to ground stations to reduce the power of signal transmissions because Phobos-Grunt's computers may think the craft is on the way to Mars, when radio signals from Earth would be weaker than in orbit.

Phobos-Grunt was designed to release a Chinese orbiter around Mars, then touch down on the Red Planet's rocky moon Phobos and collect samples. It carries a return vehicle to shepherd the soil of Phobos back to Earth for analysis.

Phobos-Grunt has been stuck in its low-altitude orbit since liftoff Nov. 8. A rocket pack attached to the spacecraft was supposed to fire twice to accelerate the probe toward Mars, but neither firing occurred as planned in the hours after launch.

Without data to assess the 29,000-pound craft's health, Russian engineers were left in the dark about why the burns failed. Russia enlisted help from ESA and NASA to contact the probe, but NASA's deep space antenna in Goldstone, Calif., never received a signal.

NASA's deep space network stopped listening for Phobos-Grunt on Tuesday to prepare for Saturday's launch of the Mars Science Laboratory.

Because Phobos-Grunt's altitude is so low, experts say the fuel-laden craft will succumb to the affects of drag and fall back to Earth early next year. Nicholas Johnson, NASA's chief orbital debris expert, said the re-entry may occur in late January or February, but a specific time period won't be known until much later.

If Russia is unable to regain control of the spacecraft, it would plunge into the atmosphere uncontrolled with a full load of propellant.

John Glenn Mission Patch

Free shipping to U.S. addresses!

The historic first orbital flight by an American is marked by this commemorative patch for John Glenn and Friendship 7.
 U.S. STORE
 WORLDWIDE STORE

Final Shuttle Mission Patch

Free shipping to U.S. addresses!

The crew emblem for the final space shuttle mission is available in our store. Get this piece of history!
 U.S. STORE
 WORLDWIDE STORE

Celebrate the shuttle program

Free shipping to U.S. addresses!

This special commemorative patch marks the retirement of NASA's Space Shuttle Program. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Anniversary Shuttle Patch

Free shipping to U.S. addresses!

This embroidered patch commemorates the 30th anniversary of the Space Shuttle Program. The design features the space shuttle Columbia's historic maiden flight of April 12, 1981.
 U.S. STORE
 WORLDWIDE STORE

Mercury anniversary

Free shipping to U.S. addresses!


Celebrate the 50th anniversary of Alan Shephard's historic Mercury mission with this collectors' item, the official commemorative embroidered patch.
 U.S. STORE
 WORLDWIDE STORE

Fallen Heroes Patch Collection
The official patches from Apollo 1, the shuttle Challenger and Columbia crews are available in the store.
 U.S. STORE
 WORLDWIDE STORE

INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.