UPDATE: Hopes Dim for Russian Mars Probe, Concerns Rise About Reentry

UPDATE: Russia’s Ria Novosti reports today that attempts to contact Phobos-Grunt overnight were unsuccessful. It quotes an unnamed Russian space industry source as saying that December 3 is the most likely date for the spacecraft to reenter if efforts to revive it are unsuccessful.

ORIGINAL STORY:

Russian engineers have not given up on contacting the Phobos-Grunt (Phobos-Soil) spacecraft that remains stranded in Earth orbit, but hopes for a happy outcome are dimming. Meanwhile, concerns are growing about the hazard posed by the spacecraft’s reentry because it is loaded with toxic fuel intended to take it to Mars.

The website of Russia’s space agency, Roscosmos, is eerily silent about the situation, focusing instead on the upcoming Sunday launch of a crew to the International Space Station. Itar-Tass, Russia’s major wire service, also has no new stories about the spacecraft. As pointed out by Emily Lakdawalla on her blog at The Planetary Society (which has an experiment aboard Phobs-Grunt), all that is available are unofficial postings at various websites and tweets on Twitter that paint a grim picture. Anatoly Zak’s RussianSpaceWeb.com site appears to be a good source of information, but also is unofficial.

According to Zak, a number of attempts have been made to contact the spacecraft, but all were unsuccessful. One problem is that the spacecraft’s low gain antenna is blocked by an external tank of a propulsion unit and the high gain antenna remains folded. Further attempts reportedly are planned.

If worse comes to worse and contact cannot be restored, the spacecraft will make an uncontrolled reentry through Earth’s atmosphere. Two recent uncontrolled reentries of defunct satellites — NASA’s UARS and Germany’s ROSAT — were uneventful, and since the Earth is 70 percent covered by water, the chances of space debris harming humans is relatively small. It is not zero, however, and a special concern exists with Phobos-Grunt.

The spacecraft is fully loaded with hydrazine and nitrogen tetroxide fuel to take it to Mars and return a sample of Mars’s moon Phobos. In 2008, the United States destroyed one of its own reconnaissance satellites, USA-193, that failed early in its mission and carried a full load of hydrazine fuel. The Department of Defense (DOD) argued that the frozen hydrazine posed a grave danger if debris landed in an inhabited area. DOD does not officially have an antisatellite (ASAT) program today, but was able to use a missile fired from an Aegis cruiser to hit the satellite and break it into smaller pieces that individually reentered within several days, minimizing the risk of damage to people or property. The “shootdown” occured about a year after China’s first successful ASAT test against one of its own satellites that created 3,000 pieces of debris that still plague low Earth orbit (LEO) operations. Some say the U.S. decision to destroy USA-193 was as much about demonstrating that the United States was not without its own capabilities to destroy LEO satellites, and without creating long lasting debris, as it was about preventing potential damage from the hydrazine.

Whatever the case may have been with USA-193, the question now is whether Russia might decide to attempt to destroy Phobos-Grunt in a similar manner and whether it might ask for U.S. assistance. For the time being, however, Russia continues its efforts to contact the spacecraft and send it on its way to Mars.