An artist's conception shows the Phobos-Grunt probe orbiting Mars. The spacecraft, which was designed to land on the Martian moon Phobos, has been stuck in Earth orbit since its launch on Nov. 9.
Russia's stranded Phobos-Grunt spacecraft reportedly has lost its main opportunity to go to Mars, land on one of its moons and return to Earth with a sample. Nevertheless, efforts to revive it continue.
Little information has come from the Russian Space Agency since the 13-ton probe was launched on Nov. 9, but reports from Russian news outlets say that controllers couldn't make contact before the planned window of opportunity closed today for the round trip to Mars and its moon Phobos.
Phobos-Grunt ("Phobos-Soil") was designed to scoop up a soil sample from Phobos and bring it back to Earth. It was also supposed to deliver a 250-pound (115-kilogram) Chinese mini-orbiter to study Mars' atmosphere. Before launch, Phobos-Grunt was hailed as Russia's comeback try for interplanetary exploration. But since the orbital glitch, it's been viewed as one more in a long string of failures for Russian Mars probes.
The Interfax news agency quoted an unnamed source in the space industry as saying that there was still an outside chance of going ahead with the trip to Phobos. "This would be possible if Phobos-Grunt received a new flight program, which would involve acceleration with the use of complex ballistic maneuvers, for instance, through the moon and with high fuel expenditure," the source was quoted as saying. "But by mid-December, even this opportunity to fire the spacecraft toward Mars will be gone."
For days, observers have been talking about a potential "consolation prize" for the $163 million mission: perhaps a trip to the moon and back, or to an asteroid. But this assumes that Russian Mission Control will be able to establish contact, upload new instructions and have the probe fire its engines properly to get out of Earth orbit. None of those tasks has yet been achieved.
So what's the problem? Here's one of the leading hypotheses: For some reason, a fault led to the probe's failure to fire its engines for leaving Earth orbit, but Mission Control can't send the commands to reset the software because the fuel tanks are blocking an antenna that needs to be clear.
NASA and the European Space Agency have been trying to help the Russians make contact, and all those efforts are continuing. At one point, orbital debris experts said Phobos-Grunt's orbit was on a decaying track that would lead to a fiery re-entry in December. But satellite observers now say the orbit has been more stable than initially predicted, and re-entry may be held off until January or later. It's almost as if Phobos-Grunt is trying to save itself.
The probe carries about 10 tons of toxic hydrazine and nitrogen tetroxide propellants, plus a smidgen of radioactive cobalt-57. Experts are debating whether the fuel would burn up in the atmosphere, or whether some of it would survive the fall and cause an environmental problem. Chances are that the debris from Phobos-Grunt would fall into the ocean, as was the case for NASA's UARS satellite and Germany's ROSAT satellite. But you can expect to hear more about the toxic-spill angle as the time of re-entry approaches — unless, that is, the spacecraft undergoes a miraculous resurrection.
In the meantime, NASA's next Mars probe — a one-ton rover known as Curiosity or Mars Science Laboratory — is due for launch on Saturday. The plan for that $2.5 billion mission is nearly as ambitious as Phobos-Grunt's. The six-wheeled, car-sized rover will have to be lowered to the Martian surface next August from a hovering "sky crane." Let's hope the Great Galactic Ghoul sees fit to spare Curiosity, if not Phobos-Grunt.
Update for 8:30 p.m. ET: David Warmflash, the lead investigator for the Phobos-LIFE experiment aboard Phobos-Grunt, says in a Twitter update that the "window for going to Mars [is] still open, not window for going and returning with Phobosian sample." I've tweaked this posting to reflect that scenario.
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