Grim Prospects for Saving Phobos-Grunt

A Russian poster for Phobos-Grunt. (Credit: Roscosmos)

The latest news about Phobos-Grunt is not encouraging. Russian controllers have had no success in communicating with the Mars-bound lander, which is stuck in low Earth orbit due to a failure of its propulsion system. If they cannot communicate with the spacecraft soon and command the engines to fire it to Mars, the vehicle will make an uncontrolled re-entry into the Earth’s atmosphere with 10 tons of toxic fuel on board by early December, reports indicate.

Meanwhile, evidence is emerging that the communications failures are likely a result of poor spacecraft design and contingency planning.

Anatoly Zak at RussianSpaceWeb.com explains [emphasis mine]:

As one informed source on the Novosti Kosmonavtiki forum reported the main problem with controlling the spacecraft had stemmed from the fact that the probe’s low-gain antennas might’ve been abstracted by the external tank of the MDU propulsion unit, thus preventing signals from the ground reaching the flight control computers. In the meantime, the probe’s high-gain antenna was in folded position at that phase of the flight. To make the situation worse, for some unknown reason, the spacecraft would not downlink telemetry to the ground either.

A moderator on the online forum of the Novosti Kosmonavtiki magazine posted excerpts from a two-volume technical description of the Phobos-Grunt spacecraft published by its manufacturer, NPO Lavochkin. From the available information on the mission scenario it became clear that all operations onboard the spacecraft during its transfer from the initial parking orbit to the transfer orbit had been designed to be conducted exclusively under automated control and no two-way communications with ground stations would be possible. As a result, current attempts to control the spacecraft in its parking orbit were completely improvised. Still, one participant in the project maintained without much details that establishing control over the spacecraft was possible.

If true, then the Russians are guilty of poor contingency planning. At some point, planners had to have gamed out failure scenarios and built in a way to communicate with the vehicle in the event of a propulsion failure.

And what of the 10 tons of hydrazine and nitrogen tetroxide fuel on board? Two scenarios have emerged. In one, the spacecraft burns up over an unpopulated part of the ocean. The fuel, which has not frozen, burns up harmlessly in the upper atmosphere while any surviving debris ends up swimming with the fishes.

The second scenario is that the fuel freezes, meaning it could survive to hit the round. Three years ago, the United States shot down one of its reconnaissance satellites, USA-193, that had failed with a full load of hydrazine fuel using a missile fired from an a missile fired from an Aegis cruiser rather than risk that possibility. The resulting explosion broke the satellite up into smaller pieces with less of a chance of surviving re-entry. There were no reported incidents of contamination when the pieces entered the atmosphere.

There has been speculation in the Russian media that the military might try to shoot down Phobos-Grunt. However, this has been speculation only. Roscosmos has been almost as silent as their spacecraft since the mission began. There has been no update on the space agency’s website since an initial report of problems on Nov. 9. Whatever ends up happening, we can add a failure of public relations to Roscosmos’ problems with this mission.