Russia's lost-to-space Mars probe. Credit: Lavochkin Association

The wayward Russian Marscraft, Phobos-Grunt, is expected to soon dive into the Earth’s atmosphere, destroying itself during a fiery re-entry process.

Phobos–Grunt was launched on November 8 of last year, but due to a propulsion failure, the spacecraft was marooned in Earth orbit, not propelled on an Earth-escape trajectory to Mars.

The spacecraft’s mission was to land on Phobos – one of the two moons of Mars – and return to Earth samples of that body.

The spacecraft was declared lost by the Russian space agency, Roscosmos, in mid-December.

The lost-to-space spacecraft is now officially a target for the 12-member Inter-Agency Space Debris Coordination Committee, or IADC for short. This group of international partners will establish a coordinated prediction campaign focused on the fall of Phobos–Grunt.

Participants in this international campaign include NASA and Roscosmos – active members of the IADC.

When and where…a tough call

As for predicting the exact time Phobos-Grunt will fall – and over what part of the Earth the craft will re-enter – is a tough call.

“Right now, due to the large number of uncertainties in the orbit and space environment affecting the satellite, the indications are that Phobos-Grunt could reenter between January 13-17, between 51.4°N and 51.4°S,” said Heiner Klinkrad, Head of the European Space Agency’s (ESA) Space Debris Office.

ESA’s Space Debris Office, located at the European Space Operations Centre, Darmstadt, Germany, hosts the IADC reentry event database that is used to exchange orbit data and reentry predictions among IADC members.

According to its Russian owners, Phobos–Grunt has a mass of 13.5 tons, including about 11 tons of toxic propellant.

Fuel load

Analyses by Roscosmos and NASA indicate that the fuel tanks, filled with unsymmetrical dimethylhydrazine — UDMH — will burst high above the Earth, releasing its load of propellant and largely demise thereafter.

Roscosmos expects that at most, some 20 to 30 fragments of Phobos-Grunt leftovers may reach Earth’s surface. However, given that most of the Earth’s surface is covered by water, the chances of these fragments landing on terrain is very small.

“Since the beginning of the space age, there has been no confirmed report of an injury resulting from reentering space objects,” according to an ESA statement.

By Leonard David