PARIS and WASHINGTON — The European Space Agency () ended its efforts to make contact with Russia’s Phobos-Grunt Mars spacecraft Dec. 2, surrendering to the realities of orbital mechanics, which have placed Mars orbit beyond the spacecraft’s reach until a new opportunity arises two years from now.
With its tracking antennas in Australia and Spain’s Canary Islands needed for other duties, the 19-nation ESA informed the Russian space agency, Roscosmos, and Phobos-Grunt prime contractor NPO Lavochkin that Europe would stop actively trying to contact the stranded spacecraft but would remain available for support should Russian authorities establish contact.
NASA had also lent its tracking assets to the Phobos-Grunt salvage effort but was unable to pick up any signals from the spacecraft, which was launched Nov. 8 on a mission intended to land on the martian moon Phobos and return samples to Earth. The spacecraft also carries a small Chinese satellite intended for Mars orbit.
“The mission is no longer feasible,” said Manfred Warhaut, head of operations at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany. In a conference call with journalists, Warhaut and ESOC operations engineer Wolfgang Hell, who had been in regular contact with Lavochkin, said Russia is unlikely to give up on Phobos-Grunt.
“We are not in a position to continue, but they definitely will not give up,” Warhaut said. “They will continue to try to send thruster commands” to get Phobos-Grunt’s engines to function.
Phobos-Grunt, whose Earth-orbit-escape thrusters failed to fire following its successful launch, is in an Earth orbit of about 200 kilometers by 340 kilometers. ESA and Russian officials have said that, given its current position, the spacecraft is likely to re-enter Earth’s atmosphere sometime in February.
With Mars no longer within reach — Mars and Earth are in the proper alignment for launches of Mars probes only for several weeks every two years — Russian authorities would appear to have two possible options. Both start with trying to raise the spacecraft’s orbit to buy more time. The most optimistic, but perhaps least realistic, scenario is to keep the satellite in orbit, fix whatever caused the failure of its engines to fire, and wait for the next Mars launch opportunity in two years. The more likely scenario if control of the satellite is re-established is to exercise some control over the timing and location of its atmospheric re-entry.
Hell and Warhaut said that from what they have been told by their Russian colleagues and others, the Phobos-Grunt fuel tanks are likely to burn up during atmospheric re-entry, reducing the threat that toxic fuel would rain on wherever the satellite’s pieces fall.
ESA and Russia signed a Phobos-Grunt cooperation agreement several years ago under which ESA’s tracking antennas would be used to communicate with Phobos-Grunt during its cruise phase, well after it had left Earth orbit.
“This is why we had a good understanding of the transponder characteristics” of the spacecraft, making it relatively easy for ESA to attempt to communicate with it, Warhaut said.
The agency modified its tracking antenna near Perth, Australia, and had succeeded in communicating with Phobos-Grunt Nov. 22 and Nov. 23. Subsequently a ground antenna at Russia’s Baikonur Cosmodrome in Kazakhstan also made contact with the satellite, according to Roscosmos.
ESA performed a similar modification of its tracking antenna in Maspalomas, Spain, but no communications with Phobos-Grunt were established.
“It is standard practice in this industry that if somebody needs help, we do our best,” Warhaut said.
NASA spokesman Michael Braukus said Roscosmos contacted the U.S. agency Nov. 11 seeking assistance in establishing contact with Phobos-Grunt. NASA, using its Deep Space Network and other assets, attempted to detect signals from the stranded craft until Nov. 22, when these resources had to be dedicated to the Nov. 26 launch of the agency’s Mars Science Laboratory probe, now making its way to the red planet.
Roscosmos, ESA and NASA are scheduled to begin negotiations the week of Dec. 7 on collaboration for a Mars exploration effort featuring launches in 2016 and 2018. Russia’s involvement in the project is now seen as indispensible to its full realization given budget limits at NASA and ESA.