Russian space officials say they\'re pessimistic about the chances of salvaging a Mars mission probe that launched but failed to achieve the proper trajectory. The $170 million Phobos-Grunt probe launched successfully Wednesday but then failed to fire an engine that would send it on the correct course to the Red Planet, the BBC reported Thursday. The probe, intended to bring back soil samples from Mars\' moon Phobos, is stuck in Earth orbit and controllers may have only days to repair the fault before the onboard batteries run out. Attempts to communicate with Phobos-Grunt (\"grunt\" means \"earth\" or \"soil\" in Russian) have so far been unsuccessful. \"The scariest thing in this field is when you get no signal back from the craft,\" a source told RIA Novosti after Thursday\'s second failed attempt to establish contact with the probe. If the problem is in software and controllers can upload new commands, engineers have a chance of rescuing the mission, but if it is a hardware malfunction Phobos-Grunt is likely doomed, officials said. \"It looks like a serious flaw,\" Vladimir Uvarov, a former senior space official at the Russian Defence Ministry, told the government daily Rossiyskaya Gazeta. \"The past experience shows that efforts to make the engines work will likely fail.\"