Now it's looking as though the Russians may endure yet another failure. The latest mission, Phobos-Grunt ("grunt" is Russian for "ground"), is Russia's first attempt at Mars in a decade and a half. It successfully launched into earth orbit Tuesday on a Ukrainian Zenit rocket, but it failed to perform the engine firings necessary to send it on its way to the desired destination, the Martian moon Phobos.
The plan was for this spacecraft to grab a half-pound sample of the moon and return it all the way home for study; the craft would drop a conical capsule that would land at the Sary Shagan test range in Kazakhstan, where scientists would recover the sample. Phobos is interesting itself because it may be a captured carbonaceous asteroid, with potentially useful resources such as water, and it could potentially be a human base from which to stage missions to the Martian surface. Phobos-Grunt was also going to send several types of microbes and a soil colony on the round trip, the idea being to test whether life could survive such a trip through space—if it could, that would strengthen the argument that life here on earth may have been seeded from space. In addition, a Chinese orbiter (their first planetary mission ever) was piggybacking on the main vehicle, from which it planned to separate upon arrival in orbit around Mars.
But as of this writing, Phobos-Grunt is off-course, stranded in orbit around the earth. Ground controllers knew something was wrong Tuesday night when the craft didn't show up on radar where they expected it. It took a while to locate it, but once they did, it became clear that Phobos-Grunt hadn't automatically performed the maneuvers it was supposed to when it was over South America, out of Russian ground-station range.
The vehicle is reportedly in a safe mode, but its operators are in a race against time to save the mission. The first of the two burns planned for the spacecraft was supposed to raise the perigee (low point) of its orbit. The mission entered Earth orbit at 120 by 215 miles altitude, and an engine firing at apogee (the high point) would have raised a new high point of the orbit to more than 2500 miles of altitude, with the current apogee of 215 miles becoming the new perigee. All in all, the spacecraft would suffer much less drag at that new elevation.
Russian operators have had one bright moment: There was only a three-day window after the launch in which they could deploy the craft's solar panels before its batteries run out, and yesterday they pulled it off. But if Phobos-Grunt doesn't perform the burn and stays at an orbital low point of just 120 miles, its orbit will slowly decay with each dip into the upper atmosphere, and it will fall farther toward the earth, eventually to burn up. Current estimates are that they have a couple weeks to do the burn before this happens. Finally, if the spacecraft doesn't leave soon, Russia will miss its window to Mars. The planet would move too far away for them to reach it and return with the propellant on board.
If the craft does fall into the atmosphere, there is some concern about the danger on the ground. Because this mission was intended to go to Mars and return, it's carrying lots of propellant, and that propellant is a toxic combination of hydrazine for fuel and nitrogen tetroxide (a form of nitric acid) for the oxidizer. These propellants are hypergolic, which means that they combust on with each other without the need for an ignition source. That makes for very reliable rocket engines, and for that reason they've been used for decades in the American space programs. If the propellants on board Phobos-Grunt remain liquid, they will harmlessly burn up in the upper atmosphere. But if they freeze in the cold of space because of a lack of power for heaters, the frozen propellant chunks could survive all the way to the ground, making a nasty mess wherever they land.
According to Vladimir Popoin, the new head of the Russian Space Agency Roskosmos (he replaced the former head who was relieved after the launch failures a couple months ago), Russia is in with the vehicle, but doesn't yet know what went wrong. There is some speculation that Phobos-Grunt had a problem transitioning from the sun-tracker navigation system used in Earth orbit to a star-tracker needed for deep space.
Going to Mars is an arduous task. Americans have had better luck than the Russians, starting with the two Viking landers in the 1970s, and more recently the rovers Spirit and Opportunity, which lasted far longer than initially planned or expected. But there have been many American failures as well, including a case of what aviation types call "controlled flight into terrain"—when a planned orbiter crashed into the planet because of English/metric–unit confusion between NASA and the contractor. Over the decades, some have jokingly (but grimly) speculated that there is a "Great Galactic Ghoul" that tries to see to it, and often succeeds, that the planet remains unexplored. In this case, though, if the mission does fail, many will attribute it to the tight Russian space budget and an inexperienced team that hasn't attempted such a mission in 15 years.
We should learn Phobos-Grunt's fate in the coming days. If a software problem is the source of its trouble, there is a good chance of uploading some new commands and getting the mission back on track and on its way to Mars. If there is a problem with the hardware itself, however, the mission will probably be a failure, and the Ghoul will claim yet another victim.