Russia is planning two uncrewed Mars missions, according to press reports.
The first, in 2009, is a mission to orbit Mars and land on the tiny moon Phobos, where a rover would roam for three years. There, it would collect samples of soil to bring back to Earth – the first ever if successful. The second mission, scheduled for 2015, is to place a lander on the surface of the Red Planet.
But Russia has had little success in its Martian missions. Since 1960, Russia, and the Soviet Union before it, has tried to send 17 probes to Mars – only three of those were unqualified successes.
The Phobos 1 and 2 missions were dispatched to the Martian moon in 1988, but one failed on the way because of a software error. The other made it into orbit around Mars but a computer glitch prevented it from deploying a lander to Phobos’ surface. Russia’s most recent attempt to conquer the Red Planet was in 1996, when its Mars-96 orbiter did not even get out of Earth orbit.
Russia has been working on a Phobos mission for several years, says a report by the UPI press agency. In theory, it should be easier to land on the Martian moons because a probe would only have to move alongside another orbiting object, rather than decelerate rapidly through the planet’s atmosphere. A sample return mission would also use less fuel escaping the tiny gravity of a moon compared to leaving the much larger planet.
Kicking up dust
A further advantage of landing on Phobos is that it is very close to Mars – just 9000 kilometres above the surface. From that vantage point, a spacecraft could also make detailed measurements of Mars.
The proximity of Mars means Phobos is likely to have pieces of the planet on it. When large meteorites crash into Mars, they kick up rocks and soil. The finest particles are launched into orbit around Mars, where Phobos sweeps some of them up.
But collecting grains of Martian dust from Phobos would not tell scientists a lot about where the particles originated or how old they are. “You learn a lot more about Mars if you know where the rock came from,” says Phil Christensen, a geologist at Arizona State University in Tempe, US, who has worked on several of NASA’s Mars missions.
Meteorites found on Earth that originated on Mars suffer the same drawback. “But the bottom line is we don’t know a lot about Phobos either,” he adds.
Martian moon base
The US has never devoted a mission to Phobos or its sister moon Deimos although other Martian orbiters have snapped pictures of the pair. The moons do not have the obvious allure of Mars: interesting climate, a history of water and the prospect of life.
“Phobos and Deimos don’t have those attractions, but they’re attractive in their own right,” says Fred Singer, president of the Science and Environmental Policy Project in Virginia, US. “Once you decide to do a proper manned missions, you should think about Phobos and Deimos.” Singer says setting up a crewed base on Deimos would be cheaper and easier than sending humans to the Martian surface.
A mission devoted to the moons could explain how the satellites are held together – whether they are piles of rubble loosely held together by gravity or solid chunks.
Most scientists assume the heavily cratered moons are captured asteroids, Christensen told New Scientist. But it is actually quite hard for a planet to capture an object into its orbit – most things just skim by. “So how it got there is a bit of an enigma,” Christensen says.