The Russians, working with Germany's DLR space lab, were trying for a major first. Phobos, named for the Greek god of fear, is only 15 miles across, but it is the larger of Mars' two known moons. It may be an asteroid that was captured by the gravity of Mars eons ago, and scientists would very much like to know what it is made of.
Apollo astronauts, and one Soviet probe, have brought back 800 pounds of rock and soil from the moon. And an American probe called Stardust returned minute samples from the tail of a comet in 2006. But Mars and its moons have been seen as the next destination in space.
NASA's Opportunity rover, which landed on Mars in 2004, is still working, and a new, larger one, called Curiosity, is scheduled for launch Nov. 25. In the half century since the space age began, the Russian space program has tried and failed repeatedly to reach Mars.
Gina Sunseri of ABC News contributed reporting. Additional information from The Associated Press.