fobos-grunt (also spelled phobos-grunt, also called phobos sample return mission) was an unmanned russian spacecraft. it was an attempted sample return mission to phobos, a moon of the planet mars. scientists intended phobos-grunt to orbit and study mars. it was meant to look at mars' atmosphere and dust storms, plasma and radiation. then, phobos-grunt should have landed on phobos and returned a 200 g soil sample to earth.