
As planned, the Russian space mission Phobos-Grunt* will blast off from Earth this October. It should take some 10 months to reach Mars space, aiming to land on Phobos, the bigger of the two Martian moons, though ‘bigger’ is relative here - the boulder-like Phobos (pictured) is less than 27 km (17 miles) long.
The probe will land very gently, for the gravity of Phobos is very slight, and leaving the little moon later will require a liftoff speed no more than about 35 km/h (22 mph). Compare this with our far more massive Earth, where the 1G gravity means that an escape velocity of some 40,000 km/h (25,000 mph) is needed.
If successful, Phobos-Grunt will collect soil samples, then return them to Earth for study. Bringing back samples from a moon is not something that’s been achieved since 1976, when Russia’s Luna 24 brought back samples from our own Moon.
Phobos-Grunt will also bring back the US-based Planetary Society’s LIFE capsule, with its cargo of hardy micro-organisms that have been transported all the way from Earth, to see if they can survive a long period while exposed to the space environment. To avoid possible contamination on their return, the LIFE capsule can withstand a 4000G crunch without breaking apart - making the capsule strong enough to withstand a disastrous crash-landing.
The video gives a good idea of the mission, including a fascinating look at the complex celestial trajectories needed to reach Phobos and back. If you like a musical background - Ravel’s Bolero - then crank up your speakers!
* The Russian word for soil is Фобос-Грунт, pronounced ‘grunt’.












































