Saturday, January 14, 2012

Phobos-Grunt space probe heads to Earth

Russia's failed Mars probe, Phobos-Grunt, is about to fall back to Earth - quite probably on Sunday.

The spacecraft has been losing altitude rapidly in recent days and will soon be pulled into the top of the atmosphere where it will be destroyed.

Phobos-Grunt weighed some 13 tonnes at launch, but very little of this mass should make it through to the surface.

Russian space agency (Roscosmos) estimates suggest perhaps only 200kg will survive the fiery plunge.

Orbital debris experts say there are large uncertainties in predicting re-entry events and it is currently not possible to forecast precisely when or where on Earth the final descent will occur.

"The major uncertainty for prediction is the atmospheric density the spacecraft encounters in orbit, but it's also due to the orientation of the vehicle as it comes in," explained Prof Richard Crowther, the UK Space Agency's chief engineer.

"It can very quickly tumble and if pieces break off - that all changes the trajectory and where debris might impact." Read More