European Space Agency (ESA) engineers are open to collaboration with NASA and other agencies on a Mars Sample Return (MSR) mission, but they're not so sure about rigging the planned ExoMars rover with a sample cache for return to Earth later.
"The idea is an excellent one," said Piero Messina of the agency's exploration program office in Paris. "We all are very much interested in returning samples from Mars, but ... it all depends on what this caching means in terms of mass impact on the mission configuration, and as far as I know this is not yet clear."
NASA has raised the possibility of fitting a cache on ExoMars, now tentatively set for launch in 2013, along with its own 2009 Mars Science Lab mission (DAILY, Aug. 24). Essentially a wire-mesh basket where the rover's robotic arms could drop interesting rocks, the cache should simplify the MSR mission to follow by giving it a ready supply of pre-selected rocks already packaged for launch.
ESA is in the process of enlarging the payload on the ExoMars rover from 8 to 16.5 kilograms (18-36 pounds), and figuring out how to pay for the change. The new mission concept would fly on either an Ariane V or Proton instead of a Soyuz-Fregat, shortening the transit time to Mars from two years to about nine months. The target launch date would get the spacecraft into Mars orbit in October 2014, and there is a fallback launch date in 2015.
The European agency and its prime contractor, Thales Alenia Space, already are well along in their "enhanced baseline" redesign, which also would leave a stationary geophysical package on the planet for weather and other studies. The rover itself would be equipped with a drill that could pull and process samples from two meters (7 feet) beneath the surface.
Landing would be accomplished with a post-entry parachute system, followed by retro-rockets and a vented airbag that would cushion the final impact and then quickly deflate to keep the rover upright.
Messina told the International Astronautical Congress here Sept. 25 that the complexity - and expense - of sample return makes an international collaborative effort highly likely. ESA already is studying a pathfinder mission called NEXT that would test orbital rendezvous/docking and other technologies needed to make it work with the expected two-launcher approach.