Spaceflight

Commercial Orbital Trans­port­ation Services (COTS) could play a role in manned Mars missions by providing low-Earth orbit (LEO) fuel depots for Ares V-launched Earth departure stages (EDS) to become Mars transit vehicles (MTV).

Under current plans for Moon missions, beginning by 2020, the EDS will use half of its fuel to boost its lunar lander payload into LEO.

"If you refilled the EDS in orbit [using commercial LEO fuel depots] it could act as the MTV," says Georgia Institute of Technology aerospace professor Douglas Stanley, manager of the November 2005 NASA exploration systems architecture study (ESAS).

ESAS used NASA's own 1998 Mars design reference mission in its analysis, and conclusions reached by Stanley's study included the proposed 25t-payload crew launch and 125t cargo launch vehicles, now adopted by NASA as Ares I and Ares V.

NASA
The 125t to LEO Ares V could play a crucial role in Mars missions

On 3 August at the International Mars Society convention NASA administrator Michael Griffin said the agency would study Mars missions in 2007. This is likely to build on the ESAS Mars analysis, as any future mission would use the Ares I and Ares V.

A January 2005 internal NASA presentation identifies the need for an 80t-plus payload launch vehicle to construct a 467t, solar electric-propelled Mars-ship for a 1,000-day mission.

Blog:
Read Rob Coppinger's view on the latest NASA manned mission to Mars study