NASA is planning to start development work for a manned Mars mission's Lander and its interplanetary Transfer Stage in the fourth quarter of 2009 as part of the agency's $125 million Propulsion and Cryogenics Advanced Development (PCAD) project.
According to a PCAD document obtained by Flight $5.8 million of the $125 million will be spent on "Mars propulsion technologies" for a Mars Lander and Transfer Stage. Initial development work is expected to begin in fiscal year 2010, which actually starts on 1 October 2009, with funding from October 2011, the start of fiscal year 2012. The $5.8 million is planned to be spent over FY2012 and FY2013.
This funding will be for "demonstrations and validation of engine performance levels" for engines on the "Mars Transfer Stage" and Lander descent and ascent stages. Under the 2007 Mars design reference architecture 5.0 NASA has been working on, the Lander would carry a crew to the surface as part of a 900-day mission to the red planet notionally launched in February 2031.
The PCAD document says: "The work will include a combination of experimental and analytical tasks. System and engine performance models will be developed, preliminary engine designs developed, individual risk reduction activities conducted and a first generation prototype engine developed."
According to the 5.0 architecture the Mars Lander would use an aerodynamic and powered descent method. This would likely use aerobraking, already proven with robotic Mars probes, for slowing the Lander initally at the uppermost reaches of the Martian atmosphere using a ballute for deceleration, followed by a series of parachutes and finally its descent module's propulsion system.
The Mars Transfer Stage and the Lander would be part of a 400,000kg (880,000lb) Marship that would be assembled in orbit using an Ares V cargo launch vehicle with a 10m (32.7ft) fairing. Capable of putting 125,000kg into low Earth orbit the Ares V would assemble the Marship with three or four launches.
Read about NASA's Mars mission planning and related Constellation Moon, Mars programme material at Flight technical reporter Rob Coppinger's Hyperbola blog
See images, not to be found on NASA's website, of the US space agency's Constellation vehicles that will send astronauts to the Moon and Mars at the airspace.aero Constellation gallery