ts work completed, it would then separate, aerobrake in Earth’s atmosphere, and return to the Station for reuse. The second OTV would repeat this performance, then the piloted sprint spacecraft would burn nearly all of its propellants to place itself on course for Mars.
The piloted spacecraft would aerobrake in Mars’s atmosphere and fire its engines to circularize its orbit on 3 June 2005. Almost immediately after MOI, the crew would rendezvous with the waiting cargo spacecraft. Three crewmembers would board the Mars Lander, deorbit, and land at the preselected landing site. They would explore the site for from 10 to 20 days. The other three astronauts, meanwhile, would transfer the Earth-return propellants stored on board the cargo spacecraft to the piloted spacecraft’s empty tanks. They would also discard the piloted spacecraft’s MOI aerobrake.
SAIC noted that the ideal trajectory for a one-year piloted Mars mission launched as soon as possible after the arrival at Mars of the cargo spacecraft on 29 December 2003, would have the piloted spacecraft depart Earth on 8 January 2005, reach Mars on 2 August 2005, depart Mars on 1 September 2005, and return to Earth on 8 January 2006. SAIC’s Earth-departure date, a little more than a month ahead of the ideal date, would increase the piloted mission’s duration by almost two months.
Launching the piloted sprint spacecraft early would, however, add an abort option to the mission. If, for example, the cargo spacecraft’s propellant cooling system failed and allowed the Earth-return propellants to escape while the astronauts were en route to Mars, then they could use the propellants that they would have used to circularize their orbit about Mars after aerobraking to ensure that their spacecraft would skim through Mars’s uppermost atmosphere on 3 July 2005. The aeromaneuver, properly executed, would nudge the piloted spacecraft’s course enough that it would intersect Earth on 15 January 2006.
SAIC explained that one goal of Phase II of the Mars program would be to seek out a site for a permanent Mars base. The company envisioned that NASA would launch a series of three split/sprint missions by the end of the first decade of the 21st century. In fact, while the first crew explored Mars’s surface and worked in orbit to prepare their spacecraft for the trip home, the cargo spacecraft for the second Mars crew would depart LEO boosted by the same large aerobraking OTV the first mission’s cargo and piloted spacecraft had used. The second crew would leave Earth orbit in early 2007 and return from Mars in early 2008. The final crew in the series would depart for Mars in early 2009 and return home in early 2010. After that, establishment of the Mars base – Phase III of SAIC’s program – could begin. The company provided few details of Phase III.
With their surface mission completed, the first Mars explorers would lift off in their Mars Lander’s ascent stage. SAIC explained that the ascent stage would make up about half the mass of the Lander. The piloted spacecraft would rendezvous and dock with the ascent stage in Mars orbit to collect the surface crew and their Mars samples. On 2 August 2006, shortly after casting off the spent ascent stage, the astronauts would fire the piloted spacecraft’s twin engines to begin a five-month return to Earth.
Nearing Earth, the astronauts would enter the ERV capsule with their samples and separate from the crew spacecraft. The ERV, which would resemble one of the early designs for NASA’s planned Space Station lifeboat, would slide out of a radiation shield housing that would remain behind on the crew spacecraft. The abandoned sprint spacecraft would then fire its engines a final time to miss Earth and enter orbit about the Sun.
The ERV would aerobrake in Earth’s atmosphere, then an automated OMV from the Space Station would retrieve it. After physical examinations and a period of quarantine on board the Station, the first Mars crew would return to Earth on board a Space Shuttle.
SAIC wrote that its piloted split/sprint Mars mission could open the door to in