FIGURE 4.1 Design Reference Architecture 5.0 Human Landing on Mars. SOURCE: NASA, Human Exploration of Mars Design Reference Architecture 5.0, 2009.
throughout the 700-day mission (except for the 2 months spent in Mars orbit). The in-space duration for this mission is more than 3 times that expected for the Mars surface mission, and deep-space habitation and logistics for a 700-day in-space mission may not be feasible, depending on the challenges of GCR.
188.8.131.52 Mars Surface
The horizon goal for human spaceflight is the human exploration of the Mars surface. Numerous concepts for surface exploration missions have been described in various documents; the analysis in this report is based on NASA’s Mars DRA 5.0. The mission is based on sending three different vehicles to Mars, as shown in Figure 4.1. Multiple SLS launches would be required to place both the cargo and crewed portions of the mission in LEO.
The cargo portion of the mission would use two vehicles to carry support equipment and travel to Mars during a planetary alignment before the crew transit.39 This would allow verification that the support equipment had arrived successfully and that the crew’s ascent vehicle has landed on Mars with sufficient time to use in-situ resources to produce propellant. The mission concept relies on the crew landing on Mars close to the predeployed ascent vehicle and its support equipment. The cargo missions would use a minimal-energy 350-day trajectory from Earth, and they would enter Mars orbit using aerocapture technology. One of the predeployed vehicles would then perform aero-assisted EDL and initiate preliminary robotic efforts to prepare the landing site for the crewed mission. The second predeployed vehicle would wait in Mars orbit for the arrival of the crewed vehicle.
39 Transit times and propulsion requirements for missions to Mars are minimized when Earth and Mars are favorably aligned in their orbits. Such alignment occurs every 26 months or so.