NASA Space Technology Report - Desert Research and Technology Studies (DRATS) 2009: A 14-Day Evaluation of the Space Exploration Vehicle Prototype in a Lunar Analog Environment

The Space Exploration Vehicle (SEV) concept is an integral part of NASA's plans for future human space exploration. Each SEV includes a small pressurized cabin to safely sustain two crewmembers for 14 to 28 days. Through suit ports, crewmembers may rapidly egress and ingress the cabin for extravehicular activities (EVAs). In addition to achieving a surface exploration range that is potentially orders of magnitude greater than was achievable during the Apollo Program, the SEV concept offers many other benefits, particularly with respect to the health, safety, and productivity of crewmembers during nominal and contingency operations.

The primary purpose of the 2009 Desert Research and Technology Studies (DRATS) test was to conduct a quantitative habitability and usability evaluation of the SEV 1B prototype during a high-fidelity simulation of a 14-day Constellation Program lunar mission. Although future exploration operations are expected to involve two SEVs, each with a two-person crew, the operations at DRATS 2009 focused primarily on operations by a single SEV with a two-person crew because only one mobile SEV prototype was available for testing. A two-person crew (Crew A) consisting of an astronaut and a field geologist remained within the SEV, day and night, for the entire 14-day mission, leaving the vehicle only through the suit ports to perform EVAs. Standard metrics were used to longitudinally quantify habitability and usability of all aspects of the SEV prototype throughout the 14-day mission. Vehicle and crewmember descriptive statistics were collected, including task times for EVA and intravehicular activity, distances traveled, scientific productivity, and egress and ingress durations. Multiple design modifications were identified, but the data indicated that the crewmembers found the overall SEV habitability and human factors to be acceptable for a 14-day mission. The SEV prototype was also found to be acceptable overall for 24 hours of habitation by four crewmembers, as assessed during a simulated crew rescue scenario on the final day of the 14-day mission.