The document discusses HI-SEAS, a habitat located on Mauna Loa, Hawaii that is used to simulate long duration space missions on Mars. It provides an environment for testing astronaut crews in isolation for 4+ months and allows researchers to control mission parameters like communications latency. The habitat can accommodate 6 crew members and includes a laboratory and space for field work. When not in use for simulations, the portable habitat is available for education and outreach in the local community. The organization is now seeking crew for three back-to-back missions of 4, 8, and 12 months to study crew psychology and performance on long duration space exploration missions.