HOUSTON — NASA announced Saturday that six astronauts have been selected for the Ares I mission, humanity's first crewed expedition to Mars, with a planned launch date in the spring of 2031 during the optimal planetary alignment window. The crew — four Americans, one European, and one Japanese astronaut — will spend approximately 30 days on the Martian surface before a return journey that NASA estimates will take seven months. The total mission duration is projected at 21 months, the longest crewed spaceflight ever attempted by a wide margin.
The mission architecture relies on a nuclear thermal propulsion system, developed jointly by NASA and the Department of Energy, that uses a nuclear reactor to superheat hydrogen propellant to temperatures far exceeding what chemical rockets can achieve. The result is roughly twice the fuel efficiency of conventional propulsion, cutting the Earth-to-Mars transit time from nine months to approximately five. NASA Administrator Dr. Camille Fogarty called the propulsion system "the single most important technological development in human spaceflight since the Saturn V."
The crew will travel in two vehicles: a transit habitat module called Hermes, where astronauts will live during the long transit phases, and a dedicated Martian descent and ascent vehicle called Ares Lander. The surface habitat, which will be delivered to Mars ahead of the crew by an uncrewed cargo mission in 2029, has already been partially built and is undergoing testing at the Johnson Space Center. It is designed to be partially buried under Martian regolith to provide radiation shielding — one of the primary health hazards of extended stays on a planet without a meaningful magnetic field.
The crew was named at a press conference attended by all six astronauts and broadcast live across NASA's digital platforms. Commander Elena Vasquez, a veteran of three International Space Station missions and a former Air Force test pilot, will lead the mission. She was joined by mission specialists Dr. Tarou Ishikawa, a geologist and astrobiologist; Dr. Priya Sundaram, a physician and surgeon; pilot Marcus Cole; systems engineer Yuki Brennan; and European Space Agency astronaut Lars Hofmann, who will serve as the mission's primary data and communications officer.
The primary scientific objective of Ares I is to search for evidence of past or present microbial life in the Hellas Basin, a vast impact crater in Mars's southern hemisphere where ancient hydrothermal systems may have once provided conditions hospitable to life. The crew will drill up to ten meters below the surface in several locations, collecting samples that will be returned to Earth for analysis. Scientists say the Hellas Basin location, while less studied than the Jezero Crater visited by the Perseverance rover, offers geological diversity that could dramatically expand our understanding of Mars's history.
The mission has a total budget of $87 billion over the program's lifespan, making it the most expensive scientific undertaking in NASA's history. That figure has drawn criticism from some legislators and scientists who argue the money could fund dozens of robotic missions at a fraction of the cost. Supporters counter that the strategic, psychological, and scientific value of human presence on another planet cannot be replicated by any number of rovers. "Robots are our scouts," Commander Vasquez said Saturday. "Eventually, you send the scientist."