NASA hopes to send astronauts to Mars in the 2030s; here's how they will get there

NASA is readying to send astronauts to Mars by the 2030s and the agency's first, yearlong simulated mission took one giant leap toward making that goal a reality.

Marking the first completed installment of three planned programs from NASA's Crew Health and Performance Exploration Analog (CHAPEA), four crew members recently emerged from a simulated habitat at the Johnson Space Center in Houston, Texas.

The volunteer crew members logged 378 days in the 1,700-square-foot, 3D-printed habitat called Mars Dune Alpha, which simulated what a real-life mission to the Red Planet would entail.

Kelly Haston, Anca Selariu, Ross Brockwell and Nathan Jones entered the habitat on June 25, 2023, and completed the program this week on July 6.

"This was an incredibly successful mission," Dr. Suzanne Bell, lead of the behavioral health and performance laboratory at NASA Johnson Space Center and co-investigator on the CHAPEA project, told ABC News.

Bell explained that the program has been "monumental" in NASA's efforts to send astronauts to Mars in the coming decades by testing how humans can live, research, eat and sleep in a resource-restricted environment for such a prolonged amount of time.

The mission is designed to mimic what researchers would expect of a Mars mission, according to Bell, who noted the "incredible amounts of data" from the experience proved it to be a success.

Simulated spacewalks, robotic operations, habitat maintenance, exercise and crop growth were among the crew members' daily activities during the mission.

"Mars is our goal," Stephen Koerner, deputy director of NASA's Johnson Space Center, said during the press conference Saturday when the crew members emerged. "As global interests and capabilities in space exploration continue to expand, America is poised to lead," he said, adding, "The completion of the CHAPEA-1 mission is an important step in this goal."

So what would a human-led mission to Mars entail? Bell explained that the 378 days the crews logged in the simulated habitat was a design reference mission for the amount of time an astronaut crew would spend on the Martian surface.

"That length of time and the entire mission was built along this idea of trying to replicate, as best we could, what it would be like to have a Mars surface habitat mission," Bell said.

The transit period to get to Mars is approximately nine months each way, according to Bell, and the astronauts would spend over a year on the planet collecting data and assessing the planetary alignment that would allow the spacecraft to land and depart from Mars on the same orbit.

Likening the orbit to a coin donation funnel, Bell explained that the spacecraft would go into an oblong orbit and intersect with Mars to descend to the surface in a circle instead of only using fuel to get there.

Going to Mars and back will log more than a billion miles on the spacecraft's odometer, according to NASA, which is more than a thousand times the distance that Orion, the Artemis I spacecraft orbiting the moon, traveled.

Missions to Mars have higher energy needs, demand much longer system service life and have stricter departure timeframe constraints than moon missions, according to the agency.

Looking to the future, NASA's next CHAPEA mission is slated for spring 2025, and the third is expected to begin in 2026.

"Completing the CHAPEA mission was really exciting, and we are just thrilled at the success of the mission," Bell said, adding, "That's going to enable us to plan for the future, to compare it to other crews and position us to be able to someday land on Mars."