ORNL said NASA and its partners began using NASA’s FUND3D software on supercomputers at the Department of Energy’s Oak Ridge Leadership Computing Facility (OLCF) to test simulations of a “human-scale Mars lander” in 2019 . In previous missions, parachutes were used, but ORNL explained that sending astronauts to Mars will require a much larger spacecraft and, paired with the planet’s thin atmosphere, a parachute would not provide enough support .