STS-61-A "Challenger" (October 30-November 6, 1985), was the West German D-1 Spacelab mission. It was the first to carry eight crew members, the largest to fly in space, and was also the first in which payload activities were controlled from outside the United States. More than 75 scientific experiments were completed in the areas of physiological sciences, materials science, biology, and navigation. During the flight, Dunbar was responsible for operating Spacelab and its subsystems and performing a variety of experiments. Her mission training included six months of experiment training in Germany, France, Switzerland, and The Netherlands. STS-61-A launched from the Kennedy Space Center, Florida, and returned to land at Edwards Air Force Base, California. Mission duration was 7 days, 44 minutes 51 seconds, traveling 2.5 million miles in 111 orbits of the Earth.