STS-41-C launched on April 6, 1984. The mission marked the first direct ascent trajectory for the Space Shuttle; Challenger reached its 288-nautical-mile-(533-km)-high orbit using its Orbiter Maneuvering System (OMS) engines only once, to circularize its orbit. During the ascent phase, the main computer in Mission Control failed, as did the backup computer. For about an hour, the controllers had no data on the orbiter
