Nancy Roman oversaw the development of the Orbiting Solar Observatory program from 1961 to 1963. The basic design of the entire series featured a rotating section, the "Wheel", to provide gyroscopic stability. A second section, the "Sail", was driven electrically against the Wheel's rotation, and stabilized to point at the Sun. The Sail carried pointed solar instruments, and also the array of solar photovoltaic cells which powered the spacecraft. The critical bearing between the Wheel and the Sail was a major feature of the design, as it had to operate smoothly for months in the hard vacuum of space without normal lubrication. It also carried both the power from the Sail and the data from the pointed solar instruments to the Wheel, where most of the spacecraft functions were located. Additional science instruments could also be located in the Wheel, generally looking out on a rotating radius vector which scanned the sky, and also across the Sun, every few seconds.
OSO 1 (OSO A) was launched on March 7, 1962.
OSO B suffered an incident during integration and checkout activities on April 14, 1964. The satellite was inside the Spin Test Facility at
Cape Canaveral attached to the third stage of its
Delta C booster when a technician accidentally ignited the booster through static electricity. The third-stage motor activated, launched itself and the satellite into the roof, and ricocheted into a corner of the facility until burning out. Three technicians were burned to death. The satellite, although damaged, was able to be repaired using a combination of prototype parts, spare flight parts and new components. It was launched ten months later on February 3, 1965 and was designated
OSO 2 (OSO B2) on orbit.
OSO 3 (OSO E1) was launched on March 8, 1967. == List of OSO telescopes ==