OAO-2 was launched on 7 December 1968, and carried 11 ultraviolet telescopes.

Four astronomers on board will take turns operating Astro's three ultraviolet telescopes around the clock.

It contained a small optical telescope and a package of ultraviolet telescopes.

The first satellite, an ultraviolet telescope, was released eight hours after takeoff.

These observations were later matched with observations taken by orbiting ultraviolet telescopes.

If the observatory's three ultraviolet telescopes or one X-ray telescope point toward the Sun, their instruments could be damaged.

The four astronomers in the crew will use computers to operate the ultraviolet telescopes round the clock.

It has a 15-inch mirror and the largest field of view of any ultraviolet telescope ever built.

Astron's main instrument is an ultraviolet telescope developed jointly with the French.

It will investigate the shorter-wavelength radiation from the objects observed by the ultraviolet telescope.