Astro (ass -troh) An astrophysics mission launched by NASA in Dec. 1990 and operated for about 10 days from the bay of the space shuttle. The payload consisted of four instruments. The Wisconsin ultraviolet photopolarimeter experiment (WUPPE) provided polarization studies in the UV spectral region of 140–330 nm. The Hopkins ultraviolet telescope (HUT) made spectroscopic observations in the far-UV and extreme-UV wavebands. The ultraviolet imaging telescope (UIT), providing a 2″ resolution over a wide (40′) field of view, obtained many hundreds of UV images of a wide range of sources. The broad-band X-ray telescope (BBXRT) provided X-ray spectra of sources in the energy range 0.3–12 keV with an energy resolution of about 100 keV. The payload was returned to Earth after the mission. A second mission, Astro-2, was completed successfully in 1995.