The ASTRO Observatory had three primary instruments: the Ultraviolet Imaging Telescope (UIT), the Hopkins Ultraviolet Telescope (HUT) and the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE). The Astro Observatory was designed to use many of the spacelab components and flew on two different shuttle flights. The first Astro flight was on December 2-11, 1990, aboard the shuttle Columbia. The X-ray experiment Broad Band X-Ray Telescope (BBXRT) was also part of the Astro-1 flight. The second flight was on March 2-18, 1995, aboard the shuttle Endeavour.

HUT obtained ultraviolet spectra of astronomical objects such as quasars, active galactic nuclei, and supernova remnants, extending into the little-explored ultraviolet range below 1200 Ångstroms. The instrument consisted of a telescope, prime focus spectrograph, and intensified photodiode array. Scientific studies have included research on the cores of active galaxies (where black holes likely reside), the torus of gas around Jupiter created by its moon Io, the characteristics of the intergalactic medium, and the stellar population in elliptical galaxies.

UIT consisted of a telescope and two image intensifiers with 70 mm film transports. The instrument acquired images of faint objects in broad ultraviolet bands in the wavelength range of 1200 to 3200 Ångstroms. Astronomers have investigated the present stellar content and history of star formation in galaxies, the nature of spiral structure, and non-thermal sources in galaxies using UIT data.

WUPPE obtained both ultraviolet spectra and polarimetry for celestial objects such as hot stars, galactic nuclei, and quasars. The instrument included a telescope, spectropolarimeter, and dual diode array detectors. Researchers have studied the interstellar medium, mass loss from hot stars, interacting binary stars, and active galaxies, among other topics.