The conceptual basis of an orbiting observatory designed for high angular resolution optical astronomy is presented. Operating above the atmosphere, an array with a 15 meter baseline could achieve a one-dimensional angular resolution of 0.005 arc sec in the visible. Broad-band detection from the UV to the near infrared should be possible. To obtain two-dimensional images at high resolution we expect to employ tomographic reconstruction techniques, followed by sidelobe removal if necessary. Active optical elements will be needed in order to maintain coherence of beams in the image plane. The instrument is an optical analog to the Very Large Array in radio astronomy and a space analog to the Multiple Mirror Telescope. Prototype designs consisting of four to six mirrors are discussed for the case of a single shuttle payload.