The Explosive Transient Camera (ETC) is a wide field (-3isteradns) electronic camera array which can detect coincident optical flashes with durations of ~10 to 10 seconds. It is anticipated (but not yet conclusively demonstrated) that simultaneous optical flashes will be associated with certain classes of gamma ray bursts (GRBs). For the ETC, each array element is a 20° x 30° FOV, cooled CCD detector, developed at MIT. An optical transient as faint as B = +11 (1 second duration) can be detected with S/N > 20, and its position determined to an accuracy of + 10 arc seconds. Thus, candidate events ~10 times fainter than the archived event (plate taken in 1928) reported for the 19 November 1978 gamma ray burst (GRB) by Schaefer (1981) should be detectable in real time. In addition to detecting GRBs, the ETC is expected to catalog large numbers of flare stars, as well as potentially new classes of astronomical transients. The coordinates established by the ETC will be immediately transmitted (--1 second delay) to the Rapidly Moving Telescope (RMT) under development at NASA/GSFC (Teegarden, Cline and von Rosenvinge 1982), which can further refine the position of a flash and follow its (presumed) subsequent decline. Communications to other rapid response radio or IR instruments will also be provided for, as well as time comparisons to gamma ray events detected by the International GRB Satellite Network (Hurley 1981). A prototype camera element was first tested in April 1982 to establish sky background levels and spurious event rejection schemes. A 1/2 steradian test version of the ETC is planned for operation in early 1984. Expansion to the full 3 steradian complement of 16 detectors at each of two sites is planned during the 1984-1985 period.