The original ROTSE-I had 4 telephoto lenses of 11 cm aperture, covering a 16x16 degree field of view. This detected the first afterglow of a GRB while the burst was still ongoing, but this was the only burst detected by ROTSE or the very similar Livermore Optical Transient Imaging System. Therefore, ROTSE-II was designed, also featuring a large field of view, but it was never built, since new satellites such as HETE-2 and SWIFT could provide smaller error boxes, making a huge field of view unnecessary.