OAO - friznit/Unofficial-BDB-Wiki GitHub Wiki

The Orbiting Astronomical Observatories (BDB Roman) provided the first high quality observations of space objects in ultraviolet light. OAO-1 was uniquely launched on Atlas-SLV3B. The Atlas SLV OAO-3 Copernicus telescope remained operational for nearly 10 years and its success led to the instigation of the Hubble space telescope.

Both OAO-1 and -2 have a secondary instrument package (the BDB "Smithson" telescope) on the bottom, whilst the OAO-3 replaces this with a service bay that can be filled with other experiments to taste. To build the SLV3B fairing, place the SLV3B Adapter section under the Agena upper stage, cancel the stock fairing on the adapter and then place the dedicated SLV3B fairing on top of it.