Selection and Observability Tests of GOPEX Reference Stars

Reference stars that can be used for calibration of telescope pointing in the GOPEX (Galileo OPtical communications with an Earth-based Xmitter) deep-space optical communications demonstration are selected. Observations of similar stars were conducted to test how easily the reference stars will be observed under the conditions to be encountered during GOPEX. It is concluded that the planned technique of observing the stars by eye through the telescope may not be adequate, and some alternative strategies are suggested.