The feasibility of performing an on-orbit refueling (OOR) operation to extend the orbital lifetime of the NASA Goddard Space Flight Center (GSFC) Gamma Ray Observatory (GRO) was investigated by TRW, the GRO mission contractor. This study shows that an OOR capability could be integrated into the GRO operational design early in the Phase D development with only minor cost impact and no schedule impact. In this approach, the GRO OOR design would be developed to achieve operational compatibility with the JSC/STS-developed Orbital Refueling System.
Donald A. Molgaard,
"Payload On-Orbit Refueling Using The Space Transportation System (STS)", Proc. SPIE 0493, Optical Platforms, (23 October 1984); doi: 10.1117/12.943791; https://doi.org/10.1117/12.943791