Three first-generation instruments, CASIMIR, SAFIRE, and AIRES were selected for SOFIA, but were halted at different stages of development.

In accordance with Policy 9 of the Science Utilization Policies for SOFIA, the NASA SMD Astrophysics Director Dr. Paul Hertz decided to retire the FLITECAM Facility-class Science Instrument, effective February 2018. The decision was also made to remove the Special-purpose Science Instrument HIPO from the list of SOFIA supported instruments. These two instruments will therefore not be offered in future calls, nor be available for DDT proposals.