The HP-65 was the first magnetic card programmable handheld scientific calculator. The Hewlett Packard Corporation introduced it in 1974. The HP-65 kit included a pack of narrow magnetic cards that could be inserted into a reader under the display screen to load or save programs. NASA chose the HP-65 for use on the Apollo-Soyuz Test Project flight in 1975, for which it was programmed with rendezvous and guidance equations as a backup in case the main Apollo Guidance Computer failed. This specimen may have been retained or acquired by NASA for later use, but by the time the Space Shuttle began flying in 1981, more advanced versions of this calculator were available.
NASA transferred this device to the Museum with a variety of crew equipment when the Space Shuttle program ended in 2012.