Columbia Space Shuttle cockpit: 2 x HP-41C.

[Richard Garner]

I have read that not all of the software for the shuttle's de-orbit, re-entry and landing had been finished. Those calculation were programed into the HP 41C and run manually for the first half dozen flights. There is an HP 41C on display in the Air & Space Museum in DC that Sally Ride used on her fights. Until the HP 48GX came out the HP 41C was a standard tool on most shuttle missions.