In a leaked memo from NASA it has been revealed that the acronym agency really does make up acronyms to fit words they have already come up with, even when the word does not seem to resemble any aspect of the resulting acronym.
The "Medical Information Computer System" (MedICS) is not too bad, but "Determination of Orbit Radio positioning integrated from Shuttle" bears little resemblance to the acronym (DORIS), and nor does CHROMEX (Chromosome and plant cell division in space). After the Challenger disaster the "Approach/Landing Autopilot Subsystem" (ALAS) was changed to the "Automatic Landing Instrumental Approach Subsystem" (ALIAS), due to negative connotations.
Such negative connotations have meant that NASA have sometimes not taken the obvious acronym. The "Flight Unit Clock" is called FU, whilst the "Wide Area Network Knowledgebase" is called WANN. Some are missed, and the "Travelling Wave Amplification Tube" kept it's acronym, as did the "Super High Impact Test" and the "Final Approach Radio Telecom System".
Sometimes, even the Rocket Scientists fail, and the acronym ALERT proved a problem; in the end, "Acute Launch Emergency Restraint Tip" was chosen. On occasion they excel themselves though, and when an operator announces that they will be visiting the TAVERN, their supervisor will believe they are checking the "Test and Verification Environment for Remote Networks", when in fact they are off to get "Parts Instrumental for Space Shuttle External Doors".