Not sure. An ariane 4 rocket exploded due to a leftover cleaning rag in a water line. I would guess the launcher + payload price would top the price of an F16?

It's got to be up there with the NOAA N-Prime (un)screwup:

http://www.nasa.gov/pdf/65776main_noaa_np_mishap.pdf

Not sure if knocking over a satellite is more or less expensive than totaling one F-16 and damaging another.

Surely there must be a checklist to follow before maintenance like this that involves either locking the fire buttons, unloading the ammunition or with some kind of reliable software switch.

Either possibility, that such a procedure is not followed, or that there is no such procedure, is worrying.

Yeah, for accidentally hitting a button... I wonder if that characterization is accurate. Cost would be up there with the economic cost of Hawaii’s accidental missle alarm button click.