This question is related to reuse possibilities. One of the things that affects reuse is thermal cycling of the fuel tanks. (Consider how microfractures in the X-33 composite tank killed that project. Ok, political lack of will killed it, but that was the excuse).
Thus the question. With the DSCOVR Falcon 9 launch, Feb. 2015, we saw the core do the following fuel/defuel events:
- McGregor testing: 1 fuel/burn it out. (We know they are all tested with a burn at Texas site)
- Wet dress rehearsal: 1 fuel/defuel, 1-3 second burn.
- First attempt, Feb. 8: 1 fuel/defuel
- Second attempt, Feb. 10: 1 fuel/defuel
- Third attempt, Feb. 11: 1 fuel (hopefully 1 launch, recovery, and eventually reuse).
Which F9 core has done the most of these cycles? There have been lots of scrubs, delays, tests, failed wet rehearsals, etc.