Dennis Wingo: Mid afternoon 6-19-13. We almost had a catastrophe yesterday. These tapes sometimes shed large chunks of oxide and this happened on tape M-91, one of the Scotch tapes. We had been observing a lot of shedding of material and that had clogged up the vacuum system, which Ken cleaned out. However, there was a large chunk wedged between the control track head (which is a separate head used to read the servo information) and the tape guide. This disrupted the geometry of the tape and contributed to getting a short length of tape sliced in two. It also created a terrible head clog (which kills all the signal from the tape from a single head of the four).
Ken disassembled the head, found the foreign matter and removed it. He also had to re-align the control track head and use a strong solvent to remove the foreign matter from one of the head tips. We are back up and running as of this afternoon as I had to go to the DMV today and in California that takes forever.
We did two tapes yesterday before the problems and I am on one today right now. It is late in the day but we should be able to finish our Madrid Scotch tape captures before I head off on a short vacation to go backpacking in the high Sierras.
Official website of the Lunar Orbiter Image Recovery Project (LOIRP)