Tethered Satellite, by one vote over working with the Russkies. Guess I should write about that one anyway, on another day.
Tethered Satellite was a joint project between NASA and the Italian Space Agency, Agenzia Spaziale Italiana. I was involved with the tether testing when I was a co-op student, which led to the choice of a copper conducting wire coated with Teflon, surrounded by Kevlar strength fibers and a Nomex overweave. This is what got me hooked on materials testing – from that point on, I picked classes that I thought would help in a future career at NASA and hung on through the weedout courses.
Skip forward to early 1992. One problem with the original coating on the satellite was that it wasn’t all that conductive in vacuum. When they had run the required tests, the paint had only been in vacuum for a few hours, so everything looked fine. What I heard was that someone left the coating in the vacuum chamber over the Christmas holidays and came back to find it nearly insulative. Houston, we have a problem.
One of the smarter coatings experts said that he could make a conductive coating that would work. We must not delay the shuttle launch. So they shipped the Tethered Satellite backup panels to us, we stripped off the old paint, applied the new paint, while running the qualification and acceptance tests at the same time. This meant manufacturing fixtures to hold the panels so paint could be applied evenly, because there was no time to ship them from Italy. This meant making sure the coating was indeed conductive in vacuum by testing in a simulated plasma environment, same as if it were in low Earth orbit, moving through the Earth’s magnetic field. It also meant all the other tests to make sure it would hold up in space – thermal cycling, atomic oxygen, ultraviolet radiation. It also couldn’t be a menace to the astronauts or to other experiments in the Space Shuttle, so there were flammability and outgassing tests. It had to be at least close in optical properties to the old coating, or we’d have had to re-run the thermal models.
We had eight days to do all that and not delay the launch. We did it in seven.
I was one of the wimps and only worked 16-hour days. (Mr. RFH remembers calling me and asking me if he was going to see me that day, and my reply was, “Only if you stay up until midnight.”) There were some people (the coating expert was one) that didn’t go home that week but caught a catnap here and there.
I can’t remember anything else quite like that effort, everyone working together for a common goal, and one of the very few times a daily meeting was necessary and productive.
We were so proud to see that fly, only to have the tether mechanism jam with the satellite only 853 ft. out. Dang it.