Sometime between leaving the cartridge test stand and yesterday inside of BSC10, the optics in the suspension got really dirty. The barrels of the ETM test mass, ERM optic, and PUM have accumulated alot of particulate. I wiped these clean just prior to welding in Jan and recall them looking much better than they do in the pictures below when they were hanging on the test stand. So, between the last bit of cartridge work, the cartridge flight and the in-chamber work over the last week lots of particulate has swirled around the in-vac hardware (about a 2 week duration). Here's the sequence of cleaning in case Calum wants to know:
On test stand, just prior to flight:
- I wiped and vacuumed SUS, bagged both SUS and TMS
- Hugh wiped all of the ISI above, then bagged ISI
Cartridge flight Feb 24th
~2 days after in-chamber I wiped entire floor and viewport surfaces of BSC10 chamber, I did NOT inspect optics
- cabling, TMS payloading, SEI float/balance
- yesterday, I see this gross particulate accumulation, some on the suspension structure too, harder to see since it's metal surfaces though
- I wipe the entire floor of chamber again
More cleaning to follow, obviously.
Note, the particle counter which was hanging around in the test stand area was worked on early last week and then parked under the tube in the chamber cleanroom. This wasn't a particularly useful place to count particles so I moved the counter to in front of the door yesterday. Long story short, no particle data is useful before yesterday. Par.