To rebuild the spare ISS PD Array unit (D1101059 S1202967, note that I myself don't have an access right for the S-number document on DCC) and align the PDs, we opened the transport container (D1400368) in the optics lab.
We initially had a hard time to open the container as the viton gasket (D1400366) was REALLY firmly stuck to the container lid (D1400367) and the container base (D1400365). We put the container on top of small stainless steel cart and used screwdrivers to pry the cover off from the base plate. Even after two corners were freed, we could not lift the lid just by hand, and we had to continue prying the lid until all four corners were freed.
Contamination:
After finally removing the lid, we found two bases for concern, the first is the contamination.
- There were some class A hardwares (screws/bolts, washers, one half of the QPD PCB retainer, and what turned out to be one of the two adjustment cams for one of the two plate high reflectors) scattered around on the transport container base plate, which is supposed to be a class B surface. But the base plate was dirty when we wiped it using pre-soaked wipe.
- Another half of the QPD PCB retainer was freely lying on the ISS PD base plate (D1300323) which is supposed to be class A surface, and it was dirty too.
- We wiped all parts that were not attached to anything, and they were all dirty.
- We haven't assessed the quality of the diodes nor the plate optics but there's no reason to believe that they are not contaminated.
The first two pictures shows the container assembly before and after removing the lid.
Note that the second picture shows the class A "cover" for the assembly tilted back. It turns that the cover was just put there, free to rattle. Connection rods that are supposed to attach the cover to the cage structure were not bolted to the cage.
The third picture shows how filthy the container base plate was. It also shows a half of QPD retainer parts that were found there, next to a swagelock fitting attached to the base plate.
Fourth picture shows the pre-soaked wipe I used to lightly clean the top surface of the PD array base plate. I immediately picked up some black stuff. You can also see that the PEEK parts are covered with black stuff.
Fifth picture shows the PEEK parts. I wiped the top parts but the bottom one is yet to be cleaned. You can easily see the difference.
6th and 7th picture shows deep scuff on the class A surface of the array PD structure, which seemed to have most accumulated the black stuff.
Glass chipping
We also found what seemed like tiny pieces of glass on the container base plate as well as the ISS PD base plate.
We inspected plate optics and found that all of them have chips. The worst one is one of the high reflectors.
The first three pictures show the damage of the leftmost HR optic seen from the beam entry point (i.e. array PDs are facing you). There appears to be a big chip where the adjustment cam is supposed to touch, but the cam was found detatched from the assembly and was on the transport container base plate.
The fourth picture shows the chip at the corner of the middle optic (BS). It also highlights that what seems to be the deep scuff marks or maybe grinding marks from the manufacturing process on the high reflector to the left (which is a different optics from the first three pictures as you're looking at the assembly from the array PD position so to speak) seem to have accumulated black stuff. That optic also has bad chipping on the front edge, which is more clear on the fifth picture.
The 6th picture shows one of the bigger glass pieces found on the surface of the transport container base plate. Note the black smudge on the glass (if it is glass).
