NASA can’t get two screws out…

[Cujet]

Its always the last 2 maybe they should try putting the screws on either side of the stuck ones back in to see if it take the strain off them.

That's probably correct. If they didn't loosen all of them evenly, those two likely have a lot of load on them.

 

[spasm3]

What is the mechanism behind cold welding? never been in space, nor a space buff, so I’ve not heard of this. Dissimilar metal reaction, yes, but not this.

https://en.m.wikipedia.org/wiki/Cold_welding

 

[Cujet]

Torque set head recess screws…

https://www.phillips-screw.com/drive_systems/torq-set/

Correct. We use them everywhere.

 

[spasm3]

 

[supton]

https://en.m.wikipedia.org/wiki/Cold_welding

Thanks. I had heard of something similar for wire wrap (and that is mentioned), but that isn’t done in a vacuum. Perhaps vacuum accelerates it, or helps, or isn’t a factor.

That must explain why all the bolts on my car are stupid tight after the dealership works on it, they never use anti seize and thus the metals don’t “know” they are separate.

The reason for this unexpected behavior is that when the atoms in contact are all of the same kind, there is no way for the atoms to "know" that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin surface layers of contaminants in between, the atoms "know" when they are not on the same part.

— Richard Feynman, The Feynman Lectures on Physics, 12–5 Friction

 

[ms21043]

Those are probably #10 torq set screws, very common on Airbus aircraft. They are available in titanium, which these probably are. Thing with titanium screws is when they sieze, you're screwed lol.
If they can't drill the screws, due to contamination, or if they can't use a 'Johnson bar' screw extractor, or similar for whatever reason, then Houston we have a problem.

 

[mk378]

Anything that has been in space for a long time is likely to seize up. They should have expected this and designed the screw heads to break away under moderate torque if the screw is stuck. It's a one-time use machine.

 

[Kira]

From the linked article: "NASA scientists successfully brought an asteroid sample back to Earth in September, making them the first U.S. space agency to do so."

So........NASA and the Space Force are in administrative competition already? See you at the allocation meeting. (ha-ha)

Also: The , "semi-automated focus stacking procedure". All to take a photo of a filter...a filter assembly which appears could be held in your hand?
I wonder if said 'focusing procedure' is used for extreme quality photos of the dust before handling and not applicable to the included picture.

edit: Just had a thought. That ring of screws has to weigh something. What became of eliminating fasteners at all costs? (ha-ha)
I'd love to listen to the design team describe the attributes of that assembly.
You gotta admit, the 'mylar flap' sure sounds like a one-way valve...much like an ADBV (flap).

 

[mattwithcats]

NASA finally gets the two screws out…!

https://www.aol.com/news/nasa-finally-figures-open-1-110037389.html

 

[Pablo]

https://pbs.twimg.com/media/GEOTwkEXcAAc_qO?format=jpg&name=large

 

[supton]

Was going to respond with the article link I saw too, but appears I got beat.

...the team designed custom tools made from a specific grade of surgical, non-magnetic stainless steel to pry it open – all without the samples being contaminated by Earthly air.

 

[Pablo]

Was going to respond with the article link I saw too, but appears I got beat.

I worked on the propulsion way back when!

 

[Aredeeem]

As a klutz DIY who has spent a lifetime screwing up the simplest projects I’m enjoying this immensely. All the while I thought it was ‘ Just me.’