Golden coloured paper in Satellites

Clausius2

Maybe I'm not able to question about it in english. Hmmm... let's go.

Why are the satellites and their external structures like panels, covered with a golden coloured paper when they are assembled?. Don't laugh at me!. I really never knew the reason. Also, I have seen the research staff of aerospace laboratories being dressed like a surgeon. Why?

Why such isolation measures in assembling processes?

Thanks in advance

chroot

It's actually gold-infused mylar shielding. It's the same sort of stuff that mylar baloons are made of, but with gold in place of aluminum. The main purpose of the gold foil is to reflect sunlight in order to keep the spacecraft from heating up. It also serves as a rudimentary micrometeoroid shield.

- Warren

chroot

Oh, as to your second question: clean rooms are used to prevent contimation of the spacecraft components by dust, hair, natural fibers, fingerprints, etc. It's essentially just a precautionary measure. You don't want to spend millions of dollars launching your satellite only to find out there's a fingerprint on a mirror or a piece of hair snagging a motor.

- Warren

LURCH

Have you ever seen the people that make computer chips? They dress the same way, and for the same reason. It is to protect the very delicate, sensitive components of the satellite from contamination. Any little bit of dust or moisture (from breath) or microscopic bits of lint from clothing could do serious damage to some systems.

The problem is especially bad when the satelite is being sent to capture and analyze samples, such as rock and soil samples for the Martian Rovers, or samples of solar wind from the Genesis probe. Such probes must be very clean and before they start their collections. If a tiny bit of dried skin or a stray eyelash get into the Mars probes, it would send back readings that positively identify living tissue on the planet!

enigma

What Warren said is correct. The stuff is called MLI for multi-layer insulation. In addition to the two purposes he mentioned it also acts as a shield protecting vulnerable metals from degradation by monatomic oxygen which is present in the ionosphere.

Clausius2

Thanks Warren, Lurch and Enigma. I've chosen to quote Lurch:

I've seen too some aircraft mechanics working on a F-16 in EADS, and they do not dress in the same way. The F-16 has high delicate electronic components, hasn't it?. Why dust or moisture can damage the systems you talked about? If I take up a transistor and breath near it, it works in the same way than before. About the panels and fingerprints, I understand how embarrassing would be that, Warren .

chroot

It would not be possible to service an F-16 in a cleanroom. The F-16 is already very very dirty from use by the time the aircraft mechanics work on it. To clean it up to cleanroom standards, before even beginning the repairs, would be unduly costly.

- Warren

Gonzolo

F-16's run on petroleum, which seems to be somewhat incompatible with anything "clean".

On a side note, the face shields astronauts wear on space walks holds a thin gold film (most likely along many other various coatings). It helps protect the face and eyes from solar and cosmic radiation.