Space Station windows impervious to abrasives?

[TristanVT]

Why aren’t the windows of the ISS (and the rest of our spacecraft) not frosted from the space dust? Microscopic particles (diamonds included) moving at thousands of miles per hour would eventually take their toll on even the most durable materials. What gives? Also, I had one of my questions published in the syndicated column. Where’s my T-shirt, dammit!?

[Squink]

I don’t think the ISS has been up there long enough to get its windows frosted. The shuttle fleet windows have taken some hits, but nothing approaching the levels needed to frost glass:

The Space Transportation System (STS) fleet has flown more than sixty missions over the fourteen years since its first flight. As a result of encounters with on-orbit particulates (space debris and micrometeoroids), 177 impact features (chips) have been found on the STS outer windows (through STS-65). Forty-five of the damages were large enough to warrant replacement of the window.

For picture: Shuttle Window Strike - STS-94

So the impact rate isn’t all that high. Plus, on the ISS they put shutters over the windows when they’re not looking out of them:

A typical window for a house on Earth has 2 panes of glass, each about 1/16 inch thick. In contrast, the ISS windows each have 4 panes of glass ranging from 1/2 to 1-1/4 inches thick. An exterior aluminum shutter provides extra protection when the windows are not in use.

[R.P.McMurphy]

Consider the concept of “space”. Yes, there is stuff out there but the concentration is miniscule to what is in the Earth’s atmosphere. An automobile windshield on Earth that will be noticabley affected by airborne abrasives is many multibles of what will occur in space.

Any space vehicle can be destroyed by a metiorite but because of the vastness of space the odds are very slim. That’s what make space travel inherantly safe.

[Stranger_On_A_Train]

@Spartydog

Any space vehicle can be destroyed by a metiorite but because of the vastness of space the odds are very slim. That’s what make space travel inherantly safe.

Actually, the odds aren’t that slim, and space travel is about as far from “inherently safe” as walking around with a bulging wallet in the French Quarter. One of the largest outrages regarding China’s recently tested ASAT capabilty is all the debris they’ve left in Low Earth Orbit, but quite frankly they aren’t the only ones, as the United States and the Soviet Union have both performed operations that have left hazardous space junk in orbit. (Then there’s that golf ball…you think these guys would learn that in orbit “What goes around comes around” isn’t just a metaphor.)

Reasonable protective measures (i.e. the afformentioned shutters) are taken, but there is a not insigificant hazard of collision with and damage by small debris. The likelyhood of impact may be relatively small, but the consequences of a significant impact are catastrophic, and it will happen sooner or later. (In fact, there are at least a couple of anomalous orbit insertion failures that are strongly suspected, though unproven, to be due to micrometeor impacts.)

Stranger