One a clear dark night it is quite easy to spot a few satellites in the sky.
Can the space station crew see them above or below their orbit ?
What about the space shuttle crew ?
Below, not a lot; the ISS orbits at an altitude of 420 kilometres, and there aren’t very many satellites lower than that (although Starlink is planning to have part of its constellation at “very low Earth orbit” altitudes of 300-400 kilometres). Above, yes, and I would think the views from the ISS up are now dominated by the around 2,000 Starlink satellites that have already been deployed. (Much) further up there is the geostationary orbit at about 36,000 kilometres. Note, however, that the higher the orbit of a satellite or space station, the longer it will take for one revolution; so it’s not so much the crew of the ISS seeing satellites circle above it but rather the crew seeing how their station overtakes the slower satellites.
Not as far up are the navigation constellations. GPS and (I think) three others. They’re around 20,000 km give or take a couple thousand. Not sure if these are visible from ISS and for that matter, I’m not sure if the various com satellites at geostationary are visible either.
I don’t think any geosynchronous satellites are visible to the naked eye from Earth (nor from the ISS, which on these scales, is basically on the Earth).
In terms of distance, yes, but there are other factors that could affect the viewing.
First, on Earth, you’re looking through at least one thickness of the atmosphere, possibly as many as two, if the satellite is low on the horizon. That’s not a problem on the ISS.
Second is light pollution which is variable on Earth. If you can get to a dark site, it’s great; inside most cities, it’s a big problem. On the station, to avoid it you would have to block off internal station lights and find a view which does not have any external sunlit parts of the station. Or block those off too. Then let your eyes adjust to the dark view, which could take many minutes. But even if you did all that, you are unlikely to see any geostationary satellites with the naked eye. But your view of the stars will be first rate.
In theory that all works but the ISS isn’t an observation car on a train. How easy is it to look thru the portholes on the ISS? Are they too thick or tempered to allow viewing of things at great distances like that?
Let’s say TPTB approve a space walk with the sole intended purpose of looking at satellites / stars; same question about the space suit visor/face shield. Are they tinted like sunglasses? Does the curvature make seeing things at that distance difficult?
Allowing for engineering overkill, they’re likely to be able to contain around 3 or 4 atmospheres. They don’t have to be super thick for that. It’s not like they’re going down to the Marianas Trench.
Somewhere I read that astronauts complained about not having enough free time. One of the things they wanted to do on that free time was just look out the window at the Earth. Sounds like there’s at least one decent viewing window.
There is a structure explicitly intended for viewing. The Cupola.
If you are only worried about managing the pressure inside the ISS, the engineering is no worse than any commercial jet-liner. However jets don’t have to content with hyper velocity impacts from tiny bits of dust. So windows, and indeed the entire ISS are engineered somewhat differently. Jet cockpit windows are perhaps a middle level of the engineering needed. They need to manage bird strikes.
Fry: How many atmospheres can the ship withstand?
Farnsworth: Well, it’s a spaceship, so I’d say anywhere between zero and one.
Yes, but there’s the engineering safety factor. Most engineers aren’t happy without a factor of at least 3.
At any rate, Francis makes the good point that micrometeoroids are a more important issue for station windows. If those windows in the Cupola didn’t have external shutters, the windows would eventually become useless for looking out of. Not sure exactly what timeframe that would be, but soon enough. Reading about the Cupola, I find they made the windows able to be replaced in situ, which means they were concerned about this issue.