Six people
But I thought Soyuz was only rated for three.
Are they meant to sit in one another's laps for re-entry?
The crew of the International Space Station were obliged to take refuge in the docked Russian Soyuz capsule this afternoon, as space junk passed within 250 metres of the orbiting outpost. According to Interfax, a Russian space official described the temporary evacuation as "normal procedure" during a close encounter with …
The ISS orbits in the upper atmosphere, so the headwind quickly slows down and de-orbits all debris. This makes it a sort of "safe zone" (relatively).
The ISS itself will sink and deorbit within only half a year if abandoned, while smaller objects may come down faster due to having proportionally lower mass compared to their cross section... I think... Or am I thinking of surface area? Whichever.
For English, the plural would probably be "Soyuzes". You could write "Soyuzs", but it seems unnatural to me - the plural would add a third syllable, rather than an-awkward-for-English-speakers "zs" consonant cluster.
For Russian "Союз", it depends on which of the six cases you are using. See the drop down box in: http://en.wiktionary.org/wiki/союз
Something like "The ISS has two Soyuzes" would use the accusative plural "союзы". I think (but please correct me if I'm wrong) that your would you use the prepositional plural "союзах" for something like "The astronauts are in the Soyuzes".
Presumably the probability of an eventual collision is high. If / when one does happen, I expect it's likely to create a lot of debris that would make that orbit rather hazardous for a long while, even if the crew did manage to get away. Anyone got any info / factual on this?
No; this low altitude orbit was chosen partially because there's enough atmospheric wind drag to deorbit debris within a very short period, under half a year.
The flip side is that if the ISS is abandoned, it will come down in that timeframe.
Depending on the state of ISS after collision, it may be possible to remotely instruct it to accelerate, raising it above the debris field and should buy enough time (before it falls) to schedule more boost missions while a repair plan is conjured up.
It would be a problem for the upcoming final shuttle mission, though.
If a small centimeter size piece whizzes at the station at orbital velocities what will happen?
Will it shatter the station and cause it to spread even more debris about?
Or would it basically compromise the integrity of it, rendering it unfit for humans and knock it out of orbit without too much debris slapping out?
Any physicists / space structural engineers in the room?
Centimetre sized? Not unless it was travelling at relativistic rather than orbital velocities. And even then... a station module can be envisaged as a large, expensive Whipple shield. Might end up with a hole in one side and a lot of broken equipment in the middle but nothing much else if hit by tiny bits of debris. You'd lose pressure, of course.
Not sure how big something would have to be in order to be a serious threat to the integrity of the station rather than merely an expensive hazard.
There is no "orbital velocity" here; the more similar the orbits are, the lower the collision velocity. In principle it could only be a few hundred mph, or dozen, or a few. Conversely, something in a retrograde orbit would hit at around 15 km/s. Or much more.
So anything from a slight bump to blowing a large chunk of it to pieces, depending on the impact velocity and mass of impactor.
In short; get in the lifeboat, be ready to bail and find out what happens.