ISS Questions from a Newcomer - can anyone help?

[EAK09]

Greetings -- this is my first time here since 1999. Impressive community here. I was hoping that some/any of you might be able to point me to some educational resources. I was involved with Aerospace a couple of careers ago, but discovering a NASA cable television program reminded me how much I miss the topics I grew up dreaming of. Thanks in advance for tolerating some potentially silly-sounding questions (I had a list of about 12).

Here was my first question.
Can anyone answer...

Progress vs. Soyuz -- what's the difference?
I'm assuming these are one and the same, only with and without crew vs. cargo.
I'd aslo venture that progress craft lack reentery heat shields?

Thank you.

 

[3488]

Hi EAK09

Welcome to SDC.

That is NOT a silly question, far from it.

Yes you are broadly correct. A Progress is a Soyuz type craft with no heatshield.

A couple of links below.
Progress Vehicle.

Soyuz Vehicle.

Andrew Brown.

 

[EAK09]

Hi EAK09

Welcome to SDC.

That is NOT a silly question, far from it.

Yes you are broadly correct. A Progress is a Soyuz type craft with no heatshield.

A couple of links below.
Progress Vehicle.

Soyuz Vehicle.

Andrew Brown.

Hi EAK09

Welcome to SDC.

That is NOT a silly question, far from it.
Yes you are broadly correct. A Progress is a Soyuz type craft with no heatshield.
Andrew Brown.

Thank you.
I'll read up.
I'm curious -- do you know how ISS crew ever use these while docked?

In particular...

More Room! -- I could imagine crew taking dibs on who got to use the next progress/soyuz as their private quarters.
In the interest of having more room as often as possible, I would imagine that crew would want all available docs to have progress/soyuz craft connected to them.

Trash... I understand that progress/soyuz are periodically sent back to burn up in earth's atomosphere laden with trash. I wonder, what dictates what trash reenters this way versus being directly jettisoned (I assume they do that too?).

ISS crew supply requirements -- what are they?
Is it a fair assumption that 6 crew members consume approximately one progress mission worth of supplies every 2 months or so? (progress/ESA version/HTV version).

Why two days to reach ISS?
I'd imagine that if progress (or shuttle) craft were launched at any random time, it could take up to two days to redezvous with ISS. On the other hand, if there are actually "launch windows" for this, I'm surprised that it takes about two full (?) days to reach ISS orbit.

 

[trailrider]

Welcome back! There are probably others who can explain this more thoroughly and giving the exact technical facts, but in general, you could probably launch a Soyuz or Progress directly to the ISS in a few minutes, or at least under an hour, but... you would expend a lot more fuel (maybe more than the Soyuz booster is capable of holding), and you would have to launch almost exactly on the second, when the ISS was just in the right point of its orbit.

You still have to launch within "windows" of time and position for both the ISS and the Soyuz/Progress in order to be close in terms of the coincidence of the planes of orbits of the two, as well as the relative positions of the two along their orbits. But you can make use of orbital mechanics (Kepler's Laws), to rendezvous with an economy of propellant expenditure. Maybe when we get propulsion systems that have high-thrust and high specific impluse (liquid unobtanium/and liquid nonesuchium) we'll be able to "cut the corners". Meanwhile, it'll just have to do the 2-days to rendezvous thing!

Ad LEO! Ad Luna! Ad Ares! Ad Astra!

 

[StrandedonEarthsince1970]

After reading up on the Progress, you would think it would be worthwhile to put a minimal heatshield and 'chutes on the tankage module, which would be the descent module on the Soyuz. The tanks could be recovered and reused. But I guess that would reduce the payload too much.