Orbits of space stations and crew vehicles

[apace]

For reference:
Salyut 1: Apogee 222km, Inclination: 51.6
Salyut 4: Apogee 270km, Inclination: 51.6
Mir: Apogee 374km, Inclination: 51.6
Skylab: Apogee 442km, Inclination: 50.0
Tiangong 1: Apogee 362km, Inclination: 42.0
ISS: Apogee 398km, Inclination: 51.6

I know, inclination is chosen by the launch pads which needs to reach the orbital stations. But about the height of the orbit I'm a little bit confused. Are the orbits chosen by safety, by mission design or the visiting vehicles? Which heights current and future vehicles can reach?

Is there any possibility, that the chinese decide to go with Tiangong 2 or 3 to much higher orbit? Can this orbits be reached by a Shenzou spacecraft?

Greetings,
Daniel

[Archibald]

I never understood in the first place why was Skylab orbiting so high... 

[Jim]

I never understood in the first place why was Skylab orbiting so high... 

It had no propulsion, so it couldn't reboost.
Also, it set up a repeating orbit so that it would pass over the same points on earth every few days

[Jim]

. Are the orbits chosen by safety, by mission design or the visiting vehicles?

yes, yes and yes

[apace]

. Are the orbits chosen by safety, by mission design or the visiting vehicles?

yes, yes and yes

Thanks. Can I find somewhere information about the max orbits a visiting vehicle can reach?

For Space Shuttle I have: 190 to 960km
For Soyuz TMA I have: up to 460km

[Paper Kosmonaut]

[...]
Thanks. Can I find somewhere information about the max orbits a visiting vehicle can reach?

For Space Shuttle I have: 190 to 960km
For Soyuz TMA I have: up to 460km

960 KM? I think that is a wrongly assumed number. It would be a highly elliptical orbit, then - and only in theory.
Shuttles usually stayed far under 500 km. The highest orbit a shuttle ever flew was around 575 km when deploying Hubble in its orbit. And that was an elliptical orbit, too.
(please correct me if I'm wrong..)

[Jorge]

[...]
Thanks. Can I find somewhere information about the max orbits a visiting vehicle can reach?

For Space Shuttle I have: 190 to 960km
For Soyuz TMA I have: up to 460km

960 KM? I think that is a wrongly assumed number. It would be a highly elliptical orbit, then - and only in theory.
Shuttles usually stayed far under 500 km. The highest orbit a shuttle ever flew was around 575 km when deploying Hubble in its orbit. And that was an elliptical orbit, too.
(please correct me if I'm wrong..)

Right, shuttle is around 600 km, Soyuz 425 km.

[RocketmanUS]

I never understood in the first place why was Skylab orbiting so high... 

It had no propulsion, so it couldn't reboost.
Also, it set up a repeating orbit so that it would pass over the same points on earth every few days

Didn't Skylab have TACS ( thruster attitude control system )?

http://mix.msfc.nasa.gov/abstracts.php?p=1300

Was it out of fuel, not enough fuel left, or never had enough for rebust ?
 

[Jim]

I never understood in the first place why was Skylab orbiting so high... 

It had no propulsion, so it couldn't reboost.
Also, it set up a repeating orbit so that it would pass over the same points on earth every few days

Didn't Skylab have TACS ( thruster attitude control system )?

http://mix.msfc.nasa.gov/abstracts.php?p=1300

Was it out of fuel, not enough fuel left, or never had enough for rebust ?
 

Keyword - attitude, not altitude.

[DMeader]

Skylab was reboosted by the departing Apollo CSM wasn't it?

[Jim]

Skylab was reboosted by the departing Apollo CSM wasn't it?

Only the orbit phasing was adjusted