Roll of SAS, Other thrust in maintaining orbit

[Brok3n]

I've achieved orbit a few times with small satellites powered by a single ion engine. I'm now starting to look towards launching larger craft for making a space station. I've been reviewing a number of guides but I still have a few questions.

1. does a space station need thrust, like a liquid engine with fuel to maintain orbit? Is there an advised engine with fuel tank I should use?

2. does an SAS module keep a larger in orbit without someone manually controlling it?

Thanks

edit: side note, is there a way to identify the components that a ship is build with while its flying in space? such as a key to hold down while clicking on it.

[rryy]

To answer the first question, there is no need for station-keeping in KSP because your station is put on rails when you are not controlling it or nearby it.

[Ogre]

1. You don't need an engine to maintain orbit as long as you're out of the atmosphere. 70k is the line for that on Kerbin, so the lowest orbit you want for a station is probably about 75k.

2. Not sure what you're asking. An ASAS module, if switched on, will keep a vessel pointed in the same direction, even when you're controlling a different ship. SAS modules just provide more torque for turning. ASAS will use SAS to maintain a heading, but all the command pods also provide some amount of torque, so SAS modules are often not needed. Neither does anything to keep you in orbit.

You can right click on parts to get a popup with info about them, and buttons to control them for things like engines, gear, fuel tanks. I think structural only parts may not have popups, but most of the important stuff does.

[HoY]

Someday people will stop sharing misinformation about SAS, unfortunately today isn't that day. SAS does not provide any steering torque whatsoever, it only adds dampening torque to stop your ship or station from spinning or rotating when you activate it. Command Pod Torque is the only type of torque (including probe core but it uses the same type of torque) that will help you turn your ships or stations.

You might want to consider having a reaction control system installed on the station to make and small changes in rotation you wish to make a little quicker, but no you don't need and actual engines installed on it. (Once you have it launched to its desired altitude and inclination that is)

[Vanamonde]

To add to/clarify what others have posted: 1) Orbits do not decay or mutate in KSP as long as you do not hit atmosphere or encounter the gravity of another body. ALL KSP orbits are permanent. 2) The various kinds of SAS are only concerned with attitude control, keeping the craft pointed in the right direction or rotating it, and exert no other influences. They won't help or hurt a craft freefalling in orbit.

[HoY]

To add to/clarify what others have posted: 1) Orbits do not decay or mutate in KSP as long as you do not hit atmosphere or encounter the gravity of another body. ALL KSP orbits are permanent. 2) The various kinds of SAS are only concerned with attitude control, keeping the craft pointed in the right direction or rotating it, and exert no other influences. They won't help or hurt a craft freefalling in orbit.

You Can use the RCS to alter your orbit quite significantly if your not careful with it

[Uberick]

In regards to "keeping" a station in orbit. . . no, as long as you keep it out of the atmosphere(70k for kerbin), it will stay up on its own. It does NOT need an SAS unit of any type either. the only thing that an SAS will do it stop your vessel from rotating when it's on. An ASAS unit will attempt to maintain current heading when active, as well as fight roll. When you are not in control of the station, it will automatically maintain its heading on its own.

As for engines. . . it depends on what you want to do with the station. I have some stations with engines on them so I can re position them as I want. If all you want your station to do is "sit" in orbit, it doesn't need engines at all. It doesn't even need RCS if you don't plan on rotating it quickly either. If you stick a command pod on it to give it some torque, you can re orient most stations with that alone.

[Brok3n]

Thank you for the replies. I wish the descriptions for components in game were more straight forward and less silly. It would greatly reduce the learning curve for new players.