Not sure...

[Lolkillalevi]

My m/s sign isn't moving does that mean i have a Stale orbit? It moved once and reaaaaaaaaaaaalllyyyy slowly i thrusted a few more meters i'm on escape trajectory for my space station, am i gonna start falling back to kerbin with my throttle off? or am i good i can have the throttle off and i'll stay there?

[Sirrobert]

Look at your periaps and apoaps. If both are above the atmosphere, you are in a stable orbit

[giltirn]

You're in a stable orbit if the ellipse of your orbit doesn't intersect with the planet that you are orbiting (or its atmosphere) - look at the map view. If the velocity is stable it just means you have a circular orbit, which is not necessary to avoid falling back to kerbin.

[Kegereneku]

Am I the only one wondering how he could have a space station in orbit and not know what is a stable orbit ?

[sardaukar11]

acording to his signature, hi has already hitted duna with an impactor, so...

yes, its really strange

[Vanamonde]

Guys, it doesn't matter *why* he wants to know. Not everything is obvious to everybody.

Lolkillalevi: If your speed meter isn't changing, it means you are orbiting levelly at the moment, but that doesn't mean the whole orbit is completely circular. On an elliptical path your speed will be pretty stable around both apoapsis and periapsis, but changing rapidly at the midpoints between them.

Edited November 1, 2013 by Vanamonde