Kerbals using jetpack on kerbin rise up a bit then stay there until stepping off the invisible perch

[schlosrat]

If a Kerbal on Kerbin activates their jetpack and attempts to fly (press space to go up), the Kerbal will rise up a few cm slowly, then stop. When you release the space bar and the jetpack stops firing. they stay put as if on an invisible perch. If you move forward, back, or to either side (WASD) then there's an audible and visual stepping down. The game appears to know they're not at surface level so gives you the sound effect as if the Kerbal stepped off a curb and on the pavement or whatever.