Set speed: altitude or attitude hold autopilot

[Azimech]

For traversing large distances across a surface in the least amount of time without constantly having to correct the pitch and alttude, how about a Orbiter style altitude hold button. One that uses distance to target, not altitude above ground level, obviously.

Attitude hold is nice if you want to keep the focus on a planet while orbiting it. In Frontier I created a stable orbit, switched engines off, accelerated time and fired my laser until the internal tanks were empty. Then I switched on autopilot so the nose of the craft always pointed towards the center of the planet. Hey, not everyone wants to be busy all of the time ;-)

[Brianetta]

I'd like an autopilot function that will do nothing but keep the ship pointed at, or away from, the velocity vector (that is, let you fall along your trajectory pointed forwards or backwards).

I should add: letting you fire thrusters at will (:

[Azimech]

Ah, the prograde/retrograde function. Is well done in Orbiter too.

[Brianetta]

If you (and Orbiter) want to call it that, sure. To me, those words describe whether you're orbiting with, or against, the rotation of the body, and has absolutely nothing to do with the attitude of the vehicle.

[Azimech]

It's not just me or Orbiter, it's standard spaceflight lingo.

http://en.wikipedia.org/wiki/File:Bi-elliptic_transfer.svg http://math-ed.com/Resources/GIS/Geometry_In_Space/Bsf/4/bsf4-1.html

And NASA uses it too:

http://mars.jpl.nasa.gov/spotlight/porkchop01.html

[Brianetta]

Yes. A retrograde burn is one in the direction of travel. A retrograde orbit is one that's in the opposite direction to the planet's rotation. You need to be much more specific; pointing your ship backwards is not retrograde, even if firing the main engine in that position is a retrograde burn. Your prograde orbit will still be prograde orbit after that burn, but you'll have reduced orbital energy.

Please, don't try to teach me about orbits. I set a challenge back in April: http://www.spacesimcentral.com/forum/viewtopic.php?f=35&t=2026

[Azimech]

Okay, call it whatever you want. I don't care.

[s20dan]

lease, don't try to teach me about orbits. I set a challenge back in April: Hehe, grow up boys ;)

Yeah in orbiter they called any acceleration in the opposite direction to your orbit, a retro-grade path or burn or whatever. Its not a retrograde orbit until like Brian Aldrin said, you are travelling in the opposite direction to rotation. (Usually an inclination >90) But its a nitpick... Fact is pointing (accelerating) in the opposite direction to a prograde orbit is essentially a path towards a retro-grade orbit. Given enough time and delta-v. So to me, a Prograde Burn, or RetroGrade Burn sounds more apt.