Noiredd / PEGAS

Powered Explicit Guidance Ascent System - a KSP & RO autopilot using the Space Shuttle guidance algorithm, UPFG
http://forum.kerbalspaceprogram.com/index.php?/topic/142213-pegas-powered-explicit-guidance-ascent-system-devlog
MIT License
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Use PEGAS in orbital maneuvers #34

Closed AleXmShef closed 3 years ago

AleXmShef commented 4 years ago

Hello. Is it possible to use this algorithm for executing on-orbit non-impulsive burns (i.e. to change orbital parameters of the relatively low-thrust spacecraft which is already in orbit)? And if the answer is yes - any suggestions on how to implement this using existing code?

Noiredd commented 3 years ago

The short answer is no.
The long answer is: I have been thinking about this and I've even made a few experiments in Matlab (see my other repository) to see if it's possible, but I just couldn't get it to work. Even for relatively simple maneuvers of magnitude around 100 m/s delta-v, UPFG just wouldn't converge (or converged to some ludicrous, impossible trajectory). I'd have to look deeper into the maths to figure out why it doesn't work - as of now I'm not sure whether I've been doing something wrong (e.g. with timing of such a maneuver), or maybe there's some fundamental limitation that prohibits this.
Sadly, I'm very low on time these days and don't have enough time to properly maintain this repository (as you can see - sorry for such a late reply, btw), let alone work on major additions like that.

I've been always thinking about a separate, UPFG-based script for executing arbitrary maneuvers, e.g. for fully automated interplanetary missions - I even have a name for it already, just can't get the thing to work :rofl: If I ever succeed, however, this will almost certainly be an entirely separate tool.