@uhoh You caused me to dust off my old trajectory optimisation library by that cycler inquiry, and now all the fun projects from back then are all coming back to me.
Like a manned Mars mission profile that uses a Venus flyby to cut down the waiting time otherwise needed at Mars to wait for the Hohmann transfer to line up.
That includes "fun" things like deciphering my old unlabelled diagrams to figure out what my flyby strategy actually was:
If I'm reading things correctly, it's a 750 day roundtrip Earth-Venus-Mars-Venus-Earth, with a 90 day stay on Mars.
Main drawback is the two required 2890 m/s impulses to get into/leave low Mars orbit.
One of them can of course be replaced with aerobraking, but I figure it's better to leave the habitat in an eccentric capture orbit instead, and only transfer the crew with a small craft down to/up from low Mars orbit, where the lander is waiting.
At least it's shorter than the usual 900 days, at negligible extra delta-v cost.
I know faster profiles are possible, involving only one Venus flyby, but those have some ugly delta-v requirements:
^ That fast Mars-Venus transfer at the end is a real drainer, and the re-entry speeds at Earth are very high.
@SE-stopfiringthegoodguys I was sure there was a lot more to what you were saying than what was there initially! Thanks for doing into "dust off" mode :-)
I don't have any time to do think until the weekend, but what confuses me is that I think of a "cycler" as something that keeps working over time. It looks like something that will work a few times only.
Maybe the flybys are constantly advancing the line of apses to keep it slowly moving around?
@SE-stopfiringthegoodguys no I don't know much at all about real-world orbits. I just play with math an Python.
If it's the later (edi: it was the later), it does indeed work by advancing the line of apses by about 20 degrees for every four synodic Venus-Mars periods
How about I ask a separate question "What makes a cycler a cycler?"
That way one can explain the key points without being encumbered with specifics. Examples are at the answerer's discretion.
I don't doubt that for someone who's immersed in the subject those would be all that's needed. But the rest of us mortals may not have sufficient insight to see that.
Ya, and in fact it's perfectly okay (as you know) to ask an answer your own question, and that might be better in this case because you have a better sense of what needs to be asked.
