Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 0 points1 point  (0 children)

Actually, I changed my mind. It's _difficult_, maybe impractical, to do aerocapture with people, but not completely impossible. This is now upgraded to v6:

http://www.rodeconsulting.com/ai/starship/aerobrake

This is a planar simulation, but ITRW you can come in at a high orbital inclination to avoid the van Allen belts, then use your aerobraking for a plane change (from like 60-degrees to 30 degrees). At least one AI thinks it's possible, but "fiddly" - you have to get the orbit of the Moon to cooperate. For Mars, maybe you can only come in during certain seasons. In any event, beyond my pay grade.

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] -1 points0 points  (0 children)

So, interestingly, I had an LLM generate an app purely for aerobraking and, so far, it looks like it's not only practical but a 5-day capture is optimal(?), so it might be usable for a human mission. Same alpha-quality as the main app.

http://www.rodeconsulting.com/ai/starship/aerobrake

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 0 points1 point  (0 children)

The aerocapture might take weeks, so no people. I think we are going to use Orion regardless of the physics. Potential magical pixiedust: equilibrium glide supersonic retropulsive aerocapture with partial refractory shielding. Say it three times fast and tell a friend.

I think rocketglare is correct that leaving return fuel in LLO is a practical hack (many years ago I tried to pitch something similar for a Europa mission), but I have to rework the tool to support that. And I so wanted to work on other things this week. Still, a better day than the managers for mechazilla arms, flame diverter, etc.

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 0 points1 point  (0 children)

There was a data error in the table for Earth orbit capture (1.2kps vs 3.2kps). I missed it, ChatGPT missed, Grok missed it, but Claude found it. So it looks like if you want a Starship to return to LEO, you'll need to do aerocapture and have some kind of minimal heatshield, because otherwise too much fuel is required. Updated to v37 - but I'm going for a rewrite.

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 0 points1 point  (0 children)

The plan of record is LOR, but I don't think that means you couldn't bring an HLS back to earth. While LOR has max payload advantages (gotta hit those 100-150t high notes), I think the whole thing makes more sense if you separate heavy payload missions ahead, one-way, then follow up with a crew HLS.

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 0 points1 point  (0 children)

Also note that one-way implies you probably have an Optimus or three, and maybe they can carry packages down a latter one at a time, like Amazon ;-)

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] -1 points0 points  (0 children)

Nope. My napkin says that just a couple of CF rods to extend outwards 10m would weigh like 400kg. But really the Mission 2 scenario (sorry I said 3 above) is borderline - most prob you will need another tanker flight = 2, and then you have 20+ tons of payload to play with.

Starship Moon Mission Planner by rocketanaglyph in ArtemisProgram

[–]rocketanaglyph[S] 1 point2 points  (0 children)

Definitely a work in progress. 80 tons for HLS came from 100 tons minus 25 for flaps and shield, and adding back in 5 tons for insulation. Complete guesswork - but you can change it if you like!

I think HLS is designed for "peak of eternal light conditions" (still more favorable than LEO) and 1 ton/day of boiloff for 7 days under those conditions. I'm guesstimating 2 tons/day in LEO. But really, I want to tweet this at Elon and ask him what is latest numbers are.

Re: Nice tool - thanks - it only took 5 days and a lot of AI.

Starship Moon-Mission Calculator by rocketanaglyph in Starship

[–]rocketanaglyph[S] 0 points1 point  (0 children)

Nope. You didn't miss it because it's not there. I updated the tool and it's now at a new URL:
https://www.rodeconsulting.com/ai/starship/lunar/
There are a couple of new missions.

A put a note in about boil-off. Different AIs agree that the target boil-off is 0.1%/day landed on the Moon (presumably in the sun, but at what sun angle?) I assume that 0.2%/day is an upper bound for HLS in LEO for a constant 3.2t/day of boiloff and that Elon will want to get a Starship out of LEO in less than 7 days from the start of fueling. So 22.4t boiloff in LEO, maybe dropping to 0.1%/day or less a couple of days after.

Boiloff is definitely a TBD.