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#1 2025-10-28 23:05:18
- Oldfart1939
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- Registered: 2016-11-26
- Posts: 2,488
Starship Lunar Lander and landing legs
We've had some conversation on this forum about landing methods for the lunar lander.
Here's a fairly interesting YouTube discussion about landings and how to carry it out.
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#2 Yesterday 06:02:22
- tahanson43206
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- Registered: 2018-04-27
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Re: Starship Lunar Lander and landing legs
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#3 Yesterday 10:36:28
- GW Johnson
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- From: McGregor, Texas USA
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Re: Starship Lunar Lander and landing legs
I saw the videos, plural. The first one takes on their rough field landing system. The second takes on refueling in space, and cut off before it was finished.
It appears that if you decide to land tall things, you need a discerning pilot to target the right spot amongst all the hazards, and who can adapt the positioning of landing surfaces to the unevenness just before the touchdown. That has to happen faster than humans can act. This is going to be based on AI, apparently.
Tip-over after touchdown on rough surfaces with tall, narrow objects is a real thing, and some recent commercial landers have demonstrated that ugly little fact of life. Any horizontal speed at touchdown can tump you right over in a split second, even in low lunar gravity. That was the proximate cause of the Japanese failure, and at least one of the two US failures. Both designs were tall and narrow, presuming the controls were good enough to adapt.
Given the track record of failures and crashes because of events unanticipated by the programmers with Tesla self-driving software, I would hesitate to take the same approach with a crewed device as the Japanese and that one American commercial lander company. The other American commercial lander was more squat and more successful.
Controls can only be so good, not perfect. And the moon is infamous for having unevenness and randomly scattered but dense distributions of obstacles and hazards.
But my fears may or may not be justified. I just do not trust AI, because I see lots of errors and falsehoods out of the ones available to the public. I still think the term AI is an oxymoron: there is NO intelligence or understanding of anything there, there is only imitation of style plus very high speed. Computers process bad data as well as good data. It all looks the same when it comes out of them.
GW
Last edited by GW Johnson (Yesterday 10:39:30)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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#4 Yesterday 11:02:23
- Void
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- Registered: 2011-12-29
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Re: Starship Lunar Lander and landing legs
I try not to interfere with professional conversations, but I see some things.
For rough landings, the special landing engines may be able to counteract a toppling tendency. They are not too powerful though.
I keep seeing reports that the Lunar lander engines will be retractable. I cannot understand why they would do that.
I also suggest that some cargo could be attached directly to the landing legs to make the ship less top heavy, and to make cargo accessible without the elevator.
It is my opinion also that landing legs could be left behind on the Lunar surface like the lower stage of the LEM was left behind. This would reduce propellant consumption.
Legs, in my opinion should be made of materials desired on the Moon that cannot be gotten easily from the Moon. They also should be constructed to accommodate cargo containers.
Just my "Two-Nickles". (Inflation).
Ending Pending 
Last edited by Void (Yesterday 11:07:17)
Is it possible that the root of political science claims is to produce white collar jobs for people who paid for an education and do not want a real job?
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#5 Yesterday 15:41:53
- kbd512
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- Registered: 2015-01-02
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Re: Starship Lunar Lander and landing legs
ULA's "crasher stage" horizontal lander used thrusters mounted to both ends of the tank to land a Centaur-sized propellant tank with far less probability of "tipping over" during the landing. Creating a sufficiently wide landing gear track for a tallboy beer can is much easier to do when the can is laying on its side. Trying to land the propellant can on-end requires very large and heavy landing gear to create a track wide enough to avoid tipping over. Since the moon is 1/6th Earth gravity and some of the propellant will be consumed during descent, far less propulsive power is required from the thrusters, which makes mounting them on either end of the stage less problematic.
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#6 Yesterday 15:44:07
- SpaceNut
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- From: New Hampshire
- Registered: 2004-07-22
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Re: Starship Lunar Lander and landing legs
here is one of many topics.
Much changes when a lunar version does not need to come back to earth.
Six-legged freaks - can the Starship land on those legs?
The legs were also part of our discusions on Landing legs for the BFR
some feel that a starship for the moon is over kill SpaceX should withdraw Starship as an Artemis lunar lander.
Of course the Mars version is also a puzzle with the full sized starship for colonizing feeling that support for the ship requires Starship concrete Mars landing pad
Of course right sizing the ship is another alternative. Forty 40 Ton Mars Delivery Mechanism
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