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#1 2025-10-28 23:05:18
- Oldfart1939
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- Registered: 2016-11-26
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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 2025-10-29 06:02:22
- tahanson43206
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Re: Starship Lunar Lander and landing legs
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#3 2025-10-29 10:36:28
- GW Johnson
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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 (2025-10-29 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 2025-10-29 11:02:23
- Void
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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 (2025-10-29 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 2025-10-29 15:41:53
- kbd512
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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 2025-10-29 15:44:07
- SpaceNut
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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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#7 Yesterday 14:51:03
- SpaceNut
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Re: Starship Lunar Lander and landing legs
Lunar Starship was never meant to come home to Earth, SpaceX admits
SpaceX’s lunar Starship was never designed to blaze back through Earth’s atmosphere in a shower of plasma. Instead, the company has quietly positioned its Human Landing System as a one‑way ferry that lives and dies in cislunar space, while NASA’s Orion capsule handles the brutal trip home. That architectural choice, long embedded in Artemis planning documents, is only now breaking through to a wider public that assumed every Starship would eventually come back to Earth.
Framed correctly, this is less a retreat from reusability than a bet on specialization. By stripping out the heavy heat shield and recovery hardware, SpaceX can turn its lunar variant into a tall, fuel‑hungry elevator between orbit and the Moon, while the rest of the Artemis stack focuses on launch and reentry. The tradeoffs behind that decision reveal how NASA and SpaceX are trying to thread the needle between ambition, schedule pressure, and basic physics.
Artemis needs a lunar shuttle, not a return capsule
NASA’s Artemis architecture was built around the idea that no single vehicle would do everything, and that includes the trip home. The agency’s own outline for Artemis III makes clear that astronauts will launch on the Space Launch System, ride in Orion to lunar orbit, then transfer into a separate lander for the descent and ascent. The Artemis program description spells out that SLS and Orion are the pieces designed for deep‑space transit and Earth reentry, while the lander is a dedicated vehicle for the last leg between orbit and the Moon’s surface.That division of labor is why NASA refers to SpaceX’s vehicle as the Starship Human Landing System, or HLS, rather than simply Starship. Agency material on the Initial Human Landing concepts shows a tall, stripped‑down lander on the Moon, with Orion waiting in lunar orbit as the ride home. In other words, the mission design assumes from the start that the lunar Starship is a shuttle between the Moon and orbit, not a capsule that ever sees Earth’s atmosphere.
Inside the one‑way Starship design
SpaceX’s own technical descriptions underline that the lunar lander is a specialized branch of the broader Starship family. A detailed overview of Starship‑HLS notes that the Human Landing System is derived from Starship but modified for operation as a lunar lander, and explicitly states that this configuration is not designed to return to Earth. That is not a late‑breaking compromise, it is a core assumption baked into the hardware, from the missing heat shield to the absence of aerodynamic control surfaces needed for atmospheric entry.The logic behind that choice has even filtered into public discussion among enthusiasts and engineers. In one widely shared explanation, Forrest and Townsend tell fellow fans that engineers “dont’ plan on ont he lunar starship to return to earth, no heatshield, save on the cerami,” while David Cluett promises to explain the trade in layman’s terms. The point is simple: every kilogram not spent on ceramic tiles and reentry systems can be spent on propellant, cargo, or life support for the lunar mission itself.
Why Orion still matters in a Starship era
The decision to keep the lunar Starship in space also explains why Orion remains central to NASA’s plans, despite Starship’s headline‑grabbing capabilities. A technical discussion of whether the lander could replace Orion, framed as Can Starship Lunar return to Earth orbit so Orion is not needed anymore, points back to the reality that Orion on SLS is planned to handle the high‑energy return and splashdown. The Orion capsule is built around a robust heat shield and abort systems that the lunar Starship variant simply does not carry.Programmatically, that means Artemis is locked into a choreography where SLS, Orion, and the lander are all indispensable. The SLS missions listed for Artemis I, Artemis II, and beyond show a steady cadence of Orion flights, while separate documentation describes how the Starship Human Landing will be instrumental in ferrying crews from lunar orbit to the surface and back. That is why, even in a Starship era, Orion’s role as the Earth‑return vehicle is not a redundancy but a structural pillar of the mission design.
A “simplified” mission profile, still complex in practice
As schedule pressure mounts, SpaceX has been working with NASA on what it calls a simplified mission architecture for the lunar lander, but that streamlining does not include bringing the vehicle home. Company representatives have described to NASA a Starship for NASA approach that reduces the number of on‑orbit refueling events and mission steps while still delivering astronauts to the lunar surface. A separate account of that simplified approach notes that the company is defending the viability of its lander even as it trims complexity to hit key milestones.Critics inside the space community have questioned whether those changes are enough. At a high‑profile event, former NASA leaders Charlie Bolden and Jim Bridenstine expressed skepticism that the current Starship schedule could deliver on time, even with a leaner mission design. Yet SpaceX has publicly stood behind its timeline, with one detailed feature on its lunar plans, titled around Fly Me to the Moon, stressing that, unlike Apollo, Unlike Apollo, Artemis III will rely on a multi‑vehicle choreography that includes several crucial milestones in 2025.
Refueling, timelines, and the politics of delay
Behind the scenes, the biggest technical swing remains in‑space refueling, which is essential if a non‑returning lander is going to haul enough propellant to and from the Moon. SpaceX’s official updates describe how the next major flight milestones tied specifically to HLS will be a long‑duration flight test and an in‑space propellant transfer in Earth orbit. Without those capabilities, the one‑way lunar Starship would struggle to carry the fuel it needs for multiple sorties between lunar orbit and the surface.That technical risk feeds directly into political anxiety. In one public exchange, Rob Jacobs But the points out that the many Falcon 9 flights are irrelevant to NASA’s immediate problem, because what the agency needs is HLS, which is a special version of Starship. That concern has grown loud enough that NASA has signaled it may consider new proposals from other top space companies to get America back to the Moon if delays mount, a reminder that the lunar Starship’s one‑way design does not insulate it from competition.
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