Earlier quoted context omitted.
-173°C.
100K
This actually puts it into perspective, knowing it's closer to absolute zero than room temperature.
Athena landed in a dark crater where the temperature was -280° F / -173° C
21–30 of 277 posts
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#22Kinda explain why Neil Armstrong burned up all their fuel except for a few seconds scoping out the landing site in paranoia. Instead of building all these expensive to launch big landers, why not get some pizza-box sized probes into earth orbit AND THEN do like a slo-mo golf shot arcing to where the moon will be for a super slow/soft landing? Some will fail but if you launch 100 and get 20-30 working, there you go. A…
Space applications of all sorts are screaming out for mass production approaches. With so much design work and verification the actual manufacturing cost tends to be trivial by comparison, the work readily adapted to concurrent manufacturing processes.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#23Earlier quoted context omitted.
> Perhaps it is to save on mass and power so that more payload reaches the surface. It doesn't matter how much mass was saved and how much more payload that allowed to reach the surface if the landing isn't successful. Successful landing is mandatory for anything else to matter. The obviousness of this baffles me that it is taken so haphazardly.
I believe that the thing you are missing is Intuitive Machines aims at landing a lot of spacecrafts, not just one. They hope to have a limited number of failures to land which will teach them how to do it reliably. We might doubt will this work or not, but if we accept the plan then it becomes a rational decision to increase the engineering complexity and risks of failure by saving on mass, because in the long run le…
Again, if you can't stick the landing, you might as well not have any payload on it. So if you're worried about cost, keep testing until you can stick the landing with dummy mass. Once that works, send the real payload. Otherwise, you're just wasting payload.
The mindset difference seems to be that if there's no human on board, so no problemo wasting a lander if something goes wrong. That's just a bad attitude (as well as yaw and roll). If you designed everything with "baby on board" hanging in the window, you'd probably not cut so many corners so sharply. Otherwise, why not just light your cigars with hundred dollar bills. How would you feel if you were on the team building the payload, but the lander guys keep fucking up so you just wasted however much time you spent because "meh, we're just testing". In sports, there's a saying "practice like you play because you play like you practice".
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#24Earlier quoted context omitted.
You're criticizing the prioritization of cost, not the concept of trying to solve for constraints. Engineering is about constrained optimization to meet customer needs.[1] Learning this is a core part of the curriculum at my accredited engineering school. > Engineering design is a process of making informed decisions to creatively devise products, systems, components, or processes to meet specified goals based on eng…
This comment isn't directed at you jjmarr, I appreciate your take, but I think it's important to point out that, > constrained optimization to meet customer needs is MBA-capture in action. For most of its existence as a formal field, engineering wasn't about making geegaws that "meet customer needs." It was about building stuff that matters. Houses that didn't collapse. Roads and machines that made it possible to tra…
The constrained optimization part is good, though.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#25Still unclear what happened. Did they not anticipate a big moon hole or did navigation fail when the rangefinder failed?
I'm not sure what you find unclear. Navigation was fine - "Athena knew where it was relative to the surface of the Moon" - but without a working altimeter it was kinda fucked for actually touching down. Hard landing, skid, tip.
If navigation was fine, why was touchdown on a plateau?
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#26Kinda explain why Neil Armstrong burned up all their fuel except for a few seconds scoping out the landing site in paranoia. Instead of building all these expensive to launch big landers, why not get some pizza-box sized probes into earth orbit AND THEN do like a slo-mo golf shot arcing to where the moon will be for a super slow/soft landing? Some will fail but if you launch 100 and get 20-30 working, there you go. A…
It's definitely possible to target a certain surface location on the moon from low Earth orbit and set off on a trajectory to get there with a single burn. However, as the craft(s) approach the moon and enter its sphere of influence, gravity will kick in and increase their relative velocity to the surface. Another burn (suicide burn if you're feeling lucky) would be needed for the soft touchdown.
The moon is also gravitationally very "lumpy", so some small corrections might be needed along the way as well.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#27Still unclear what happened. Did they not anticipate a big moon hole or did navigation fail when the rangefinder failed?
I'm not sure what you find unclear. Navigation was fine - "Athena knew where it was relative to the surface of the Moon" - but without a working altimeter it was kinda fucked for actually touching down. Hard landing, skid, tip.
Was there no functioning laser or radar altimeter for the final descent phase?
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#28If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering. Robert Tru…
> If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering.
I wonder how much of that is because of public attitudes to government spend. Like if a SpaceX rocket blows up, they're taking innovative, risk-taking approaches to rocket development. If a NASA rocket blows up they're wasting tax payer funding.
Similarly the pressure on NASA to have fewer programs for cost saving is similar. If NASA has two rocket programs, one of which is at a "good enough" level for launching satellites economically into space and one of them is a "safety conscious" rocket for manned launches at a higher per-mission cost, then people look at this and think why is NASA duplicating work and spending. So now they get only one program, so then even launching a GPS satellite is the expensive, human-safe rocket.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#29If you take the time to study the documentation from the 1950s & 1960s, the engineering culture of that era appears to be markedly different from the engineering culture prevalent today. And I think it's deeply rooted in the symbiotic relationship between computing, Baumol's cost disease and our obsession with precision, results-oriented, MBA-style-min-maxing, "good enough for government work" engineering. Robert Tru…
> Perhaps it is to save on mass and power so that more payload reaches the surface. It doesn't matter how much mass was saved and how much more payload that allowed to reach the surface if the landing isn't successful. Successful landing is mandatory for anything else to matter. The obviousness of this baffles me that it is taken so haphazardly.
To a point. Landing a solid brick of aluminum isn't much good, unless the entire goal of the exercise is to get a successful landing of something.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#30Dumb question, but why can't it have a few simple telescopic sticks which extend to flip it over if it lands upside down. Seems it's the second time they fail in this mode.
Mass. Each kilogram costs what, millions? Hundreds of millions?
There's a small chance that navigation or landing fails in a way that would make those legs useful, and an even smaller chance that they'll save the mission.
Given tight budgets, this is almost certainly not a gamble worth taking