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Athena landed in a dark crater where the temperature was -280° F / -173° C

arstechnica.com

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Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#61

Post by JumpCrisscross »

sandworm101 wrote: post #56
JshWright wrote: post #40

Earlier quoted context omitted.

The top-heavy design didn't help things either. I'll be shocked if they don't go three-for-three on landing sideways given IM3 has the same tall design.

>> The top-heavy design didn't help things either Just wait for SpaceX to start trying to land starships on the moon. Also vertically. Also doomed to tip over whenever the surface is slightly out of spec. https://www.spacex.com/humanspaceflight/moon/

> Just wait for SpaceX to start trying to land starships on the moon. Also vertically

SpaceX has done it. To date, other nation-states have tried and failed to replicate their achievements in this domain.

IM’s design is wrongly optimised and probably requires a rethink. That the CEO won’t contemplate this isn’t a great sign for the company.

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#62

Post by dietr1ch »

layer8 wrote: post #37
muzani wrote: post #21

Earlier quoted context omitted.

This actually puts it into perspective, knowing it's closer to absolute zero than room temperature.

It’s roughly a third of room temperature.

Which is hard to grok since a third of something warm doesn't seem to be extremely cold.

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#63

Post by tempodox »

layer8 wrote: post #37
muzani wrote: post #21

Earlier quoted context omitted.

This actually puts it into perspective, knowing it's closer to absolute zero than room temperature.

It’s roughly a third of room temperature.

Exactly, the Kelvin unit makes it easy to see that. I can't believe they used fucking Fahrenheit in the title.

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#64

Post by timmg »

tekla wrote: post #59
JshWright wrote: post #40

Earlier quoted context omitted.

The top-heavy design didn't help things either. I'll be shocked if they don't go three-for-three on landing sideways given IM3 has the same tall design.

Why do people keep thinking this thing is top heavy just because its taller than wide? The heavy bits are at the bottom.

> Why do people keep thinking this thing is top heavy just because its taller than wide?

Because it keeps falling over?

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#65

Post by CamperBob2 »

JumpCrisscross wrote: post #61
sandworm101 wrote: post #56

Earlier quoted context omitted.

>> The top-heavy design didn't help things either Just wait for SpaceX to start trying to land starships on the moon. Also vertically. Also doomed to tip over whenever the surface is slightly out of spec. https://www.spacex.com/humanspaceflight/moon/

> Just wait for SpaceX to start trying to land starships on the moon. Also vertically SpaceX has done it. To date, other nation-states have tried and failed to replicate their achievements in this domain. IM’s design is wrongly optimised and probably requires a rethink. That the CEO won’t contemplate this isn’t a great sign for the company.

SpaceX has done it.

SpaceX has landed Starship on the moon?!

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#66

Post by littlestymaar »

Can someone ELI5 why it's at that temperature?

I mean, because it's in the dark I'd expect it to reach equilibrium with space background thermal radiation which is around 3K. Yet its 100K. Where does that heat comes from? It radiates from earth? Conduct through the floor coming from the inner of the moon itself? (Is there some kind of geothermal gradient on the moon BTW?)

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#67

Post by JumpCrisscross »

CamperBob2 wrote: post #65
JumpCrisscross wrote: post #61

Earlier quoted context omitted.

> Just wait for SpaceX to start trying to land starships on the moon. Also vertically SpaceX has done it. To date, other nation-states have tried and failed to replicate their achievements in this domain. IM’s design is wrongly optimised and probably requires a rethink. That the CEO won’t contemplate this isn’t a great sign for the company.

SpaceX has done it. SpaceX has landed Starship on the moon?!

SpaceX has repeatedly and reliably landed vertical stacks. On any body. Out of the engineering problems inherent to HLS, sticking the landing isn’t material because for them, for that team, it isn't as novel a problem as e.g. in-orbit refuelling or getting Raptors to relight on the Moon.

Put another way, just because SpaceX has done it doesn't mean the same problem carries the same risk for a team like IM's.

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#68

Post by tekla »

timmg wrote: post #64
tekla wrote: post #59

Earlier quoted context omitted.

Why do people keep thinking this thing is top heavy just because its taller than wide? The heavy bits are at the bottom.

> Why do people keep thinking this thing is top heavy just because its taller than wide? Because it keeps falling over?

The landing leg broke. How does that show you its top heavy?

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#69

Post by dmurray »

areoform wrote: post #9

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. Robert Tru…

> China adopted the Surveyor / Apollo-era philosophy. Their first successful lander, Chang'e 3, used the same hover & fall technique as Surveyor.

Dropping the last 4 metres isn't a sign of having a ruggedized, over-speced "takes a lickin' and keeps on kicking' approach". In lunar gravity, you could drop a raw egg from that height and not perturb the chick inside.

Instead the aim is to avoid throwing up too much moon dust with retro rockets.

Luna 9 (1966) really did need to withstand a bit of a bump, but it was 22km/h, comparable with a fast running pace or a car in first gear, not a high speed impact.

Re: Athena landed in a dark crater where the temperature was -280° F / -173° C

#70

Post by FredPret »

areoform wrote: post #16
jjmarr wrote: post #14

Earlier 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…

> stuff that matters

Matters to whom?

Answer: that's the definition of a customer in an engineering project

Matters how / why?

Answer: those are the requirements / user stories.

Helping people by doing engineering feels good and is the right thing to do, but formalizing this process a bit does not detract from it.

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