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

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

#261

Post by pclmulqdq »

ricardobeat wrote: post #254
pclmulqdq wrote: post #239

Earlier quoted context omitted.

$1M was the amount they spent on the lander. If I recall correctly, they got a ride to the moon for free. Delivering that amount of mass to the moon is worth O($10M). It seems incentives were not properly aligned for this group. I should also point out that you can fly a scientific mission on a 1U cubesat for ~$100k all in (including launch cost), which puts it in a very different regime.

The first moon landing cost $300 billion+ in today's dollars.

Yeah, this is not that, though. We know how to get to the moon, and a small probe is lighter than 3 people plus a vehicle that allows them to make a return trip.

This launch, which had a few other payloads, too, reportedly cost NASA $62 million.

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

#262

Post by scoofy »

tliltocatl wrote: post #260
scoofy wrote: post #255

Earlier quoted context omitted.

If you were trying to land on a specific site though, couldn't you drop down a dozen or so transmitters at the potential landing site? The assign them a location, and have them transmit the relative location to anything landing near them?

How would you drop them? Don't think a radio transmitter would survive a hard landing, so you will need a proper lander (with altimeter) for each transmitter. And at that point you can just strap your actual payload instead of the transmitter.

The point would be you could drop them a bit randomly, once they land, find out where they are, and tell them where they are, to then talk back to the payload as it's landing.

It's the moon, even a hard landing isn't that hard.

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

#263

Post by verzali »

dredmorbius wrote: post #246
verzali wrote: post #189

Earlier quoted context omitted.

It depends on the size of the satellite and its power use. Small spacecraft often don't use enough power to generate enough heat to warm themselves. The problem then is batteries get cold (which is one of the places you need heaters) and become inefficient and then you end up in death spiral. Here the probe likely wasn't generating enough power anyway, so that would almost certainly kill it before the cold.

The problem is less the quantity of heat generated than of shedding that heat . Even modest electronics emit several watts of thermal waste heat, and given that the entire satellite is in a highly-insulating vacuum, as well as subject to solar insolation (at 1 kW/m²), it's easy to exceed thermal budgets.

You can do the sums. Spacecraft lose heat by radiation and if you do the sums for a small spacecraft you can see the equilibrium temperature is low enough that you don't need to take any special measures to shed the heat.

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

#264

Post by literalAardvark »

nomel wrote: post #250
literalAardvark wrote: post #231

Earlier quoted context omitted.

> 3d positional/velocity precision. SpaceX has prove that they can reliably land on a target, usually within meters On Earth, which has GPS. On a very highly engineered landing surface. Landing on inertial guidance on soft regolith is a whole different ballgame.

> Landing on inertial guidance Which is not the future. Optical/lidar/positioning radio is the future, to make it closed loop (NASA’s Laser Retroreflector Array for high, lidar/optical for low altitudes). > On a very highly engineered landing surface. As I mentioned, we shouldn't assume the earthy landing legs are used. That would be a very silly assumption. From what I can extract from your comment, you believe that…

It may be possible. It may also be that the regolith is too fluffy in that area to support such a large structure without a pad. I don't believe we know.

Athena had multiple laser altimeters on board: they failed to get a fix, perhaps because of the weird surface.

It's my opinion that this isn't something that's easy to do, even for a company that has landed on Earth.

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

#265

Post by h3half »

Aerroon wrote: post #220

Is there any reason why we couldn't have some rudimentary GPS-like satellites around the moon? That could help out these kinds of landers, no?

Not really, yes (though possibly not for the actual landing, depending on accuracy), and it's actively being worked on: https://www.intuitivemachines.com/post/nasa-awards-intuitive...

IM didn't win the contact because of their landers per se, but obviously as a company they have a vested interest in this kind of lunar infrastructure. Being able to build it with a bunch of public money is a huge win for them

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

#266

Post by Yeul »

rout39574 wrote: post #93
tremon wrote: post #47

Earlier quoted context omitted.

I don't understand what you are objecting to. Is it just the phrasing that's bothering you? Because from my point of view, "houses that don't collapse" and "machines that can travel vast distances" are all formulations of customer needs. And dealing with contraints is pretty much engineering 101, every project is at the very least constrained on two of these axes: cost, construction time or material availability.

Not GP, but I think the objection is: the engineer wants to build a thing cheaply enough that it functions, and then cheaply as can be while maintaining function. The MBA wants to build a thing as cheaply as can be while extracting maximum value from the process. Maintaining function is only relevant inasmuch as is necessary for marketing. Enshittification is offensive to the engineer, and is a deliberate calculated…

Wait what is even the economic case of landing on the moon? The reason why anyone even does it is either for science or propaganda.

Musk's ranting about colonising space is cute but spaceX is building shit for NASA and the Pentagon.

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

#267

Post by Yeul »

driggs wrote: post #137
kQq9oHeAz6wLLS wrote: post #132

Earlier quoted context omitted.

Well, there's a natural barrier to entry, i.e. it costs millions on dollars and years of time to be able to "crash" your "junk" onto the surface. So it's not like a bunch of hobby rocketeers are throwing away their McDonald's garbage. By the way, in comparison to the cost and complexity of said "junk", everything you own is cluttering up the Earth. You should really do something about that.

Are you making the argument that anyone with enough money should be able to do whatever they want on the moon? Giant neon McDonalds billboards visible from everywhere on Earth? Mining with zero restriction on impacts to the surface of the Moon or its atmosphere? Apparently the HN crowd doesn't stand anyone criticizing a "startup", but I'm asking a legitimate question. So far most of the junk we've launched onto the M…

America wipes it's ass with international regulation.

Besides if countries start shooting eachother in space they'll start doing it on earth.

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

#268

Post by dingaling »

tekla wrote: post #68
timmg wrote: post #64

Earlier quoted context omitted.

> 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?

Because itbit wasn't top-heavy, a broken landing leg would just leave it slumped at an angle. Not fallen-over.

Consider the difference between removing the leg of a chair versus a stool.

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

#269

Post by adastra22 »

pclmulqdq wrote: post #239
adastra22 wrote: post #238

Earlier quoted context omitted.

This is best compared to being a lunar landing cubesat. IM is an order of magnitude cheaper than a comparable NASA lander. Cheap is the point, and cheap carries with it some concessions to risk.

$1M was the amount they spent on the lander. If I recall correctly, they got a ride to the moon for free. Delivering that amount of mass to the moon is worth O($10M). It seems incentives were not properly aligned for this group. I should also point out that you can fly a scientific mission on a 1U cubesat for ~$100k all in (including launch cost), which puts it in a very different regime.

Getting to the moon is vastly more expensive. 40x is the multiplier that is typically used in the industry. Prior to cancellation, NASA spent $433M on the VIPER lander + rover--NOT inclusive of launch costs.

$1m is crazy cheap.

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

#270

Post by pclmulqdq »

adastra22 wrote: post #269
pclmulqdq wrote: post #239

Earlier quoted context omitted.

$1M was the amount they spent on the lander. If I recall correctly, they got a ride to the moon for free. Delivering that amount of mass to the moon is worth O($10M). It seems incentives were not properly aligned for this group. I should also point out that you can fly a scientific mission on a 1U cubesat for ~$100k all in (including launch cost), which puts it in a very different regime.

Getting to the moon is vastly more expensive. 40x is the multiplier that is typically used in the industry. Prior to cancellation, NASA spent $433M on the VIPER lander + rover--NOT inclusive of launch costs. $1m is crazy cheap.

$1M is not the full price of this mission. $1M is the price of the lander only. They were given a ride on a rocket whose total bill was $62.5 million (just for the launch, but spread among 4 missions).

When you spend $1 million but get $10 million of stuff for free, it's not really a "$1 million project."

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