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Athena landed in a dark crater where the temperature was -280° F / -173° C
251–260 of 277 posts
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#252Earlier quoted context omitted.
But would they need to be in the orbit? Since nothing is on the moon, couldn't you just create a GPS array on the ground?
>nothing is on the moon It's not exactly nothing, the moon itself with its mountains is there and blocking the radio signal and it means propagation isn't unlike that of VHF/UHF on Earth. You still only have no visibility beyond the horizon. In order for it to be visible and useful during landing you would need the base station to be reasonably close. I guess that would make it more akin to ILS/VOR/DME than GPS. That…
the moon is made of cheese everyone knows this
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#253Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#254Earlier 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.
The first moon landing cost $300 billion+ in today's dollars.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#255Earlier quoted context omitted.
But would they need to be in the orbit? Since nothing is on the moon, couldn't you just create a GPS array on the ground?
For a GNSS-type system to work, you need four transmitters in sight. This would imply a moderately dense ground network on the moon for a receiver at orbital height -- and as this article points out, we're not doing great at building even a spare ground network of right-side-up transmitters right now -- but would need increasing density for a descending receiver. We don't really have challenges right now with accurat…
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?
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#256Welp, I worked on this one. Specifically, I worked on the laser rangefinders which are under so much scrutiny. I no longer work at Intuitive Machines, but I'm certainly interested in finding out what happened to the lasers this time.
Ooo. Not sure if you can tell us anything. If you can’t I totally understand. But in case you can: Was a radar based altimeter considered? How do you guys deal with kicked up regolith? (I have seen first hand how hard heavy snow is on lidars, and would imagine that regolith “shower” is similar, but what do I know.)
The lasers are smaller and lighter than most radar systems. They're also pointed out at about 45 degrees from the lander and they're not supposed to be used for the last few dozen meters of descent.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#257Welp, I worked on this one. Specifically, I worked on the laser rangefinders which are under so much scrutiny. I no longer work at Intuitive Machines, but I'm certainly interested in finding out what happened to the lasers this time.
some of the comments here are suggesting the lander chose that spot, as opposed to crashing and skidding across the surface before settling in the spot purely due to inertia, what's the merit to that?
I did not work on the HDA algorithm which is responsible for landing site deviation, but this technology was inherited from NASA's Project Morpheus, which could intelligently detect hazards and divert to safer sites.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#258Earlier quoted context omitted.
Is that really "space" as opposed to "the lingering effects of the big bang"? (or less interestingly, the temperature of the CMB photon gas)
I don't think a photon can exist outside of space, but I'd be very interested to hear of any alternate points of view on that!
What I mean is that isn't the temperature of "space" -- if we're being pedantic. Such a temperature would presumably be measured by the blackbody radiation of... space, if space were a blackbody.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#259Earlier quoted context omitted.
The space surrounding you may not have a temperature but your spacecraft does, and it will lose heat via radiation, batteries and electronics will stop working after your temperature reaches a certain low.
>The space surrounding you may not have a temperature Just to be pedantic, it actually does, which is the microwave background radiation. But that doesn't detract anything from your point.
There's also ~80,000 molecules per cubic centimeter on the moon. It's extremely thin but there's still stuff out there it's just a VERY slow transfer because there are so few collisions compared to what you'd get on Earth.
Re: Athena landed in a dark crater where the temperature was -280° F / -173° C
#260Earlier quoted context omitted.
For a GNSS-type system to work, you need four transmitters in sight. This would imply a moderately dense ground network on the moon for a receiver at orbital height -- and as this article points out, we're not doing great at building even a spare ground network of right-side-up transmitters right now -- but would need increasing density for a descending receiver. We don't really have challenges right now with accurat…
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.