[HN Gopher] ESA's Moonlight programme: Pioneering the path for l...
       ___________________________________________________________________
        
       ESA's Moonlight programme: Pioneering the path for lunar
       exploration (2024)
        
       Author : nullhole
       Score  : 77 points
       Date   : 2025-07-14 14:01 UTC (3 days ago)
        
 (HTM) web link (www.esa.int)
 (TXT) w3m dump (www.esa.int)
        
       | CharlesXY wrote:
       | Honestly, pleasantly surprised that this is a European-led
       | initiative, it's really great to see ESA stepping up with such an
       | ambitious project.
        
         | sandworm101 wrote:
         | _Mostly_ European. The ESA map has a little cutout for the one
         | non-european  "cooperator" state on the council.
         | 
         | https://www.esa.int/About_Us/Corporate_news/Member_States_Co...
        
           | ChocolateGod wrote:
           | Canada is currently pretending to be a European country sssh
        
             | saubeidl wrote:
             | We'll annex them before the Americans do!
        
             | preisschild wrote:
             | For Canada we can rename the EU to just "the Union" or even
             | "The United States" :)
        
         | JLemay wrote:
         | I mean it sounds great for materials extraction, but I'm a bit
         | skeptical on infrastructure that will make long-term
         | exploration and a lunar economy actually viable
        
         | saubeidl wrote:
         | ESA is leading the way in a bunch of space stuff - we're not
         | great at launchers, but the stuff we send up is top-notch.
         | 
         | There's Euclid, which maps out the visible sky in insane detail
         | [0]
         | 
         | There's Galileo, which provides much higher accuracy than GPS.
         | (20cm vs 5m!)
         | 
         | And then there's Copernicus, which provides open-access Earth
         | Observation as a public good.
         | 
         | [0] https://www.youtube.com/watch?v=86ZCsUfgLRQ
        
           | snickerbockers wrote:
           | >There's Galileo, which provides much higher accuracy than
           | GPS. (20cm vs 5m!)
           | 
           | Very ironic name for a group of satellites orbiting the
           | earth.
        
       | BigChemical wrote:
       | The Moonlight programme is one of those low-key projects that
       | could end up being essential. Reliable navigation and comms
       | around the Moon turns exploration into long-term infrastructure.
       | It's less about planting flags, more about making the Moon
       | actually usable.
        
       | jcfrei wrote:
       | I mean, kudos to ESA for already thinking about connectivity on
       | the moon. But maybe a bit more pressing would be the launch of
       | IRIS2, so we get at least sovereign satellite based
       | telecommunications in Europe. It's set to launch with the first
       | rockets in 2029 but the full budget post 2027 hasn't even been
       | approved yet.
        
         | verzali wrote:
         | IRIS2 is a European Union project, not an ESA project.
         | Different organisations, purposes, and countries.
        
           | preisschild wrote:
           | Thats not really true. IRIS^2 is a joint project between the
           | EUSPA and ESA
           | 
           | > The European Space Agency (ESA) is responsible for
           | development and deployment of the system and the European
           | Union Agency for the Space Programme (EUSPA) is responsible
           | for the governmental service provision.
           | 
           | The ESA wants to be the "space agency" of the European Union
           | anyways
           | 
           | https://en.wikipedia.org/wiki/IRIS%C2%B2
        
       | delijati wrote:
       | Delta-V or better the second book critical mass from Daniel
       | Suarez.
        
       | ragebol wrote:
       | The navigation part will be of great use to landers there, I've
       | heard too often that the ground sensing radars lock on too late
       | to help guide the landing. Getting a good location estimate might
       | relieve some of that pressure.
       | 
       | For recent landers also didn't really know where exactly they
       | landed, only after getting spotted in images taken from orbit
        
         | sandworm101 wrote:
         | No. It is a fundamental data problem relating to sensor
         | accuracy/precision. They are called "suicide burns" for a
         | reason. Start the burn too late and you run out of time and
         | smash into the ground. Start too early and you run out of fuel
         | and smash into the ground. So you need a sensor with error bars
         | similar to your safety window for the planned burn.
         | 
         | Let's say you need to start the burn within a +/-10m box to
         | come to a stop 1 to 21m above the moon surface. You want a
         | sensor with something at least 10m precision but preferably
         | more like 1m. That would be the radar. But then say you have
         | something like a GPS with +/-100m precision. Does that help?
         | Your safe window is somewhere inside that 200m but you cannot
         | be sure where until the radar comes online. So do you use the
         | +/-100m info from the GPS? Do you maneuver to center yourself
         | inside its error bars? All you can be sure of is that you are
         | somewhere within that 200m and are 95% sure you are not within
         | the 10m window. So you make a maneuver anyway. Are you now in
         | any better an information position? No. You are still somewhere
         | in the 200m box and are still very likely outside the 10m box.
         | Heck, you might have been inside the 10m box and just moved
         | yourself out of it. You just wasted fuel. The only logical
         | thing to do is to ignore the GPS and wait for the
         | better/actionable information from the radar. The GPS may give
         | you a warm fuzzy but it doesn't actually help when you only
         | have one shot at the burn.
         | 
         | (This problem is mirrored in areas like missile guidance.
         | Running parallel sensors on a missile sounds like a good idea
         | but in reality leads to confusion, wasted energy/range and
         | reduced chance of getting to the target.)
        
           | jvanderbot wrote:
           | Not that I doubt your conclusions necessarily, but isn't this
           | what sensor fusion is _for_? You can cast it as sensor
           | "selection", which is fine, but given two sensors that show
           | 10/1 accuracy (variance 100:1), and the estimates are
           | consistent, I don't know why you'd expect it to have
           | divergent results. (Am I understanding the problem here?).
           | Your pos/alt is still measurable but with big old error bars
           | until the precise sensors kick in.
        
             | nullhole wrote:
             | That's roughly my understanding.
             | 
             | Worth noting too that your original, pre-LPS[1]
             | position/orientation/trajectory is coming from other
             | sensors with their own error bars, namely your IMU and
             | whatever information the ground can glean from radio
             | signals.
             | 
             | If your LPS accuracy is better than your IMU accuracy, I
             | don't see why it wouldn't make sense to start using it once
             | it's available.
             | 
             | [1] gotta call it something and GPS doesn't really fit
        
             | sandworm101 wrote:
             | You can only fuse sensors that are online. In the recent
             | crashes the radar wasn't. The point is that you cannot swap
             | out a high accuracy sensor, not when doing suicide burns
             | with zero margin.
        
           | ragebol wrote:
           | My case was about not having radar at all. Having GPS could
           | buy you some time and start braking already based on GPS even
           | if the radar is still out. Yes, might burn some additional
           | fuel but burning too late sucks harder I suppose.
           | 
           | Also: even tough I couldn't find anything about the
           | navigation (or rather localization?) accuracy of the
           | Moonlight system, I'd expect it to be better than 100m, but I
           | have nothing to confirm or deny this.
        
       ___________________________________________________________________
       (page generated 2025-07-17 23:00 UTC)