back to article CAPSTONE mission is Moon-bound, after less rocketry than expected

NASA and commercial space outfits Rocket Lab and Advanced Space have collectively announced that the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment – CAPSTONE – mission has left Earth orbit and is on its way to Luna. The CAPSTONE mission plan called for the satellite to launch from New …

  1. SminkyBazzA

    Did it go better than expected because they forgot to attach some pieces? I was under the impression that anything involving trajectories in space was heavily simulated before launch, so it concerns me (the uneducated lay person) that anything unexpected can happen without something having gone "wrong".

    1. Martin-R

      I think it's more "went righter" than "went wrong". They will work to a range of outcomes from each burn and eight will (probably?) have been the worst case. If you look at the JWST coverage, they ended up with a lot more fuel for station keeping than the 10 year baseline thanks to a very precise launch and mid-course burns - see

    2. Persona Silver badge

      Whilst the orbit has been simulated to the nth degree, pointing the rocket in precisely the right direction during an engine burn is always subject to some error. You only need to be out by a minute fraction of a degree for that to make a very big difference as you travel hundreds of thousands of miles. This error then leads to different gravitational interaction so in time the orbit and the simulation diverge even more.

      1. SminkyBazzA

        Thank you very much for the explanation, I knew there must be a reason (hence my use of quotes around my implication that something went wrong) but I didn't know where along the line the divergence would have crept in.

  2. AlgernonFlowers4

    Touching Cloth?

    What exactly is a near rectum liner hello orbit?

    1. Andy The Hat Silver badge

      Re: Touching Cloth?

      I don't believe that's useful unless you plan a mission to Uranus

    2. 42656e4d203239 Silver badge

      Re: Touching Cloth?

      it's an orbit that swooshes around the bowl but never quite gets sucked down into the gravity well - though it does need a boost every now and again!

    3. DevOpsTimothyC

      Re: Touching Cloth?

      I hate to think what a rectum orbit might involve, but a near rectilinear halo orbitcan be described by it's constituent words.

      An orbit is where something goes around and around, typically in a circle. As the orbit gets more eccentric it goes from a circle to an oval to an ellipse, finally to rectilinear (out and back in a single plane). so a near rectilinear orbit is one where alot of time is spent "out" in orbit with very little time "near" the body it's orbiting (in this case the moon).

      A halo orbit is one which goes through, or is very close to the a Lagrange point. A Lagrange point is where gravitational forces balance out. From memory there are 5 Lagrange points in any orbiting system. If you draw a line out from the larger body (the earth in this case) through the smaller body (the moon in this case) the two orbiting bodies one is on the line between the two (closer to the smaller one), another is on the other side of the smaller body, two are at 90 degrees to that line before and after the smaller body on it's orbit and the final one is on the same line, but on the far side of the larger body.

      So a near rectilinear halo orbit is one that is an elipse with one end near the moon and another by one of the Lagrange points. From the Earth's perspective the orbit is flat so we can always see (communicate with) the satellite, think you're drawing an elipse with a laser pointer around something on the wall on the other side of the room. You would be the earth, the thing on the wall would be the moon and the elipse is the near rectilinear halo orbit. If you look at the orbit from afar it looks similar to the ridges on the paper hats you get out of Christmas crackers.

      As the thing they want to orbit is on the south pole of the moon, the satellite spends most of the time over that spot with very little time (a few hours) out of site from there. The base on the moon can then use the satellite as a relay station to earth.

    4. John Robson Silver badge

      Re: Touching Cloth?

      Scott Manley's explanation

      Basically near rectilinear means it's *really* elliptical, about as far away from a circle as you can get without the lunar surface getting in the way - it's nearly a straight line in, then out...

      Halo orbit, it's actually orbiting part of the Earth Moon gravitational system, not just the moon.

      It's a clever orbital position, theoretically really nice for a variety of reasons... This mission will confirm a bunch of those

    5. Persona Silver badge

      Re: Touching Cloth?

      In reality the orbit is scientifically clever rather than biologically concerning.

      Scott Manly explains how it works here

  3. Joe W Silver badge

    The article in "BILD"

    Well... that taboid might occasionally and accidnetally contain a grain of truth (the football results from the weekend, I guess), but here I find it more likely that they got their statement from NASA administrator Bill Nelson's dog, and maybe not the dog's mouth... I'd take that with a grain of salt and a fistfull of chilli powder.

    1. Anonymous Coward
      Anonymous Coward

      Re: The article in "BILD"

      Joe W,

      Much like 'The Sun' in the UK .... but with 'fwer spleing mistackes' !!!


      1. TeeCee Gold badge

        Re: The article in "BILD"

        Actually more like the Sport...

        Maybe they'll find that WWII bomber that the Sport reported to be there...and then that it mysteriously disappeared, generating two front page headlines with only one bit of bullshit.

    2. brainwrong

      chinese rebuff

      ' Chinese foreign ministry spokesman Zhao Lijian responded by calling the remarks "a smear campaign against China's normal and reasonable outer space endeavors."'

      That doesn't look like a denial from the chinese, whatever the reality of Bill Nelson's words.

      Not that they could defend the moon from invasion by american missions, anyway.

  4. Simon Harris

    NASA boffins will spend months nudging CAPSTONE.

    Is there a point at which boffin time and associated infrastructure becomes more expensive than putting a bigger rocket on and getting it there faster?

    1. GrahamRJ

      Re: NASA boffins will spend months nudging CAPSTONE.

      Almost certainly - but $5m buys a lot of boffin time. And with the rocket equation being what it is, price goes up exponentially as the fuel load gets bigger.

    2. Anonymous Coward

      Re: NASA boffins will spend months nudging CAPSTONE. UPDATE

      Boffin time is being used to test the NRHO.

      Eventually, this orbit will be used by the NASA Lunar Gateway with the first, much larger, component being launched atop a SpaceX Falcon Heavy.

      A six pack for the boffins for getting it there in six burns.

      UPDATE: NASA Ames reports that boffins have lost contact with CAPSTONE and are investigating.

      1. ricardian

        Re: NASA boffins will spend months nudging CAPSTONE. UPDATE

  5. DrBobK


    Why 'Luna' and not 'the moon'?

    1. WhereAmI?

      Re: Luna

      'Luna' specifically refers to the moon that orbits Earth, as opposed to (say) Phobos which is a moon of Mars.

      1. Stork Silver badge

        Re: Luna

        As a non-native user of English, I thought the same could be achieved by writing “the Moon” rather than “the moon”.

        Feel free to educate me.

        1. Olafthemighty
          Thumb Up

          @ Stork

          You're absolutely right, and I think that would be more common. Luna is maybe more sciencey..?

          1. Irony Deficient Silver badge

            Luna is maybe more sciencey…?

            “Luna” is a proper noun, like “Terra” or “Venus”, from the Latin word for “moon”. It is of course a component of other words, like “lunar” and “lunatic”. The Greek equivalent is “Selene” (from Σελήνη), which is a component of “selenology” and “selenography”.

            “Luna” is a name; “the moon” is a noun phrase. “The Moon” is both a name and a noun phrase, but “Luna” has the advantage of brevity since it doesn’t require an article in English.

            1. dajames

              Re: Luna is maybe more sciencey…?

              “Luna” has the advantage of brevity since it doesn’t require an article in English.

              On the contrary, "The Moon" has the advantage of brevity, as it doesn't require a comment-storm of explanation every time it is used.

              ... oh, and “Selene” isn't "from Σελήνη", it's just the same thing written in a different alphabet.

  6. Lord Elpuss Silver badge

    "Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment – CAPSTONE"

    Backronyms suck BALLS (Bastardised Artificial List of Lots of Synonyms). Just call it CAPSTONE (cool name) and forget the manufactured bollocks that it supposedly 'stands for'.

    1. Stork Silver badge

      First law of projects: you need at least one cool acronym.

      1. TimMaher Silver badge

        Cool acronym

        And then you can move on to other projects like... like... Treadstone and Blackbriar?

        1. Aussie Doc

          Re: Cool acronym

          You are Jason Bourne and I claim my $5.

          So I can buy one of these -->

          1. Lord Elpuss Silver badge

            Re: Cool acronym

            $5 beer money won't go far these days...

            1. Swarthy

              Re: Cool acronym

              They did say to buy one.

      2. dajames


        First law of projects: you need at least one cool acronym.

        Well, Camping Out On Luna sounds pretty cool to me, let's just leave it at that one, shall we?

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