back to article ULA nears second launch of Vulcan Centaur in pursuit of US Space Force approval

United Launch Alliance's (ULA) Vulcan Centaur is ready to blast off from Florida this morning, the second flight to space for the rocket. While the mission, dubbed Cert-2, was originally set to carry Sierra Space's Dream Chaser, delays with the spaceplane have meant that ULA opted to lift-off with an inert payload instead. …

  1. S4qFBxkFFg
    Unhappy

    After giving up the wait for Dream Chaser, which should arrive at some point in 2025, ULA is instead going to use a mass simulator along with some experiments and demonstrations to ease the vehicle's passage to US Space Force certification.

    I have an (excessive?) dislike for this term: unless there is new physics involved, it doesn't simulate mass, it IS mass. It's like referring to an airworthy aircraft as a flight simulator.

    My apologies to ULA if it is actually a very small box with several sets of switches and dials on the side, with labels "inertial", "passive gravitational", and "active gravitational".

    (The term "inert payload", further up the article, is better.)

    1. Tim_the_Unenchanter

      The correct term would be payload simulator, or perhaps inert payload - since it is dead weight taking the place of a useful payload….

      1. Bitsminer Silver badge

        Well, apparently no inert electric vehicles were launched into solar orbit either.

    2. Gene Cash Silver badge

      > It's like referring to an airworthy aircraft as a flight simulator.

      No. If it was an airplane, it wouldn't have engines, wings, landing gear, fuel tanks, or even a place to sit. It wouldn't even be airplane shaped.

      The only thing it simulates from a real payload is the mass, thus the name. It does not simulate any other bits, such as the size, shape, electrical characteristics, or fluid dynamics.

      It's basically a block of metal with some struts to bolt it on, and probably some things to record vibration, sound levels, and accelerations.

      "Inert payload" is not quite right either, as it's not a payload; it installed in place of a payload and doesn't actually accomplish any function or separate from the rocket.

      1. ACZ

        So "payload mass simulator"?

        1. collinsl Silver badge

          Or "Supported High Inertial Testload - Heavy Equipment APproximator"

    3. jdiebdhidbsusbvwbsidnsoskebid Silver badge

      I always interpreted mass simulator not to mean simulated mass, but some mass that is a simulator (for a real payload).

      A bit like "near miss" doesn't mean nearly a miss, but a miss where things were near (to each other).

  2. GDM
    Mushroom

    Littering

    to take the upper stage and its inert payload to deep space and into an orbit around the Sun.

    So having figured out that littering earth orbit is bad, we're going to spin junk around the rest of the solar system instead? Or is it heading into the sun and will provide spectacular effects for some yet to be announced rock concert? Good job space is really, really big anyway. I hope there's a set of hazard warning lights at least.

    1. Richard 12 Silver badge

      Re: Littering

      It'll likely impact the Earth in a few years.

      By "heliocentric", they mean "following the Earth pretty closely", as it was given the final bit of delta-v very near Earth.

      After a few orbits (years) it'll come close by again, and eventually it'll either hit Earth, or steal momentum from Earth and get kicked out of the solar system.

      If we're unlucky, it'll steal a load of momentum one year then give it all back in a few seconds a few years later.

      1. Bill Gray
        Megaphone

        Re: Littering

        Objects of this sort usually end up in "earth-like" orbits. This means we see them every few decades; after, say, 31.6 years, we've gone around the sun 31.6 times, the object has completed 30.6 or 32.6, and we catch up to one another again. And almost certainly miss each other.

        Closest comparison I can give (and it's a good one) is to lunar ejecta, bits knocked off the moon by asteroids. An example is 2024 PT4, which got a write-up on El Reg recently. Such rocks have a mean lifetime of tens of thousands of years, after which they hit the earth or the moon. (They don't have enough energy to make it to Venus or Mars, much less any other planets.)

        In this case, the orbit for the Vulcan Centaur and its payload are secret. No, I kid you not, and some of us astronomers are not happy about this. The odds are good that this particular object will be picked up by the asteroid surveys and the orbit announced whether ULA likes it or not (this has happened for two previous "secret" launches, for Peregrine and KuiperSat). But it's a hell of a way to run things. Hence the shouty icon.

    2. Anonymous Coward
      Anonymous Coward

      Re: Littering

      Hitting the sun is really hard to do. You have to counter earth's velocity around the sun (107000 km/h), otherwise you just end up orbiting the sun. Though it's actually decelerating relative to the sun, it's all just delta-v (change in velocity) and that's about 4 times the delta-v you need to get into orbit.

  3. Richard 12 Silver badge

    They didn't wait until "the last minute"

    The last minute is the point where you've still got time to integrate a new paying payload.

    They waited until it was already too late, and had to launch a lump of (presumably) concrete.

    1. PerlyKing
      Black Helicopters

      Re: launch a lump of (presumably) concrete

      Or is it a double bluff and they've just launched a super-ultra-secret payload?

      1. Phil E Succour
        Joke

        Re: launch a lump of (presumably) concrete

        Or maybe Dean Wormer's involved, and it's a double-ultra-secret-payload.

  4. beast666 Silver badge

    Vulcan suffered a serious failure during this flight. The nozzle on one of the SRBs exploded.

    You'd think the Americans would be sensitive to SRB anomalies.

    1. Jellied Eel Silver badge

      Vulcan suffered a serious failure during this flight. The nozzle on one of the SRBs exploded.

      Depends how you define 'serious'. On the plus side, it still managed to get the payload where it was supposed to be. On the minus, it blew off the nozzle from one of the SRBs. Which I think is a testament to advances in space flight that the malfunction wasn't as serious as it could have been.

      1. Gene Cash Silver badge

        Well considering how simple solid rockets are, any failure is serious. They're like hammers: you've got a handle and a lumpy part, so there's not much to break, and when it does, there's not any "graceful degradation of function" - it's broke.

        Since the usual failure mode of a solid is "instantaneous boom" they got lucky somehow.

        The mission was basically "make it to orbit without any failures" so that's a big nope there. We'll see how squinty-eyed the DoD is about it. I'll bet they'll require another launch, possibly with Dream Chaser, before approving it.

        Edit: this is usually how it goes https://www.youtube.com/watch?v=mTmb3Cqb2qw

        1. Jellied Eel Silver badge

          Well considering how simple solid rockets are, any failure is serious. They're like hammers: you've got a handle and a lumpy part, so there's not much to break, and when it does, there's not any "graceful degradation of function" - it's broke.

          Since the usual failure mode of a solid is "instantaneous boom" they got lucky somehow.

          Yep, Scott Manley had a video discussing this. It'll be interesting to see what info ULA got from telemetry, or if they could recover any of the SRB to inspect it. But still pretty impressive that there was no boom and the spacecraft was still able to make the planned orbit, despite losing a chunk of the SRB and some thrust.

      2. Oneman2Many Bronze badge

        It was more luck than design that the rocket didn't suffer a RUD. But well done that it still made it to orbit.

    2. itsborken

      It's more of a scandal that they didn't push the destruct when the motor's nozzle ring blew off. Does NASA now fly on the hope that it holds together enough to make it to the next stage? Boosters cannot burn into the booster stage?

      1. Dvon of Edzore

        No Boom Today

        Didn't match the criteria for either automated or manual destruction, mostly because the rocket remained under control and did not depart from the flight corridor. ULA got very lucky here.

  5. Hizoomi

    I can't believe The Register wasn't the news source to refer to this problem as a "strap-on booster anomaly"

    https://spaceflightnow.com/2024/10/04/ula-launches-second-vulcan-flight-encounters-strap-on-booster-anomaly/

    1. diodesign (Written by Reg staff) Silver badge

      Strap-ons

      Been there, done that ;-)

      C.

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