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Space

SpaceX's Starship Launches and Again Crashes in Test of Prototype (nytimes.com) 81

On Tuesday, a test flight of SpaceX's Starship, a huge next-generation spacecraft that Elon Musk, the founder and chief executive of the private rocket company, dreams of one day sending to Mars, came to an explosive end. From a report: That brief flight, to an altitude of about 6 miles and then back to a landing pad, appeared to again demonstrate how the mammoth rocket would tip over on its side as it descended in a controlled belly flop back toward a landing. But when the prototype fired its engines to right itself back to a vertical orientation, it appeared that one engine did not properly ignite, and Starship hit the ground at an angle, disintegrating in a fireball, leaving a cloud of smoke rising over the test site, which is in Boca Chica, Tex., near Brownsville. The end was similar to the last test flight in December which also ended in an explosion at landing, although the particular cause of the rocket failing to slow down enough may have been different.

This time, however, SpaceX at least had the permission of government regulators. Last week, SpaceX and the Federal Aviation Administration, which regulates rocket launches, seemed to be in a strange regulatory standoff. SpaceX had filled the propellant tanks of this prototype of Starship -- its ninth one -- and looked ready to launch. But then the rocket stayed on the ground when no approval from the F.A.A. arrived. Mr. Musk expressed frustration on Twitter, describing the part of the F.A.A. that oversees SpaceX as "fundamentally broken." Mr. Musk wrote, "Their rules are meant for a handful of expendable launches per year from a few government facilities. Under those rules, humanity will never get to Mars." Late on Monday, the F.A.A. gave permission for Tuesday's launch, but then added that the December launch had occurred without the agency's approval. SpaceX had requested a waiver to conduct that flight even though it posed a greater danger to the public than allowed by regulations. The F.A.A. denied the request. SpaceX defied the ruling and launched anyway.

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SpaceX's Starship Launches and Again Crashes in Test of Prototype

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  • by future assassin ( 639396 ) on Tuesday February 02, 2021 @04:05PM (#61020836)

    are belong to us.

  • by MerlynEmrys67 ( 583469 ) on Tuesday February 02, 2021 @04:13PM (#61020878)
    I know Mr. Musk is a big Linux user... wondering how the flight control software on this is written.
    • by cusco ( 717999 )

      You don't use consumer software to control hardware that may need millisecond response times.

      • by account_deleted ( 4530225 ) on Tuesday February 02, 2021 @04:47PM (#61021030)
        Comment removed based on user account deletion
        • by Tough Love ( 215404 ) on Tuesday February 02, 2021 @05:55PM (#61021346)

          GP almost got it right.. You don't use non-realtime software to control hardware that requires millisecond response time, or more realistically, microsecond. And the Linux, kernel reliable as it is, is still way too complex for critical systems. This kind of control system is always implemented with a far simpler real time control system, often not much more than a scheduler and a few drivers.

          No doubt there are multiple instances of Linux running on board the beast, but not for real time control. Things like video compression or telemetry which, while important, have far looser latency requirements than controlling engines or control surfaces.

          And yeah, referring to Linux as "consumer grade" is just plain dumb, as the reality is, Linux not only runs the majority of smart consumer appliances, it runs the whole world, including multiple $trillions of online enterprises and essentially all the world's supercomputers.

          • If you're using software in a closed loop control system, it isn't just interrupt service latency, although you are correct that that it is important; interrupt response consistency is also very important. Always being able to service an interrupt within a known, predictable time.
      • by tbird20d ( 600059 ) on Tuesday February 02, 2021 @06:30PM (#61021504)
        Spacex is a big user of Linux in their rockets and satellites. As of a few months ago, there were already over 32,000 instances of Linux running on StarLink, with an estimate that there will be over 2 million in a few years. Source: https://zd.net/30kdr4y [zd.net] The real-time version of Linux they are using may or may not be running the hardware control on Starship, but I'm not sure "consumer software" is a good description of Linux these days.
    • Re: (Score:2, Funny)

      by Anonymous Coward

      I know Mr. Musk is a big Linux user... wondering how the flight control software on this is written.

      I heard they were using a beta version of systemd-landd.

    • by simlox ( 6576120 ) on Tuesday February 02, 2021 @06:25PM (#61021480)
      They do run Linux. With preempt-realtime it is a fine RTOS. However, they also use FPGAs. Then you can run control loops safely at 100 Mhz with nanosecond precision, if you wanted to. And you can code high level stuff, and do complex math, in FPGA.
    • I thought Musk was a Windows fanboy.

  • by sconeu ( 64226 ) on Tuesday February 02, 2021 @04:15PM (#61020888) Homepage Journal

    It wasn't an Earth-shattering Kaboom...

  • by Dan East ( 318230 ) on Tuesday February 02, 2021 @04:20PM (#61020906) Journal

    It looks like it might have been the same problem as last time, which is low fuel pressure after the rocket performed the flip to orient the engines downward.

    In addition to the main two large fuel tanks used for ascent, which comprise the bulk of the volume of the ship, there are two smaller tanks used for landing. The fast flip from horizontal flight to vertical orientation for landing causes any remaining fuel in the big tanks to slosh around severely, so it can't feed properly to the engines. The smaller tanks are full, so the fuel should feed out of them as desired.

    After the last failed landing (SN8), SpaceX made some changes to remedy the low pressure issue, but that may not have worked. Since SN9 (which flew today) was mostly built, SpaceX may have had to do a more superficial modification to try and fix the problem, instead of more significant engineering to the tanks / feed system. SN10, which is already at the launch pad awaiting its test flight, could have more fundamental changes to fix the problem.

    Or it could have been something else entirely.

    • Since one engine was operating normally it seems unlikely to be low fuel pressure.
    • by crow ( 16139 )

      It looked to me like it just didn't get oriented correctly in time. But what do I know? I'm just some guy watching the video. In any case, I hope it's something different so that they learn about another failure mode and can fix it.

    • by monkeyxpress ( 4016725 ) on Tuesday February 02, 2021 @04:40PM (#61020998)

      Seemed to me that one of the engines lit fine and was producing thrust until impact, but the other just failed to light. Quite different from the other failure as the engine didn't start eating itself as it leaned out on propellant - it just didn't light at all. This would suggest the header tanks were working okay, but the issue was with the engine itself.

      If you look at the landing profile you can see the control system trying to operate from a single engine's thrust, which results in it over-rotating on the flip and running out of time to bring the rocket back to vertical. In the first test, because both engines produced thrust during this phase, the flip and deceleration were better.

      It must be a bit painful having to eat the cost of three Raptors every time this test fails. They'll be hoping that SN10 can get the issue sorted, otherwise it might be prudent to put some chutes on it and test the flip/relight at higher altitude (with a landing on water/chutes) until they iron out the issues.

      • by Dr. Spork ( 142693 ) on Tuesday February 02, 2021 @05:00PM (#61021102)
        My apartment building has 17 floors. It's the same height as sn9. Objects that size can't use parachutes. If the second engine ignited, I'm confident it would have landed. To me it looked like a lack of oxygen this time. But I wonder if it would make sense for the third engine to fire up and gimbal if one of the other two has problems. It would be good to have a spare just to shed velocity. They could have at least brought it to hover, something that Falcon 9 cannot do but Starship can, even with two working engines.
        • by reg ( 5428 )

          To me it looked like a lack of oxygen this time.

          The oxygen header tank is in the nose and clearly had a lot left (the white clouds in the images).

          • That doesnt mean the engine cant be starved of it for many reasons - blockage in the line, failure to switch over to the alternative supply for landing etc etc

      • by lazarus ( 2879 )

        I'm confused (as usual). I thought that none of these prototype rockets were designed to land successfully. They have no legs and the plan is to eventually "catch" them with the launch tower when they return.

        The problems with the failure of an engine to light notwithstanding, won't they all explode upon landing until they get their new landing system developed and perfected?

        • by reg ( 5428 )

          I'm confused (as usual). I thought that none of these prototype rockets were designed to land successfully. They have no legs and the plan is to eventually "catch" them with the launch tower when they return.

          These are the second stage of the rocket, which's designed to go to mars and to return from orbit. SN9 did have legs, just short stubby ones that flip out just before landing. These same legs were used on SN5&6 and worked OK.

          The first stage (known as Super Heavy, or the booster) will be much bigger and will never go to orbit. It will launch and land much like the current Falcon 9, although there's now talk of it landing back on the pad and being caught.

        • Starship is the orbiter and is designed to land on legs (they are folding ones which drop down from inside the skirt on these test vehicles). What launched today was a Starship test article, SN9.

          Super Heavy is the booster and is what SpaceX are referring to when they talk about it being caught by the launch tower. We haven't yet seen a Super Heavy in the wild, let alone had a test launch.

        • They are also the test bed for learning to land on raptors, which the booster will do eventually (although maybe getting caught by a gantry or whatever) and starship is supposed to do for things like long distance ballistic flights and mars missions.

      • by reg ( 5428 )

        It must be a bit painful having to eat the cost of three Raptors every time this test fails.

        They're pretty much eating that cost anyway until the engines are perfect, which they clearly are not. But that was a $10mil+ explosion, which is like $40 of net worth to the average American...

    • From my armchair, it looked like chunks of something fell out of the skirt area around the engines shortly after re-ignition. Guessing a pre-burner burped and asploded on the second raptor.
    • by iikkakeranen ( 6279982 ) on Tuesday February 02, 2021 @04:59PM (#61021098)

      One of the two engines used for the landing failed to ignite. Something broke with enough force to send debris flying out when it was supposed to start.

      With just one engine there was not enough thrust to control the orientation or slow down enough. The vehicle overshot the flip maneuver, ending up "on its back" in a roughly 45-degree angle to the ground as it fell.

      There's a great video here [youtube.com]

      • Yeah, it looked like a hard start (aka, the fuel in the bell exploded rather that a smooth burn at first). I'm curious as to whether that's because something broke earlier, or the hard start broke things. (ex: a turbo pump might have let go/had an internal explosion when re-light was attempted)
        • Re: (Score:3, Interesting)

          If you watch it going up, one of the engines had red --the color of "engine rich" -- exhaust. So something broke earlier.
  • by Thud457 ( 234763 ) on Tuesday February 02, 2021 @04:22PM (#61020918) Homepage Journal
    "Megalomaniac Billionaire Launches Missile Attack on Earth"
    TFTFY
    • It botth launched and crashed again, so:

        "SpaceX's Starship Launches and Crashes Again in Test of Prototype"

      And, given this was not the same Starship that crashed previously, and we know it launched:

          "Another SpaceX Starship Prototype Crashes on Landing"

      • This is trouble with the headlines... over in YRO they're talking about SpaceX's StarLink as the solver of Internet freedom problems, but over here they're having trouble landing their space transport system...

  • Is it high time already to buy yourself a country? Or at least an island... with a dead volcano for a covert launch site ;)
  • Comment removed (Score:4, Interesting)

    by account_deleted ( 4530225 ) on Tuesday February 02, 2021 @04:51PM (#61021056)
    Comment removed based on user account deletion
  • Maybe next time: (Score:5, Insightful)

    by A10Mechanic ( 1056868 ) on Tuesday February 02, 2021 @05:02PM (#61021110)
    Maybe next time don't park SN-10 right next to where you expect SN-9 to crash.
  • awesome progress regardless!
  • Last week ... Musk expressed frustration ... describing the ... F.A.A. ... as “fundamentally broken.”

    Which ironically mirrors the status of the Starship's software.

    • Software is not what causes an engine to blow up on attempting to re-light. Raptor engines have proven finicky so far, lots of static fire issues with lighting them. They are, of course, a novel engine design which is still being developed.

      • 1. Hey. I worked in the disk-drive biz for 25 years. The purpose of software is to provide work-arounds for defective hardware.
        2. The designers of the software in this case failed to consider that when the Starship suddenly changes attitude the density of the fuel entering the engine has drastically changed.
  • One has to admire Elon Musk for bringing rocket science into the new millennium. This is the first viable prototype where the same rocket motors are used for launch and landing without chute or wheels. All previous rocket motors used for landings were not the same launch motor. Even the Apollo LEM had separate motors for landing then launch. So this is real innovation, taking a controlled explosion off of the launch pad then using the same launch system to fire a controlled explosion to land. Its not like
    • You are right that SpaceX made this innovation, but not for Starship. Falcon 9â(TM)s first stage lands with the same Merlin engines that it launches with, and they have perfected the maneuver with that vehicle to the point of it being as mundane as the landing of a 727 jet.

    • by mvdwege ( 243851 )

      Yes, it is nice to see that when Musk's engineers finally have to do something new instead of refining 70s tech, it suddenly turns out that all those government engineers weren't morons, rocket science is actually hard.

      • Saturn V, 7 Million pounds of trust, Zero to Mach 4 in under 4 minutes, all running on less technology and computing power than a single smart phone. And we never blew one up. That is Rocket Science!
  • by photonrider ( 571060 ) on Tuesday February 02, 2021 @06:00PM (#61021364)
    Wait a second, how did the first site pose a grater danger to the public than the second one? Same flight parameters, same location? Was the wind blowing in an unfavorable direction the first time? I doubt it was something like that, the FAA rep would need to be onsite or immediately available to give the go no-go.
    • Musk is speeding right through these no-go's... so the FAA needs to turn this over to the FBI.

      • We do not need to live in a totalitarian world where everything is illegal and you need government permission slips to do anything; that's the opposite of the nation our founders handed us.

        Musk did not endanger ANYBODY with either flight. His flights occurred entirely over land he owns, coastal waters of the US, and possibly (I have seen no telemetry data) international waters - with those waters being cleared of people before the tests.

        Frankly, with these conditions, our founders would be astonished that t

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