[HN Gopher] SpaceX SN9 Explodes on Landing
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       SpaceX SN9 Explodes on Landing
        
       Author : beervirus
       Score  : 170 points
       Date   : 2021-02-02 20:35 UTC (2 hours ago)
        
 (HTM) web link (twitter.com)
 (TXT) w3m dump (twitter.com)
        
       | 6nf wrote:
       | Another amazing test flight! Can't wait for SN10. I understand
       | they have already started the last step of construction which is
       | fitting the Raptor engines to SN10. Should be ready to fly very
       | soon.
        
         | GizmoSwan wrote:
         | You loved the quality of the explosion. Did you?
         | 
         | Bigger the explosion, the more promising is the venture! NOT
        
       | batterylow wrote:
       | Explosion happens just after 12:45... I'm sure they've collected
       | useful data.
        
       | joshxyz wrote:
       | Woops unscheduled disassembly <3
       | 
       | SN10, we're waiting!
        
         | Leparamour wrote:
         | >Woops unscheduled disassembly <3
         | 
         | The one where the front fell off?
         | 
         | https://www.youtube.com/watch?v=3m5qxZm_JqM
        
       | hikerclimber wrote:
       | nice! hopefully we have more spaceships which explode and china
       | and russia beat us to space.
        
       | hyperion2010 wrote:
       | For both SN8 and SN9 my brain is screaming at me "surely they
       | need more than 3 engines?!" Is the ultimate expectation that the
       | engines will never fail, because it sure seems like they can't
       | deal with losing even a single engine. I'm sure this is
       | completely incorrect given that the issue for SN8 was tank
       | pressure.
        
         | walrus01 wrote:
         | It's my understanding currently that a 'production' starship
         | will have three central engines optimized for sea level, and
         | additionally three vacuum-optimized engines installed around
         | its inside base perimeter.
        
       | d_silin wrote:
       | Illustration how "move fast and break things" in aerospace domain
       | works.
        
         | ericd wrote:
         | Honestly, my main takeaway from this testing and Falcon 9 dev
         | has been that we should be doing a whole lot more of that than
         | we have been, at least until there are human passengers. The
         | contrast in rate of progress with eg SLS is stunning.
        
           | Already__Taken wrote:
           | We knew this since watching how much the Russians got done in
           | the time they had for the resources. Put the engineers
           | together with the manufactures, build often, test more.
        
           | codefreakxff wrote:
           | Well. Yes. It appears to be a fully functioning launch
           | vehicle and just as reusable as its predecessors, don't see
           | much downside in making the landings more "interesting". When
           | they work out the dynamics of it then they really have
           | something that will revolutionize launches
        
           | api wrote:
           | Also keep in mind that it's already doing what pre-F9 rockets
           | did: go up. The RUDs so far are on landing attempts. Landing
           | is a whole lot harder.
        
         | walrus01 wrote:
         | They landed a lot of falcon 9 first stages without legs on the
         | water, vertically, to test the control system. And a number of
         | attempted barge landings with legs failed, before the first
         | successful landing. Now it's almost a routine thing.
        
         | MR4D wrote:
         | 'We may crash, but at least we do it with style!"
         | 
         | Somehow that should be an Elon tweet.
        
           | jerf wrote:
           | If you happen not to have seen it, "How Not To Land an
           | Orbital Rocket Booster":
           | https://www.youtube.com/watch?v=bvim4rsNHkQ from SpaceX.
        
       | tectonic wrote:
       | This is why we test. (In this case, header tank helium
       | pressurization and more thermal tiles.)
       | 
       | At least they didn't hit SN10!
       | 
       | Summary tomorrow in this week's Orbital Index
       | (https://orbitalindex.com).
        
         | Florin_Andrei wrote:
         | Well, they popped a bunch of Falcon 9s until they got those
         | right.
        
       | mongol wrote:
       | I am impressed by the camera angles. How do you think they filmed
       | the last parts? With a drone?
        
       | rglover wrote:
       | Love seeing these tests for two reasons:
       | 
       | 1.) Experiencing history in the making, especially knowing that
       | the SpaceX team will eventually get it right. 2.) Realizing that
       | even the best of the best have repeated failures and need to rely
       | on iteration to get "there."
        
         | cmoscoe wrote:
         | On the 'repeated failures' piece, that's somewhat new for
         | aerospace. Traditionally, things would be over-engineered, and
         | losing a test vessel would be considered a bad thing. SpaceX
         | seems very content to blow up a bunch of rockets on their way
         | towards not blowing up rockets.
         | 
         | This seems to have caused at least part of their recent issues
         | with the FAA, who seem to be less ok with explosions. It will
         | be very interesting to see if this iterative approach leads to
         | more reliable rockets down the line!
        
       | trasz wrote:
       | I wonder what's that tiny thing that seems to have broken off
       | some two seconds before it hit the ground?
        
         | bdamm wrote:
         | Indeed, there were two. Two objects broke off from the ship
         | before impact, one just before the first swing of the pendulum
         | and one just after.
        
         | jansan wrote:
         | Also, there was an unusually large flame at the end of the
         | liftoff. Maybe that already sealed SN9's fate.
        
           | d1str0 wrote:
           | At apogee? Pretty sure that final flame is expected.
        
         | kazinator wrote:
         | I was thinking, someone's ego that was accidentally left
         | attached. But, oh, you said tiny thing. :)
        
         | kazinator wrote:
         | I was thinking, someone's ego that was accidentally left
         | attached to the fuselage. But, oh, you said tiny thing.
        
         | Gh0stRAT wrote:
         | Watching it in slow motion, it looks almost like pieces of
         | insulating foil.
        
       | Diederich wrote:
       | Failure with one of the engines on re-light:
       | https://twitter.com/MurkyWanders/status/1356703469986586626
       | 
       | "I bet they needed that."
       | 
       | As others have noted, SN10 is standing by. Somewhat uncomfortably
       | close by: https://i.imgur.com/F9rsBbD.png
       | 
       | It's so exciting to be a spectator of these events.
        
         | _Microft wrote:
         | _SN10, wenplop?_
         | 
         | The debris does not seem to come from next to the failing
         | rocket engine but from the outer wall next to the engine that
         | was not used in the landing attempt. It appears first shortly
         | before the clock shows 6:21.
        
         | Florin_Andrei wrote:
         | > _SN10 is standing by. Somewhat uncomfortably close by_
         | 
         | That was my immediate comment at the end. Pretty confident they
         | are.
        
           | 2OEH8eoCRo0 wrote:
           | This was my thought even before launch. SN9 could explode on
           | the pad.
        
         | caminocorner wrote:
         | They're definitely going to need to inspect it for damage, but
         | it does seem odd not to be THAT close
        
       | breatheoften wrote:
       | Was it camera angle that made it appear to be so perfectly flat
       | (top and bottom of rocket at same altitude) when it was in free
       | fall or was that actually the target free fall orientation?
       | 
       | I thought the top of the rocket was supposed to be slightly
       | elevated compared to the tail ... I suppose it couldve just been
       | a lack of thrust due to some engine issue -- but the motion
       | looked very unnatural when the rockets relit -- almost as though
       | too much energy was being expended to get the top of the rocket
       | lift ed ... It seems to me like the top should be slightly
       | elevated relative to the tail in free fall so that the thrust on
       | refiring will produce the desired tail swing with minimal energy
       | ...
        
         | NortySpock wrote:
         | I presume it was the target orientation since they held it for
         | so long, had they wanted to actively leave that orientation
         | earlier I assume they would have done so.
         | 
         | Especially subsonic I assume their orientation does not matter
         | a whole lot when just trying to fall with max drag.
         | 
         | Not sure how much energy they'll save doing the flip maneuver
         | earlier though, seems like they want max drag as low as they
         | can go, then flip to powered flight at the last moment possible
         | -- and their problem seems to be keeping the engines lit.
        
       | ashtonkem wrote:
       | I'm not sure if I'd call that a landing.
        
       | mempko wrote:
       | When you look at the history of the space race between Soviets vs
       | USA, one thing that is clear is the approach used by both
       | countries to engineer their craft were very different. The
       | Soviets would do design by testing and blow up many rockets and
       | gather data vs the USA which would be more up-front about it's
       | design and design testing before gong live.
       | 
       | SpaceX clearly took the Soviet's approach to rocket design.
       | 
       | EDIT: This is not a negative thing. Soyuz is pretty darn safe
       | because of the approach they took.
        
         | bobo_legos wrote:
         | Does anyone know some good books that explore the space race?
         | I've read Carrying the Fire(which was excellent), but it
         | doesn't touch much on what the Soviets were doing.
        
           | Cyphusx wrote:
           | I found "This New Ocean" by William E. Burrows to be a rather
           | good account of the first space race, as it covers both sides
           | in an equal amount of detail.
        
           | e-_pusher wrote:
           | This biography of the chief rocket designer of the Soviets,
           | Sergei Korolev, is also a good introduction to the Soviet
           | space program.
           | 
           | https://www.amazon.com/Korolev-Masterminded-Soviet-Drive-
           | Ame...
        
         | the-dude wrote:
         | Comrade! This is 2021, nothing positive about Mother Russia may
         | be mentioned on this capitalist cesspool.
        
           | mempko wrote:
           | It's funny because the Soviets did it right, in that they
           | funded smart people and gave them control. The Nasa's
           | approach was to have people create proposals and get approval
           | for funds.
           | 
           | We have forgotten that the "fund smart people and let them do
           | what they want" is the best approach. Look at Xerox Parc,
           | Bell Labs, etc. Nasa's modern approach with SpaceX and other
           | companies seems to reflect these hard learned lessons.
        
             | PeterisP wrote:
             | "fund smart people and let them do what they want" - well,
             | that's not exactly how it worked - for example, while
             | Korolov was mostly able to get the resources he needed in
             | the 1950s, in the early 1940s he did his engineering work
             | on bomber design from a prison labor camp (which is a bit
             | far from "let them do what they want" or "give them
             | control") after losing most of his teeth from malnutrition
             | during forced labor in a gold mine. This probably provided
             | a perspective for him of what the limits of "do what you
             | want" are in reality.
        
             | the-dude wrote:
             | IIRC Zhe Germans were pretty hands-off with von Braun as
             | well.
        
             | waiseristy wrote:
             | These smart people did not have any semblance of control in
             | the USSR. The Soviet space program was 95% political,
             | heavily influence by the politburo and Soviet interests.
             | Smart people would not have developed the Buran if all
             | options were on the table
        
             | rurban wrote:
             | It's more funny that both primarily used thousands of
             | Germans as their rocket technicians, and both german
             | parties used their german style, based on engineers as
             | heads.
             | 
             | This all changed with Lyndon Johnson taking over, getting
             | rid of the Germans, introducing the well known inefficient
             | NASA/gov-style management style known from the Shuttle era,
             | and moved the technicians out of Alabama to Houston. This
             | was the anti-modern democratic approach.
             | 
             | SpaceX simply went back to the old modern style, which
             | worked well for the US and Russia.
             | 
             | The trick was not using smart people, but experienced
             | engineers in control, and not fresh anti-engineer PM's out
             | of college. Everybody can control a budget, esp. engineers,
             | but only engineers can control engineering problems.
        
               | Layke1123 wrote:
               | I have watched PMs actively contribute nothing to a
               | project by entering false metrics. It really is either
               | you can build something, or you can't and contribute
               | nothing to the project.
        
         | hinkley wrote:
         | The Russians also were fond of "give it more gas", which SpaceX
         | has also embraced and Elon has called out before. The fuel is a
         | real big piece of the launch cost but it's far from the
         | largest. If your rocket equation calls for a little extra fuel
         | but in exchange you can use more reliable or at least less
         | exotic parts, just do it.
        
         | [deleted]
        
         | evgen wrote:
         | While the US had better tech and improved design they all
         | tested the shit out of things before going live and then ran
         | live tests on unmanned rockets, many of which exploded quick
         | spectacularly. Soyuz might be safe now, but that safety was
         | paid for by many near-misses and in several cases in cosmonaut
         | blood. Your statement regarding US vs Soviet approach to the
         | space race is simply wrong.
        
           | Layke1123 wrote:
           | Challenger? What's your point? That Russia didn't beat the US
           | into space? I thought the west at least accepted that fact.
           | Or do you just have to believe the US is ALWAYS "superior"?
        
           | NikolaeVarius wrote:
           | > As of 2020, there have been 15 astronaut and 4 cosmonaut
           | fatalities during spaceflight. Astronauts have also died
           | while training for space missions, such as the Apollo 1
           | launch pad fire which killed an entire crew of three
           | 
           | The numbers don't really seem to support your assertion that
           | NASA is generally much safer than Soviet/Russia
        
             | evgen wrote:
             | Both had two vehicles lost in space/reentry, the shuttles
             | just held more astronauts. In terms of percentage of fatal
             | missions the two were roughly equivalent, with Soviet
             | failures front-loaded into less sophisticated and less safe
             | early vehicles while the US failures were later on an
             | overly-complicated system design.
        
             | valuearb wrote:
             | At least 126 technicians and cosmonauts were killed by
             | accidents during the Soviet space program. It's rumored
             | that additional cosmonauts died on missions that the
             | Soviets covered up.
        
               | hinkley wrote:
               | We also lost all three astronauts in a test of the Apollo
               | capsule which doesn't count as flight but I think we
               | would agree still counts in the buckets of blood both
               | programs have spent.
               | 
               | If you do more tests which kill more people before
               | declaring the system good, you don't get to not count
               | those people like it's a different color of money in some
               | bureaucratic dystopia.
        
             | fpgaminer wrote:
             | But the U.S. has sent 3x as many citizens into space: https
             | ://en.wikipedia.org/wiki/List_of_space_travelers_by_nat...
             | 
             | So combining with your statistic the U.S. has a fatality
             | rate of 4.4% versus Russia's 3.3%. Given the low N it's
             | probably within margin of error.
        
       | Diederich wrote:
       | And that's why you have an assembly line for Starships:
       | https://i.redd.it/dmr9bjhpcee61.jpg (SN9 lacking the RUD symbol
       | in that image of course.)
        
         | 6nf wrote:
         | Also note that BN1 (which is the booster stage) is getting
         | close to completion! I wonder when we'll see one of those fly?
        
           | walrus01 wrote:
           | I saw photos a few days ago that the base piece of the BN1,
           | which will need to hold the weight of the entire thing and
           | thrust mounts for the engines has been spotted at boca chica.
        
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