back to article Testing times as NASA rattles Mississippi with mighty motor burn

NASA has released a video of last week's test burn of an RS-25 motor, which will ultimately power the core stage of the Space Launch System (SLS). The 535-second blast – equivalent to "the amount of time the engines will fire during an actual launch" – took place last Thursday on the A-1 test stand at the Stennis Space …

  1. Ashton Black

    Obligatory KSP post...

    Needs more struts!

  2. kmac499

    Evolutionary Dead End

    All respect due to the engineers building and testing the safest vehicle they can, but there has got to be a better way than a bloody great one-shot firework.

    You get the distinct feeling that the US Politicians finally woke up to their lack of a launch vehicle, and just told NASA to solve the problem as quick as they could.

    1. Electron Shepherd
      1. Simon Harris

        Re: Space Elevator?

        My, that's a tall bouncy castle!

      2. John Brown (no body) Silver badge
        Mushroom

        Re: Space Elevator?

        Tall towers never end well

        What's that? I can't understand you. Stop babbling!

    2. Anonymous Coward
      Anonymous Coward

      Re: Evolutionary Dead End

      At the rate space junk is piling up it'll all be academic in a few decades since nothing in orbit will be safe for more than a few hours.

    3. ilmari

      Re: Evolutionary Dead End

      Well, instead of riding a tube undergoing a slow explosion, they also tested throwing bombs out the back of a spaceship and surfing the shockwaves from each bomb.

      The tests were performed with TNT, but the final plan called for nuclear bombs. It was calculated that you would only need a few ten thousand nukes to get to Alpha Centauri. For some reason they never received permission to procure and detonate even a dozen nukes, and the project was shut down.

      1. Tom_

        Re: Evolutionary Dead End

        And what was the project called?

        Orion.

      2. asdf

        Re: Evolutionary Dead End

        >For some reason they never received permission to procure and detonate even a dozen nukes, and the project was shut down.

        Funny how quickly all the "peaceful" uses of nuclear weapons disappeared after Strontium 90 started showing up in non trivial amounts in the milk worldwide. Even if you only do it in interstellar space you have to get them up there and make and store them until then all of which are at least mildly frowned upon.

    4. Orv Silver badge

      Re: Evolutionary Dead End

      We've tried one-shot systems, and we've tried a reusable system. The reusable one turned out to be far, far more expensive per launch.

    5. Camilla Smythe

      Re: Evolutionary Dead End

      At a personal level I blame God. After all he could have made things much easier but OH NO..

      <rant>

      -

      -

      -

      </rant>

      Fucking Idiot.

      1. Captain DaFt

        Re: Evolutionary Dead End

        Now, now, you have to admire the sense of humor of a $DEITY that arranged the laws of an entire universe just so the slower traffic is always ahead of you, and the faster traffic behind you, whenever you venture out on the road.

        Sheer genius!

        1. asdf

          Re: Evolutionary Dead End

          >so the slower traffic is always ahead of you, and the faster traffic behind you, whenever you venture out on the road.

          Or has George Carlin pointed out people tend to think everyone driving slower than them is an asshole and everyone driving faster is a maniac.

  3. phil dude
    Thumb Up

    new technology...

    It remains to be seen if humanity can devise a more incremental method of launch, than sitting on a tube full of explosives...!

    The whacky ideas of 50 years ago are seeming less extreme with the discovery of new materials. Perhaps more importantly, the computer technology that can *control* many processes with exquisite precision, for any number of incremental steps.

    Here's hoping that funky "EM drive" gets either thoroughly explained or a new chapter is added to the *slim* book titled "No more research is needed, we're done".

    P.

    1. Kharkov
      Pirate

      Re: new technology...

      New technology that gets you away from that rather inefficient stuck-at-the-top-of-a-tube approach?

      Check out... Skylon

      15 tonnes of payload to ISS orbital height for only around 10 million dollars per flight with a 10-day turnaround between FULLY reusable flights, aboard a single-stage space plane that is due to enter service in 6-7 years...

      A revolution in the economics of space flight...

    2. Paul Crawford Silver badge

      Re: new technology...

      Sorry to have to point it out but a bloody great firework is the only system we have that actually works. Most of the likely (and some amazingly unlikely and down right stupid) fuels have been trialled and the ones remaining (typically kerosene & LOX or LH2 & LOX) are the ones that combine enough specific impulse and scale to get off the ground, while not poisoning us or dissolving the engine.

      If, and it is still a big 'if', we see EM drives working it will be a very low force, otherwise we would have seen it before in experiments as a non-trivial effect. So at best an EM drive will be good once you are leaving the Earth's atmosphere and can get low accelerations for months/years based on solar or nuclear generated electrical power.

      Edited to add: Yes, the Skylon project is really interesting as you could save a lot of the LOX weight by burning atmospheric O2 up to a decent altitude.

      1. Paul Crawford Silver badge

        Re: new technology...

        I don't know of any supportive masterminds with volcanic lairs, but one idea that would also help a bit is a massive mountain-side rail-gun style to allow a proportion of the launch momentum to be delivered from ground-based power. Basically you get your main engine & propellent up to say Mach 1 before it even has to burn.

        It all comes down to getting more thrust from your fuel. Unlikely, except for a reactor heating the propellent and getting THAT cleared for use is not going to be trivial, and we won't even touch on Project Orion.

        Otherwise getting less launch weight and not having to carry the oxidiser (as in Skylon) or by having some ground based propulsion to get you started and a little of the way out of our gravity well.

        1. John Robson Silver badge

          Re: new technology...

          Air is a bit of an issue - maybe doing it on the side of kilimanjaro (fairly tall, and near the equator) might be useful

          1. Tom 7

            Re: new technology...

            Re using guns. Its reasonably economically viable to use a supergun to launch supplies into space, if as pointed out you do it up the side of a huge mountain (or mountain range) near the equator. The Andes is probably OK - the odd earthquake might cause the odd problem but the barrel could be relatively cheap and easy to repair if you dont go for silly pressures and accelerations. You could easily get the bits of a much larger rocket up there and then put them together. Fuel would be relatively easy.

          2. Martin Budden Silver badge

            Re: new technology...

            Air is a bit of an issue - maybe doing it on the side of kilimanjaro (fairly tall, and near the equator) might be useful

            Having walked up Kilimanjaro I can confirm there is significantly less air at the top than at the bottom. Worst headache of my life.

        2. Anonymous Coward
          Anonymous Coward

          Re: new technology...

          People may be a bit too squishy for the acceleration of a railgun..

          1. Paul Crawford Silver badge

            Re: new technology...

            "People may be a bit too squishy for the acceleration of a railgun"

            It depends on what acceleration you are looking for.

            I hope some commentards will check, but I figure that if you had a 2km rail gun on some suitable mountain and were running at 3g sustained acceleration your meat-sacks would survive fine and you would be doing about Mach 1 at the exit point where (hopefully!) the chemical rockets take over 11 seconds or so in to the whole process.

            Also I was thinking of a mag-lav rail and electrically powered linear motor, not a "supergun" and explosive charge.

            1. Simon Harris
              Flame

              Re: new technology...

              " I was thinking of a mag-lav rail"

              Even my toiletry explosions aren't that powerful!

            2. Ken Hagan Gold badge

              Re: new technology...

              True, (or close enough: v = root(2*20*2000) = root(80000) so maybe you need nearer 3km or 3g) but Mach 1 is about 4% of the momentum you need and consequently about 0.16% of the kinetic energy.

              Exercises for the reader: Is it true that if Earth was a bit larger, it would be flat-out impossible for any self-contained chemical rocket to get to low orbit? If so, is that another term for the Drake equation that is usually left out?

              1. Martin Budden Silver badge

                Re: new technology...

                Exercises for the reader: Is it true that if Earth was a bit larger, it would be flat-out impossible for any self-contained chemical rocket to get to low orbit? If so, is that another term for the Drake equation that is usually left out?

                AFAIK the Drake equation is about whether intelligent life exists *on* other planets, not whether they are able to get *off* said planets.

                1. Dave 126 Silver badge

                  Re: new technology...

                  >AFAIK the Drake equation is about whether intelligent life exists *on* other planets, not whether they are able to get *off* said planets.

                  The Drake equation contains this factor:

                  fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

                  If a civilisation that cannot reach orbit, the absence of communication satellites might affect the nature of ERM that they emit.

                  1. mosw

                    Re: new technology...

                    "If a civilisation that cannot reach orbit, the absence of communication satellites might affect the nature of ERM that they emit."

                    Without satellites they could end up relying on higher power ground based radio and therefore be easier to detect.

            3. This post has been deleted by its author

            4. Turtle

              @Paul Crawford Re: new technology...

              "I hope some commentards will check, but I figure that if you had a 2km rail gun on some suitable mountain and were running at 3g sustained acceleration your meat-sacks would survive fine and you would be doing about Mach 1 at the exit point where (hopefully!) the chemical rockets take over 11 seconds or so in to the whole process."

              I don't know if this is either feasible or useful but one could launch a vehicle via this method without a crew, and then send the crew up separately in a roman-candle type rocket or whatever other mode of conveyance won't necessarily kill them. Doing so would allow the rail-gun launched vehicle to be optimized for the strengths and survivability of the hardware as opposed to the weaknesses and survivability of the flesh and blood crew, who would rendezvous with their vehicle in space. This might enable the launch of larger vehicles and cargoes although economies of scale (budgetary and/or engineering) might or might apply.

              Of course there would be a need to engineer the rail-launched vehicle for the launch itself as opposed to being engineered for space-travel proper - two profoundly different sets of engineering requirements. But as a cargo carrier to get materials into space to build a large space-faring ship, it might be useful.

              1. Martin Budden Silver badge

                Re: @Paul Crawford new technology...

                I don't know if this is either feasible or useful but one could launch a vehicle via this method without a crew, and then send the crew up separately in a roman-candle type rocket or whatever other mode of conveyance won't necessarily kill them... ...Of course there would be a need to engineer the rail-launched vehicle for the launch itself as opposed to being engineered for space-travel proper - two profoundly different sets of engineering requirements. But as a cargo carrier to get materials into space to build a large space-faring ship, it might be useful.

                A rail gun would certainly be a way to get a large tank full of fuel into orbit. It can then be used fuel-up any spaceship you've managed to get up there by other means.

                1. Orv Silver badge

                  Re: @Paul Crawford new technology...

                  I think the big problem with a rail gun is you have to impart all the momentum right at the start. It turns out you really *don't* want to accelerate too fast in the lower atmosphere if you can avoid it, because you end up losing a lot of energy to air friction.

        3. Robert Helpmann??
          Childcatcher

          Re: new technology...

          ...one idea that would also help a bit is a massive mountain-side rail-gun style to allow a proportion of the launch momentum to be delivered from ground-based power.

          There are a number of possibilities that have been explored in this regard such as firing a laser at the bottom of the craft to superheat the air beneath it. That's pretty nifty, but my favorite is the space gun which would be capable of literally firing objects into space (much as the name implies). The US Navy has a railgun project that is coming close to being able to do this with small objects, but these are meant to come back down. Still, if the research put into that could be further developed to launch things with a reasonable amount of acceleration (without turning people into paste), we might have a winner.

          For purposes of comparison, escape velocity is about 11.2 kps (81 bnps) and the USN railgun will fire projectiles at about 2.5-3.5 kps (18-25 bnps) while the fastest bullet train taps out at around .17 kps (1.2 bnps).

      2. GrumpenKraut
        Mushroom

        Re: new technology...

        > ... the only system we have that actually works.

        Apart from that it has to be appreciated that an enormous amount of money and engineering is spent on an event where lots of scientists are watching, for more than 500 seconds and with straight faces, to the world's largest fire fart simulation.

      3. John Smith 19 Gold badge

        Re: new technology...

        "Yes, the Skylon project is really interesting as you do save a lot of the LOX weight by burning atmospheric O2 up to a decent altitude."

        FTFY

    3. This post has been deleted by its author

  4. Pete4000uk

    Brave people

    I don't know what would be more scary - being in space or sitting atop such a contraption beforehand.

    1. TitterYeNot

      Re: Brave people

      "I don't know what would be more scary - being in space or sitting atop such a contraption beforehand."

      To quote John Glenn (veteran Space Shuttle & Mercury programme astronaut), I would guess it's the latter...

      I guess the question I'm asked the most often is: "When you were sitting in that capsule listening to the count-down, how did you feel?" Well, the answer to that one is easy. I felt exactly how you would feel if you were getting ready to launch and knew you were sitting on top of two million parts -- all built by the lowest bidder on a government contract.

  5. Anonymous Coward
    Anonymous Coward

    I can't help feeling that the whole launch a completed satellite into space thing is getting a bit silly and perhaps it's time we started to seriously explore at least partial in space construction. The current method relies on everything going perfectly every time. Even a slight failure of the launch system results in total failure and the loss of 70 tons of very expensive equipment.

    The alternative would be multiple much small launches, lets say 100 1 ton launches. Chances are one would fail but over all I think it could still work out cheaper. One obvious potential advantaged would be the possibility of using exotic launch systems (e.g. mass drivers) for parts that are robust and able to handle the g-forces. Additionally once we have in space construction sorted out we can start building big things in space, imagine being able to build the thirty meter telescope in orbit!

    1. Charlie Clark Silver badge

      Actually, I think larger launchers are more cost-effective. For every launch you are paying to launch both vehicle and payload so the economics of scale apply.

      This doesn't preclude assembling stuff in space but, as the ISS is testament to, this is far from easy: gravity and radiation shields in the form of an atmosphere have their advantages. I suspect this is why the moon is so attractive as a half-way house: possible to build large facilities reasonably easy and low enough gravity to make really large launches possible.

      1. Orv Silver badge

        I don't think the moon is that useful as a staging ground, unfortunately. It has most of the disadvantages of building in orbit -- no radiation shielding, no atmosphere -- and 1/6 g is still quite a deep gravity well to get something out of. It negates one of the biggest potential benefits of building in orbit, which is you can build a lot lighter if your vehicle never has to support itself against gravity.

        1. oldcoder

          There is a LOT of radiation shielding available.

          At a minimum 50% right of the top (a little better than LEO). And if you build in a rill up to 60%.

    2. Alan Brown Silver badge

      Losing a payload in a launch incident isn't that much cost.

      Hundreds of prototypes are built to make sure everything will work and the incremental cost of building a backup is tiny so there's always a backup.

      The major expense is R&D and all that cost is counted as part of the launch price.

      It's a bit easier with cookie-cutter systems such as geostationary comms birds and that's reflected in their vastly lower per-launch cost, but even then no two are the same.

      This is 21st century craftsmanship producing one-offs at least as wonderful as one of Fabergé's eggs.

  6. Lars Silver badge

    I wonder how much lake water was needed to cut the sound and cool it down.

    1. Stevie

      4 Lars

      "I wonder how much lake water was needed to cut the sound and cool it down."

      None to cool the engine. Rocket engines like this are of a regenerative design. The parts that need cooling are cooled by passing unburned fuel through them. Same as the fuel pump for the TR6.

      1. Tom 7

        Re: 4 Lars

        The lake was to cool the deflector - there was a shit load of water used to stop the motor becoming the biggest oxy cutter going.

        1. Orv Silver badge

          Re: 4 Lars

          On shuttle launches they also used a water spray system to help absorb some of the noise of the engines. On the first shuttle launch they didn't have the system, and the reflected noise was so intense it damaged the shuttle's tail.

      2. Lars Silver badge

        Re: 4 Lars

        @Stevie, Yes I know, it's not about the engine. Water is used with every launch. It's not only smoke in the video but a hell of a lot of steam from the water. To explain why water cuts the sound and the vibration will require the Wikipedia, apart from that, water is needed to save the launch pad. I just wonder how much water, like gallons per second.

        1. werdsmith Silver badge

          Re: 4 Lars

          For the Pad 39 Space Shuttle launches the peak flow is apparently 900,000 US gallons per minute for the Sound Suppression Water System.

          http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-lc39.html#sts-lc39-ssws

          But it must vary as they only store 300,000 US gallons for the launch. Must have been much more for this static test where the motor doesn't shoot off.

          I was wondering what that steam plume would do to the already humidity laden Mississippi air.

          I was also wondering what all those people were staring at for 9 minutes. Once you've seen 10 seconds of that video, you've seen it all.

        2. John Robson Silver badge

          Re: 4 Lars

          @Lars - Not only smoke

          It's an H2/O2 engine - there is no smoke, it's all water...

  7. hplasm
    Coat

    Impressive engine-

    But who were the daredevils in the gazebo right next to the test stand?

    Extreme Marshmallow Toasters?

    Deaf People?

    Both? ( if a, then probably now c)

  8. Little Mouse

    But which way was it pointing?

    That mighty thruster was securely bolted to Earth at the time of firing. Presumably it changed our orbit a little bit...

    Hopefully the burn was cut off before Earth was sent careering off into the depths of space, Moonbase Alpha style.

    1. Anonymous Coward
      Anonymous Coward

      Re: But which way was it pointing?

      That mighty thruster was securely bolted to Earth at the time of firing. Presumably it changed our orbit a little bit...

      Given that the outlet pointed sideways isn't it more likely it affected precession and/or rotation?

      :)

    2. oldcoder

      Re: But which way was it pointing?

      No change in orbit. The entire results of the burn remained in the atmosphere - just heated up a bit.

      And this was a little engine. Not yet as large as a Saturn V, which was known to crack windows in Slidell (the closest town).

  9. Anonymous Coward
    Anonymous Coward

    "The combined thrust will be sufficient to lift 70 metric tonnes"

    Incorrect ( it lifts much much more at liftoff )

    Or meaningless without the orbit to which it lifts that mass.

    This bit of rocket science is really not that tricky.

    1. Tom 7

      Re: "The combined thrust will be sufficient to lift 70 metric tonnes"

      You'd need 45 of them to get a Saturn 5 off the ground!

    2. werdsmith Silver badge

      Re: "The combined thrust will be sufficient to lift 70 metric tonnes"

      70 tonnes is the rocket payload to low earth orbit.

      I expect that means that they are planning a vehicle and fuel load to achieve that.

      The Saturn V weighed nearly 3000 tonnes on the pad, and its payload to LEO was 120 tonnes.

      Still unsurpassed, nothing getting anywhere near it.

      This SLS development is planned to go to 130 tonnes, this first block plan is to 70, block 1b to 100 and then block 2 eventually to 130 tonnes.

  10. Charlie Clark Silver badge
    Megaphone

    In the meantime…

    The ESA last week signed the contracts for the Ariane62 and Ariane64 next generation launchers intended to be competitive with SpaceX and China. Coverage on El Reg? No, because it offer much of an opportunity to bash the EU.

    1. phuzz Silver badge
      Facepalm

      Re: In the meantime…

      Contracts being signed you say? Wow, I hope there's a webcast of that! Far more interesting than GIANT ROCKET ENGINES BELCHING FIRE!

      /sarcasm

  11. Anonymous Coward
    Anonymous Coward

    Actually been there ...

    back in 1990. Driving along the I10, from Louisiana to Florida. We saw a "NASA Rocket Test facility" sign, and decided to check it out. This was December, so hardly peak tourist. We had a guided tour, with the observation that if we had been a day earlier, the facility would have been closed to visitors, due to a "special" test (go figure).

    Can highly recommend it. These guys were geek major.

    Saw the test platform from about 3 miles away :)

    On the same trip, we visited Blackwater park in Mississippi - we were the only visitors that week.

    1. Ugotta B. Kiddingme

      Re: Actually been there ...

      I drive by there frequently as I have family in the area. The visitor center (where you catch the shuttle bus to Stennis) is right off the I-10. First eastbound (or last westbound) exit in Mississippi. They recently opened the new Infinity Science Center adjacent to the visitor center. Haven't been in the Infinity addition yet but looks pretty awesome from what I can see passing by and from their website.

    2. Peter Simpson 1
      Mushroom

      Re: Actually been there ...

      REAL Rocket Scientists!

      Impressive. Although, we've done this once before with Saturn V.

  12. GregC

    I much prefer the other approach to that kind of diagram...

  13. Tom 7

    I do miss vinyl.

    NT

  14. Gene Cash Silver badge

    It's not a launch vehicle

    It's a jobs program. As all new NASA launchers, especially manned ones, it'll get 90% to flight and be canceled. Remember Venturestar (aka X-33)? Remember the Constellation program? Remember Ares I (which actually got one test launch) and Ares V? All canceled after tons of money was spent.

    I give it about 15% chance of a flight, and no chance of a second flight.

    Congress is trying hard to cancel the commercial crew capsules as well, but they've got Elon Musk to deal with, so it won't be the usual stroke of a pen.

  15. Andy The Hat Silver badge

    alternatives?

    Skylon as a flying craft is still vapour-rub.

    NASA using the most reliable rocket engine - modified and power boosted - so potentially as reliable as sticking a turbo on a Fergie tractor engine then.

    SpaceX ... getting close but still not there.

    Diamond elevators? Not in my lifetime.

    For reasonable economics and safety my money is still on the Iron Chicken from the Clangers ... if she just let down a rope we could climb up ... it is a documentary isn't it?

    1. MD Rackham

      Re: alternatives?

      Steam launchers.

      Spray water vapor into an expansion chamber at the back of the rocket, pulse a laser up it and the expansion of the steam provides thrust.

      Power storage on the ground to run the laser is a challenge, but recent progress in military lasers (US Navy) is quite promising.

      Oh yeah, you also have to have a really good aiming system, although you need that for zapping incoming hypersonic missiles too.

      1. Orv Silver badge

        Re: alternatives?

        Steam is an intriguing thought, but I think you'll find it gives you less thrust for a given amount of liquid weight than the alternatives. You get a two-fer with hydrogen or kerosene; chemical energy being released *and* expanding a liquid into a gas.

      2. Guido Brunetti

        Re: Steam launchers

        Even if this would work (big if), it just takes the rocket straight up. But that is just the easy part of a rocket launch. Now you have to accelerate to 17.000 mph *sideways* to get it into orbit.

    2. Anonymous Coward
      Anonymous Coward

      Re: alternatives?

      I'm still trying to wrap my mind around how they developed reliability figures here. Oh, project reliability will be higher.

    3. Captain DaFt

      Re: alternatives?

      Or just get Gumby's dad and a ladder truck: https://youtu.be/wt87rvCPViQ

  16. Mr_Pitiful

    OK so how fast

    does it go from 0 - 60Mph?

    1. Anonymous Coward
      Anonymous Coward

      Re: OK so how fast

      That depends how long does it take for you to shit your pants?

      I am sure a little algebra in between should be able to complete the equation.

    2. Orv Silver badge

      Re: OK so how fast

      That's a bit like asking how fast a car engine can go 0-60. It depends almost entirely on how heavy the thing you bolt it to is.

      1. Ken Hagan Gold badge

        Re: OK so how fast

        Wikipedia has the numbers for a Saturn V ( https://en.wikipedia.org/wiki/Saturn_V ). There's a rather nice graph of g-force against time and (a real gem here) the text notes that they actually had to *turn off* one of the 1st stage engines in-flight to avoid squishing the payload. :)

        Apollo was abso-fucking-lutely awesome.

    3. oldcoder

      Re: OK so how fast

      How about 0 - 17,000 Mph in 11 minutes.

    4. Ken Hagan Gold badge

      Re: OK so how fast

      Oh, and the 0-60 time for the Saturn V is apparently 4.5 seconds.

      And that's straight upwards. It would be about half that on the level. No brakes, though. Enjoy.

      1. John Crisp

        Re: OK so how fast

        Think they reckoned it was doing 100mph by the time it cleared the tower.

        No matter. Numbers will never do a Saturn V justice.

        It's like trying to describe say a Ferrari.

        I remember well watching launches as a kid. Mind numbing. Awe inspiring. I was 'there' when they stepped on the moon. I felt I held hands with the planet during Apollo 13. Amazing times.

        I think it was Michael Collins who when asked what it was like to ride one said something like

        "Imagine being strapped to the top of the biggest firework man ever built, they lit the blue touch paper, and then watched from the safety of their bunkers...."

        Damn. Come on. Do it again....

        1. Ken Hagan Gold badge

          Re: OK so how fast

          "Imagine being strapped to the top of the biggest firework man ever built, they lit the blue touch paper, and then watched from the safety of their bunkers...."

          Ah, bunkers. That's yet another thing they learned the hard way. The Apollo 4 launch was so loud it damaged the press building about a mile(?) away. Later Apollos had some sort of sound suppressors.

          https://www.youtube.com/watch?v=1uoVfZpx5dY

  17. Unicornpiss
    Alert

    Powerful?

    Bring back the Saturn rockets!

    1. Mark 85

      Re: Powerful?

      Wishful thinking indeed. As I recall, the plans had to be destroyed as some Air Force money was involved. OTOH, they do have one of the original motors recovered recently. The ones in the museums are all basically dummies and missing some key parts.

  18. Sorry that handle is already taken. Silver badge

    "The combined thrust will be sufficient to lift 70 metric tonnes"

    Tonne is already metric!

    If you're a seppo it can be a "metric ton", but even that's awful.

  19. John Smith 19 Gold badge
    IT Angle

    This thing has the mother of EMU's on it.

    The last upgrade (from a proprietary ISA processor with plated wire memory) was to a pair of M68000, however it turned out that to keep them in close enough synchronization they had to be on the same chip.

    A project killer for most projects but not NASA.

    Who simply asked Motorola to run off a special batch of twin 68k's.

    The new design presumably won't need that design "feature" this time round.

    While the running engine is quite well behaved something like 13 power heads (the parts around the drive turbines) were destroyed working out the start sequence. You might say the turbines are "bump started" by a series of "burps" as the LH2 flash boils when first flowing into t pump impellers (IOW the pump impellers start the turbines, not the other way round, before ignition).

    The process is delicate. One head got blown up because the sensor reading the valve open angle was off by one degree.

    In theory since the SLS engines (RS25D) will be short life they can be made lighter and simpler by simplifying all the bearing packages and deleting the GHE purge gas tanks, each about 300lb

    Wheather this will be done is another matte.

  20. DriveBy

    Presumably this is just another example of NASA demonstrating its concern for the threat of global warming/climate change?

    1. Mark 85

      It's a hydrogen/oxygen engine. No hydrocarbons. No CO2. Just water and heat out. I doubt there's enough heat to change the climate.

    2. Sorry that handle is already taken. Silver badge

      And that cloud coming out of the test stand is just steam from the water dumped in by the deluge system.

  21. Ralph B

    Not A Rocket

    That's not a rocket. That's Hotblack Desiato testing a smoke machine for the next Disaster Area concert.

  22. Dr Patrick J R Harkin

    "See http://www.telegraph.co.uk/news/science/science-news/11805987/Inflatable-space-elevator-invented-by-scientists.htm"

    I knew they were remaking Thunderbirds with CGI actors and real sets but I didn't realise the sets were going to be full-scale. Let me guess - the tower springs a leak and the blast of expelled air blows the World President's jet off course into the jungle while the tower looks like it'll fall on Lady Penelope who is trapped in her car and Scott has to prioritise personal feelings against civic duty?

  23. Zmodem

    think i would be as bored going into space as i was watching the video

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