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Battle of the Heavy Lift Rockets 211

Posted by Soulskill
from the go-big-or-stay-home dept.
schwit1 writes: Check out this detailed and informative look at the unspoken competiton between NASA's SLS rocket and SpaceX's planned heavy lift rocket. It's being designed to be even more powerful than the Falcon Heavy. Key quote: "It is clear SpaceX envisions a rocket far more powerful than even the fully evolved Block 2 SLS – a NASA rocket that isn't set to be launched until the 2030s." The SpaceX rocket hinges on whether the company can successfully build its new Raptor engine. If they do, they will have their heavy lift rocket in the air and functioning far sooner than NASA, and for far less money.
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Battle of the Heavy Lift Rockets

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  • by Z00L00K (682162) on Sunday August 31, 2014 @08:29AM (#47794855) Homepage

    There have been way too little competition in this area the last decades. Considering that the Russian RD-180 engines designed in the 70's&80's are still seen as state of the art it is obviously a stagnant situation.

    • No miracles (Score:5, Informative)

      by nojayuk (567177) on Sunday August 31, 2014 @09:44AM (#47795071)

      There are no miracles in rocket engine design. The RD-180 has pretty much the best performance to be wrung out of a sea-level-to-altitude LOX/RP-1 motor in terms of efficiency. SpaceX is still playing catchup in that area, trading off the lower cost per Merlin motor for a lower Isp from a simpler design.

      As for the Raptor the "new" liquid-methane/oxygen fuel mix it will burn has the potential to produce a higher Isp than the current mainstream LOX/RP-1 mix used in motors like the Merlin, the RD-180 etc. but it comes with downsides -- it means a redesign of the rocket structure to support fully cryogenic tankerage (although not requiring the sorts of extreme temps or processing LH needs), launchpad facilities for fuelling and defuelling rockets will need to be revamped, liquid methane is half the density of RP-1 so the tanks and the rocket structure need to be larger and heavier to contain equivalent amounts of fuel and so on.

      • Re:No miracles (Score:4, Interesting)

        by 0123456 (636235) on Sunday August 31, 2014 @12:25PM (#47795579)

        Efficiency is irrelevant when fuel makes up about 1% of the cost of a launch and bigger tanks are cheap. When you're throwing engines away every time, and they make up a large fraction of the cost of a launch, a low-cost engine that burns 10% more fuel can be a massive win.

        Government rocket engineers have been fixated on efficiency because they rarely have to worry about cost. They can just steal more money from taxpayers.

        • by evilviper (135110)

          Efficiency is irrelevant when fuel makes up about 1% of the cost of a launch and bigger tanks are cheap.

          Until the larger tank and extra weight then means you need an even larger (or more) rocket motor(s) to get off the ground and into orbit.

        • I believe that methane was actually chosen (among other reasons) so that the stage (and the engines) could be more easily reusable: unlike kerosene, it shouldn't create an awful residue all over the fuel system.
    • by evilviper (135110)

      Considering that the Russian RD-180 engines designed in the 70's&80's are still seen as state of the art it is obviously a stagnant situation.

      Just wait until you find out how old screwdriver and pliers designs are...

      The rest of the world does NOT resemble IT. Stability is a good thing. If you've got a 99% efficient rocket engine that's reliable and cheap to produce, you should stick with it as long as you possibly can. The real shame of the US space program is that we stopped making Saturn V's... If

  • by Dan Askme (2895283) on Sunday August 31, 2014 @08:35AM (#47794873)

    Mr. Mueller then later updated his numbers at a follow-on conference to portray 6,900 kN of sea-level thrust, and 8,200 kN of vacuum thrust.

    That took me 20 seconds to find.

    Come on, its Slashdot, at least give us some technical information to back up the story.

  • If anyone can get it done, it will be Elon Musk and SpaceX. They have the vision and agility that NASA lost in the sixties.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      NASA never had agility. Vision sure, but the entire institution was intentionally designed to be scattered and resistant to change. It's difficult to be institutionally agile when you're operations are spread out into as many political jurisdictions as possible.

      • by 0123456 (636235)

        NASA went from the first suborbital manned flight to putting men on the freaking Moon in eight years. They were pretty agile back then.

        Now they're spending longer than that just building a rocket that largely uses existing hardware, and has no funded missions that would require it.

    • by cytg.net (912690)
      Well, when talent begins leaving NASA for SpaceX, then we know its in business...
      • by Fjandr (66656)

        Talent isn't leaving NASA for SpaceX. The talent is never getting to NASA in the first place. A number of high-profile candidates courted by NASA have declined job offers in favor of positions in private space flight companies.

    • They have the vision and agility that NASA lost in the sixties.

      I get smacked down here for suggesting that NASA is no longer the best agency for moving the space program forward. SpaceX soft-landed two boosters in the ocean and are ready for a land trial. They did that in their spare time. It would have taken NASA 10 years and $20 billion dollars to replicate that achievement. NASA also relies on contractors with obscene overhead rates.

      SpaceX is living proof that NASA wastes billions.

  • by trout007 (975317) on Sunday August 31, 2014 @08:42AM (#47794895)

    NASA never wanted to build this rocket. It was forces in them from Congress. Plus NASA doesn't build rockets it overseas other aerospace contractors.

    • by TwoUtes (1075403)
      That is it in a nutshell. NASA programs have always been subject to the whims of politicians. I'd bet that the next administration/congress cancels SLS after the next presidential election, and NASA will again look inept and directionless.
      • Probably not, if the pictures of Pluto returned back by the New Horizons mission are still fresh on people's minds.

    • Re: (Score:3, Informative)

      by tomhath (637240)
      The rocket they really wanted was Constellation, but Obama cancelled that one.
      • by Bo'Bob'O (95398) on Sunday August 31, 2014 @02:32PM (#47796045)

        And in it's place we got the commercial cargo and commercial crew programs, which have been highly successful so far. So much so that NASA is now looking to duplicate the process in other endeavors: http://spaceflightnow.com/news/n1407/27marstelecom/#.VANoxEi0b0c

        Meanwhile the Orion capsule, which was the part of the constellation project that actually put humans on top of those rockets to get them into space, was kept. It's still over budget, under speced and years off from putting anyone in space.

      • Congress had already de-funded it once they realized how much it was really going to cost. He just killed a program that had been declared dead in the water before he took the oath of office.
  • by tekrat (242117) on Sunday August 31, 2014 @09:18AM (#47794993) Homepage Journal

    I mean seriously, look at the SLS, it's almost entirely composed of re-used space shuttle parts. It has the main engines on the bottom of the tank re-purposed from the shuttle. it has solid rocket boosters which already exist from the shuttle -- it entirely looks like it could be cobbled together in a few month's time because it uses almost entirely existing components.

    So what exactly requires so many years to make it al work when it's all basically existing tech from the shuttle? I hate to say this, but this ain't rocket science.

    • by db48x (92557) <db48x@db48x.net> on Sunday August 31, 2014 @09:59AM (#47795103) Homepage

      Unlike in Kerbal Space Program, when you stack rocket components on top of each other you have to reengineer the bottom one to hold up the top one; they say that they're reusing the main tank, but that might be true in a narrow sense if they reuse the H2 tank inside the orange Space Shuttle External Tank. Then you have to engineer the manufacturing processes and factories for producing any new components (and there will be lots of those), plus the modified one (easier, but still plenty to go around), plus you have to engineer the test facilities for all the components, and you have to test the test facilities, and then test the components, and then test-launch the vehicle, etc. Don't forget to document everything, and to design training procedures so that you can hire new people to build these things, and test them, etc, etc. It actually is rocket science.

    • by kellymcdonald78 (2654789) on Sunday August 31, 2014 @11:43AM (#47795431)
      While the "Shuttle Derived" messaging was used to sell the program, it's hardly anything but. The first few flights will use left over RS-25Ds from the shuttle program, but they are far too expensive for new ones to be built and throw away each flight, so the RS-25E and RS-25F engines needed to be developed. The 4 segment SRBs from the shuttle aren't powerful enough for SLS so they've had to develop a 5 segment SRB with a new type of solid fuel with a completely new grain. The casings are also being redesigned to be expendable. While the tank is shuttle derived, it needs a completely redesigned aft section to support the engines, plumbing is completely different, and the a new interstate to support the upper stage and payloads. It would have been cheaper and faster to start from scratch, but that doesn't keep the trough filled.
    • Re: (Score:2, Interesting)

      by petes_PoV (912422)

      So what exactly requires so many years to make it al work

      It takes as long as it does, because that is the amount of time (or money: same principle applies) than is allotted to the project. Finishing sooner makes no sense as you'd just be working yourself out of a job earlier. There is also no pressing need to have such a vehicle. It's not as if there was a killer asteroid heading this way that would spell doom - and worse: upset NASA's carefully crafted timetables.

      In that situation, where there was a deadline to be met (and not a vacuous political one), then ye

    • by PPH (736903)

      Because the primary contractor's business is cobbling stuff together designed and built by others.

    • by 0123456 (636235)

      Remember, this is the organization that needed half a billion dollars to put a dummy upper stage on top of a shuttle SRB and launch it into the ocean. There was a very brief period when NASA did cheap unmanned missions under the 'cheaper, faster, better' slogan, but that was long ago now.

  • by Irate Engineer (2814313) on Sunday August 31, 2014 @09:25AM (#47795017)
    NASA would be very happy to let SpaceX build a heavy lift booster for them. Really.

    The only reason SLS exists is to keep the congresscritters from the former shuttle supply chain districts happy. That's it. NASA is desperately trying to keep funding going, and they ain't interested in pissing that money away on designing big dumb rockets, but politics says that they must to survive. Rockets are rapidly becoming a commercial technology, which is a good thing.

    NASA would be very happy to buy rockets from Elon Musk and/or whoever else can put up competing articles. NASA would much rather be doing and spending its hard-fought budget on things that they do well, pushing the envelope on technologies for hard problems, like getting our asses to Mars, and science missions.
    • NASA would much rather be doing and spending its hard-fought budget on things that they do well, pushing the envelope on technologies for hard problems, like getting our asses to Mars,/quote Elon Musk may very well beat NASA at that, too

    • I've come to the conclusion that this may be the unspoken official plan. Congress is driving NASA to do what they're doing; but, the Administration is sort of sitting back quietly saying very little. Note how you don't hear much from the Obama administration about SLS; but, they keep pushing Commercial Crew. I think it is possible they're just waiting for SpaceX (or one of the other commercial contractors) to fill the void and provide commercial launch capability. NASA has leased launch facilities to
  • 3 companies vie to build space shuttle successor

    http://www.cbsnews.com/news/ne... [cbsnews.com]

  • Nasaspaceflight.com (Score:3, Informative)

    by jpfulton (2075948) on Sunday August 31, 2014 @11:38AM (#47795417)
    For those of you who visited the link, Nasaspaceflight.com has a very well-informed stable of posters, many of whom are professionals in the space industry, and there is the L2 section where you will find much that is not available anywhere else.

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