49 thoughts on “Giant Rockets”

  1. SpaceX continues to roll on like Juggernaut’s Carriage.

    To the extent that SpaceX can be said to have had any remaining credibility problems with anyone who actually counts, the events of Feb. 6 have put paid to virtually all of them.

    The hard-core anti-SpaceX snipers have been deprived of their biggest talking point. Falcon Heavy’s success isn’t going to shut them up, of course. Nothing short of an extinction-level asteroid strike will do that. But it will serve to move them much closer, in the public mind, to being peers of those cartoon cliche cranks wearing sandwich boards proclaiming “The End is Near.”

    The freshly re-dug post holes for the well-traveled Anti-SpaceX goalposts are now out there in “Well, what about BFR? That’s going to take forever/never fly (choose one).” territory.

    There was a time when the serial destruction of anti-SpaceX predictions used to induce a bit of schadenfreude as they were ground mercilessly to flinders. But it’s happened so often there is no remaining sport about the process, just a grim inevitability as the list of SpaceX firsts and superlatives inexorably lengthens.

    1. Nothing short of an extinction-level asteroid strike will do that.

      When I saw the two boosters come back to KSC and land, that’s what I was thinking. A NASA extinction-level asteroid struck in the image of 2 reusable rockets landing on their respective pads ready for more fuel and the next launch. Boom!

    2. On leftist Twitter I’vr seen trolling against both Tesla and SpaceX saying that instead of spending money on these projects the money should instead be spent on the homeless.

      The first time I saw this was in response to plans to put a restaurant at a Tesla supercharger station in the Las Angeles area.

      *rolls eyes*

      1. SpaceX’s success seems almost like an Ayn Rand plot come to life. I’m not surprised statists of any flavor don’t like it.

        1. SpaceX’s success seems almost like an Ayn Rand plot come to life. I’m not surprised statists of any flavor don’t like it.

          Musk has not been shy about his support for Obama in particular or Democrats in general. Is it sincere or self serving?

          1. Musk donated five grand to Obama’s two campaigns. Over the years, he has contributed more money to Republicans than Democrats. This meme that Elon is some sort of Obama crony seems evergreen on the more dimwitted right wing websites, but there is no factual basis for it. Musk seems to be largely apolitical. To people on both the Left and the Right to whom politics is life, this is apparently incomprehensible.

      1. Yes it does. Especially in Congress. But a combination of NewSpace advances and, sad to say, the increasing attention paid by The Grim Reaper to the Baby Boomers will eventually lay it in its grave.

        1. Baby Boomers aren’t stupid though. They know what it means when FH can fly as many missions as needed in a year for a fraction of the cost of a single SLS launch. They just need to be educated about the current state of affairs, but space stuff doesn’t break out of its media niche very often.

          1. Unfortunately, a lot of them are stupid. I take no pleasure in saying this as I’m a Boomer myself. It is, nonetheless, true.

  2. BFR just seems right sized to me. I expect it will be the smallest of all future SpaceX vehicles.

    Although it may carry 100 I expect it will routinely carry less than 3 dozen. For passenger service between planets they will definitely end up on bigger ships. The BFR may end up mostly being a shuttle to orbit. Going between orbits doesn’t require such tech.

    1. “For passenger service between planets they will definitely end up on bigger ships. The BFR may end up mostly being a shuttle to orbit. Going between orbits doesn’t require such tech.”

      Once larger and lighter cruising ships for interplanetary travel are built at places like EML-1, then I would expect that BFR/BFS will be shuttles from Earth, the Moon, Mercury and Mars, to and from orbit. The Outer Planet Moons may use them, unless something more specialized has come along by then.

  3. I think I’ve asked about this before, but I still don’t have it. Why would Musk say that he would retire Falcon 9 when he has BFR? What is different about BFR that would make it cheaper to launch a 2000 pound satellite on BFR to LEO than on a much smaller Falcon 9?

      1. Could you explain that? What is not reusable about Falcon 9 – do you mean the fairing, or the second stage? Why can’t those be made reusable, and how does BFR solve that?
        Thanks – Just trying to get this straight.

          1. “reusable without refurbishment” That would be great; that’s (part of) what made Shuttle so expensive to reuse. Do the rest of us have any idea what is involved in refurbishing Falcon 9 and why BFR wouldn’t need that?

        1. Fairing and upper stage. And though it’s possible that they will attempt to recover an upper stage this year (as Gwynne said in September), they’ve probably abandoned any hope of doing it routinely and if they do, it will be an experiment for data gathering, not a demonstration.

          BFR (really, BFS, the BFR upper stage which he says they’ll start testing next year with hops that could eventually become orbital) solves it by being much bigger, having more margin for propulsive entry, and easier to manage entry in general.

          1. I think the other answer to MikeR’s original question is: BFR’s larger payload – double Falcon Heavy, I believe, and about five or six times that of Falcon 9. So, more satellites per launch, with resulting economies of scale. You would probably not use a BFR to launch just one spacecraft, unless it was going quite some ways.

    1. F9 and BFR might fly aside each other for some time. BFR/BFS gets their own manufacturing facilities and they can build out a lot of F9 first and second stages before BFR/BFS hits the market.

      1. I will not be surprised if they make a reusable upper stage for the FH, just to test upper stage reusability technology before BFR.

        1. I hope you are right.

          It would be funny if that 2nd stage could be used on a F9 and while reducing its payload somewhat, put the F9 in the smallsat market.

    2. “What is different about BFR that would make it cheaper to launch a 2000 pound satellite on BFR to LEO than on a much smaller Falcon 9?”

      If you have the BFR, one BFR can serve the entire existing launch market if it can launch weekly much less daily. It’s more that once you have BFR, its marginal cost is much less than the total cost of maintaining the Falcon line. That said, they’ll likely keep Falcon around as long as people prefer it or prefer diversity of options.

  4. I think that one thing that must be kept in mind is that Musk will not have a monopoly on cheap launches. He has shown the way. But Space-x is not the only organization that can achieve. In time there will be others with maybe even better ideas.

    Entrepreneurs are like that.

    1. More competition in the launch market is great but it should be really entertaining to see what their customers pay them to put into space. There are a lot more people/business capable of building something that can work in space than are capable of building their own reusable launcher company.

  5. Anyone know how long SpaceX has been testing the three engine burn used for the FH landings? The first I read about it was for the previous F9 flight that ended up floating in the ocean but I assume that wasn’t the first time.

    1. It looked to me like the nearer one of the FH boosters started with a three-engine landing burn then switched down to one for the actual landing, while the other did a single-engine burn all the way down. The nearer one lit later, but they both landed at the same time.

      1. It was a clever camera angle that made it appear as if they landed at the same time. I wonder if that was intentional. Other camera angles show them coming down at different rates. One actually got down a lot faster and seemed to almost hover for a bit, waiting for the other one. Still very impressive no matter what camera angle.

        Will have to go rewatch and look for what you mentioned.

  6. Several items….
    1)I think the Retro burn is 3 engine (and always has been)
    I believe the landing burn was 1 engine for this launch.

    2)BFR…. it costs say 700K to charter a 747 from LA to Australia…
    The smallest plane one might be be able to make the trip in (with multiple hops) is >$3M.

    So its cheaper to charter a 747 (BFR) for the flight than to buy a smaller plane (F9) and throw it away….

    If BFR gets to gas and go reuse it will be cheaper to launch than ANY expendable of any size. The Tiny rocket lab launcher will cost more to launch than BFR.

    There are square /cube law issues here that make fully reusable easier at a larger size….

    1. Landing burn was 1-3-1 for all three stages. It worked for the side boosters, but didn’t (this time) for the center core. You can see the 1-3 portion for one of the side boosters in SpaceX’s webcast. This will take you to T+07:14, when ground-to-air video of that booster starts, with the landing burn starting 34 seconds later. The outer two engines light up about three seconds after the middle one, and then the business end of the booster is quickly lost from the field of view; but if you pause it and step frame by frame ( , and . keys), you can clearly see the three engines burning.

    2. 1)I think the Retro burn is 3 engine (and always has been)
      I believe the landing burn was 1 engine for this launch.

      Thanks. IIRC, articles about the floating F9 said they were testing three engine burns, so maybe it was just for a different stage in flight than they are normally used in.

      When Musk said two engines on the center core didn’t ignite, was this during the retro burn or for the landing burn?

      1. My impression was that the Govsat booster (the floater) was testing a three-engine-all-the-way-to-the-deck landing burn that starts later, uses less total propellant mass and runs a shorter time at higher G’s than the 1-3-1 burns.

        The outboard two engines on the FH center core re-lit for the entry burn, but failed to relight for the landing burn. It was said that, for some reason, there was insufficent hypergolic TEA-TEB to get them going.

  7. Heavy has 27 engines and BF has 32, right? But the engines in Heavy are sort of spread out in a line, while the engines in BF will be all in a circle. The engines in Heavy get to radiate heat out to the side, perpendicular to the side cores, but the engines in the middle of BF will be surrounded on all sides by flaming infernos. What if the middle BF engines always get crispy and melted and frequently explode?

    1. The engines will mainly be getting heat from the hot dense gas inside them, not radiation from the engines and plumes around them. In both cases, the heat gets carried away by flowing propellant while the engines are firing. Radiant heat can also be rejected by making the engine surfaces reflective.

    2. 31, actually.

      If your posited scenario for interior engines in clusters were actually a thing, the Falcon 9 would already “frequently explode,” but it doesn’t. Ditto the Saturn V back in the day.

    3. It is 27 Merlin engines vs 31 Raptor engines, with the Raptors to have at least double the thrust of a Merlin. So, at least 62 times the thrust on BFR vs FH. If all goes as planned, of course, and I am not going to put down bets against Musk in the near future.

        1. He does. Block 5 Merlin 1-D’s will yield 210,000 lbf each at sea level. For FH, with 27 Merlins, that’s just short of 5.7 million lbf at liftoff. Raptors will produce about 380,000 lbf each – not quite twice a Merlin. But, there will be 31 of them on the BFR booster stage. That’s about 11.8 million lbf at liftoff. So, in terms of liftoff thrust, BFR = 2.08 FH. A fully reusable BFR will have a better than 3-fold advantage in throw weight to LEO over a maximally reusable FH because its methalox propellant mix yields better Isp than FH’s kerolox.

  8. SpaceX’s plan to start with BFS (the upper stage/vehicle) first is IMHO critical. Basically, if they run into an issue during design (and they will; their current mass fraction budget for what is really akin to a shuttle-type orbiter plus internal fuel) is beyond ambitious, so much so that I don’t think it’s possible. So, if (when) they run into, during design and testing, realities that force some added weight, they won’t be forced into radical engineering in order to shave off every ounce; they have the option of just scaling the first stage as needed.

    They’ve even said that the BFS (stripped, I assume) could do SSTO. That’s indicative of the mass fractions they are currently aiming for, which will include things like a TPS, wings, solar arrays, life support, cooling radiators, etc, that launch vehicles currently don’t (and still can’t do SSTO). However, if they can come close, such as being able to go suborbital while equipped to carry passengers for an hour, they’ll make their point-to-point transport idea vastly more viable. (no first stage needed).

      1. It’d make more sense just to move on to even bigger scaled-up Raptors and a design like the 2016 ITS, but with the BFR-type stubby wings.

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