NSEP Posted April 22, 2018 Share Posted April 22, 2018 (edited) Here is a little bit of a recap of the things we know about BFR, and how much SpaceX is worth. Development of the BFR is going strong, can't wait to see the test firing of the fully developed raptor engine, and what the BFR will truely look like. Edited April 22, 2018 by NSEP Quote Link to comment Share on other sites More sharing options...
SpacePigeon Posted April 22, 2018 Share Posted April 22, 2018 34 minutes ago, NSEP said: Development of the BFR is going strong, can't wait to see the test firing of the fully developed raptor engine, and what the BFR will truely look like. Excitement is really bubbling inside me. I just can't wait! Quote Link to comment Share on other sites More sharing options...
NSEP Posted April 22, 2018 Share Posted April 22, 2018 This video claims that the Upper Stage recovery is just an experiment, and to be honest, experimentation with different methods of reusability is excellent. Quote Link to comment Share on other sites More sharing options...
Jaff Posted April 22, 2018 Share Posted April 22, 2018 Why don’t they just wait until BFR is built and then go and fetch the upper stages left up there? Bfr up - satalite bfr down - spent upper F9 stages Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted April 22, 2018 Share Posted April 22, 2018 1 minute ago, Jaff said: Why don’t they just wait until BFR is built and then go and fetch the upper stages left up there? Bfr up - satalite bfr down - spent upper F9 stages At that point it probably wouldn't be worth it because they would be phasing out F9 anyway... And the years of radiation wouldn't be good for the stage. Plus, many of the stages would be in elliptical orbits, and might be tumbling due to lack of control. rendezvous/docking with an uncontrollable and potentially spinning object is pretty difficult. I've also heard that S2 is "only" worth about 15 million dollars. BFR flights could be worth it once the price goes down, but by the time the price goes down F9 will have been phased out. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted April 22, 2018 Share Posted April 22, 2018 2 minutes ago, Jaff said: Why don’t they just wait until BFR is built and then go and fetch the upper stages left up there? Bfr up - satalite bfr down - spent upper F9 stages Because there aren’t any. The upper stage automatically deorbits itself after the mission, usually over the Indian Ocean (for LEO flights from KSC). The recovery experiment is probably to gather data and perhaps test material for BFR. Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted April 22, 2018 Share Posted April 22, 2018 (edited) 7 minutes ago, Jaff said: Why don’t they just wait until BFR is built and then go and fetch the upper stages left up there? Bfr up - satalite bfr down - spent upper F9 stages While that is a great idea, there are a few issues with that plan: 1. Hoping the BFS has enough dV left to match orbits with a stage. 2. BFR/S is supposed to replace F9/H. So there would not be much point in recovering F9US by then, and many probably would have decayed out of orbit by then. 3. The technical details of catching a stage that has no attitude control or even power, being dead in space Edit: ninja'd by Ultimate Steve, as well as what CatastrophicFailure said Edited April 22, 2018 by StrandedonEarth Quote Link to comment Share on other sites More sharing options...
Wjolcz Posted April 22, 2018 Share Posted April 22, 2018 They actually used the roomba to secure the stage this time? Quote Link to comment Share on other sites More sharing options...
DAL59 Posted April 22, 2018 Share Posted April 22, 2018 Please Elon... Quote Link to comment Share on other sites More sharing options...
zolotiyeruki Posted April 23, 2018 Share Posted April 23, 2018 I just had a thought about the "bouncy castle" comment. The earlier comments in this thread make it sound like the bouncy castle is on the water for the 2nd stage to fall into. But what if it's like the Mars Pathfinder, where the bouncy castle is surrounding the craft you're trying to recover? Sure, it's more mass you have to loft into orbit, but it also means re-entry doesn't need to be as precise or controlled as a RTLS or droneship landing. Quote Link to comment Share on other sites More sharing options...
tater Posted April 23, 2018 Share Posted April 23, 2018 That has been suggested before, and it seems reasonable. The only issue is that he said bouncy castle before, then we saw Mr. Steven. Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 Maybe he wants the Stage to land on airbags because it's heavier than the fairing and a boat can't catch it from freefall or when it comes down under a parachute. The airbags might also be floatation devices for waterlandings. Quote Link to comment Share on other sites More sharing options...
Wjolcz Posted April 23, 2018 Share Posted April 23, 2018 (edited) I'm struggling to imagine how ballutes only would make the landing possible. It either needs to have a parafoil or engines to land itself. And I feel like using Mr. Stevens (or something similar) is the best way to catch it since ocean water would probably corrode the engine even if it had ballutes to keep it afloat. Edited April 23, 2018 by Wjolcz Quote Link to comment Share on other sites More sharing options...
NSEP Posted April 23, 2018 Share Posted April 23, 2018 Im geussing Stage 2 will land using this, but im not sure. Elon said that will land on a bouncy castle, not using a bouncy castle, so im a bit unsure. Quote Link to comment Share on other sites More sharing options...
zolotiyeruki Posted April 23, 2018 Share Posted April 23, 2018 When he said on a bouncy castle, it could land on a bouncy castle in the same way as you might land on your feet. There's definitely some linguistic liberties that could be taken here. Quote Link to comment Share on other sites More sharing options...
Wjolcz Posted April 23, 2018 Share Posted April 23, 2018 (edited) 2 hours ago, NSEP said: Im geussing Stage 2 will land using this, but im not sure. Elon said that will land on a bouncy castle, not using a bouncy castle, so im a bit unsure. I don't think they are sure either. He posted a "want to hear people's ideas" tweet (sorry, i'm too lazy to find it). My guess is they are still figuring this one out and there's no final design yet. But he also said it's all about weight so my bet is Mr. Stevens will catch second stage. Airbags need to be sturdier than parafoil so they probably weigh more too. But then they could use a simple parachute and use the heat shield (that also encompasses the engine) as the "bouncy castle" +retro thrusters (like on Soyuz and the New Shepherd capsule). That would probably damage the engine nozzle though. Anyway, I don't know. Here are my guesses. Really excited for whatever they come up with. Edited April 23, 2018 by Wjolcz Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 Or they could put an inflatable heatshield on the front, inside the payload adapter, and reenter that way to protect the engine, then deploy parachutes out from the engine-end of the stage to slow down for a "bounce" on whatever they have floating on the water; that could be a ship like ASDS with a "blow-up-landing-cushion" instead of a landing pad; maybe even both, so the ASDS become dual use depending on what you want to land on it. Quote Link to comment Share on other sites More sharing options...
tater Posted April 23, 2018 Share Posted April 23, 2018 The problem with erecting a bouncy castle around the stage is that they really need to keep all sea water out. So if there is a chance of water exposure, they might have just obviated any reuse benefit due to increased refurb costs. Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 Maybe this is all barking up the wrong tree anyway. Since that upper stage goes into some kind of orbit anyway, couldn't they have it come around entirely and, you know, "land" it properly, like, on land? That would solve the sea water issue completely... There's some nice large desert areas in the US where that wouldn't be so bad I guess. Quote Link to comment Share on other sites More sharing options...
tater Posted April 23, 2018 Share Posted April 23, 2018 Just now, Kr0noZ said: Maybe this is all barking up the wrong tree anyway. Since that upper stage goes into some kind of orbit anyway, couldn't they have it come around entirely and, you know, "land" it properly, like, on land? That would solve the sea water issue completely... There's some nice large desert areas in the US where that wouldn't be so bad I guess. Wow, that's an interesting idea. The current model is that the recovery ship, Mr. Steven, has to chase down the chute and do some of the work. I'm unsure how accurate they can deliver a parachute. I wonder how big you could make a circus net? Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 (edited) Well yeah, but a ship can do what, 30 knots? 35 knots? I understand that would be some serious speed for a ship, but it's actually not that fast; about 65 km/h. So they'd have to either be pretty much on point already or deploy the chute so high up that the stage falls under it for a loooooooooong time to allow the ship to snail into position. If they have enough accuracy for that, I'd imagine targeting some place on the ground would be possible as well. Maybe stick some of those fancy grid fins to the stage for terminal guidance before the chute opens, you should get to within a few hundred meters. And if you make the bouncy house mobile, land vehicles CAN be pretty quick if there's nothing in the way to care about. As for the net, pretty large I imagine, although you'd have to put it up rather high to allow it to stretch when it gets whacked by several tons of spacecraft. Also, this: https://en.wikipedia.org/wiki/Joint_Precision_Airdrop_System Steerable chutes seem to be a thing, and this system gets to under 100m accuracy apparently. Maybe borrow from that somehow? Edited April 23, 2018 by Kr0noZ Quote Link to comment Share on other sites More sharing options...
tater Posted April 23, 2018 Share Posted April 23, 2018 So buy a ranch someplace remote, and build the biggest possible net... a few hundred meters across. That guy who skydived without a chute went into a net only ~30x30m. I'd think you'd want something closer to a half km... Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 Somehow that sounds like something Elon might do Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted April 23, 2018 Share Posted April 23, 2018 23 minutes ago, tater said: So buy a ranch someplace remote, and build the biggest possible net... a few hundred meters across. That guy who skydived without a chute went into a net only ~30x30m. I'd think you'd want something closer to a half km... Like Hawthorne? Where they’ve got a bunch of test and support equipment already? Quote Link to comment Share on other sites More sharing options...
Kr0noZ Posted April 23, 2018 Share Posted April 23, 2018 Isn't that a part of LA or something? Right next to LAX? I don't see them being cool with dropping rockets on a massive city... Quote Link to comment Share on other sites More sharing options...
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