tater Posted July 22, 2017 Share Posted July 22, 2017 Where's @sevenperforce to knock out some presumptive sketches of a 9m biconic vehicle? Quote Link to comment Share on other sites More sharing options...
tater Posted July 22, 2017 Share Posted July 22, 2017 Original design was 12m, with the gear bulges adding 5m (17m total at widest point). So if 9m is core diameter, it's 75% scale, if it's the widest point (likely not) it's 53% scale. Seems like the gear would be attached later. So call it a 9m core. Quote Link to comment Share on other sites More sharing options...
TheEpicSquared Posted July 22, 2017 Share Posted July 22, 2017 29 minutes ago, tater said: Where's @sevenperforce to knock out some presumptive sketches of a 9m biconic vehicle? He's probably over in the "Amateur rocket to orbit" thread. Quote Link to comment Share on other sites More sharing options...
tater Posted July 22, 2017 Share Posted July 22, 2017 Full size Raptor vac is around 4m. Raptor is under 2m. Looks like you could just fit 3 fixed vac engines, and 3 raptors all in a sort of 6 pointed star, alternating engines. The original design has 6 vacs, and 3 regular. So the regulars should be able to land if they throttle deep enough. Alternately, you could do 2 and 2, or rescale such that you get what you need. Quote Link to comment Share on other sites More sharing options...
tater Posted July 22, 2017 Share Posted July 22, 2017 Looks like from SpaceX drawings, regular raptor is actually about 1.5m diameter. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted July 23, 2017 Share Posted July 23, 2017 20 hours ago, magnemoe said: Think something like ITS would need an escape module with just the crew seating area. And as an escape capsule would be comparable with the full ship size, the only real way is systems redundancy, Like 8 engines instead of 4. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted July 23, 2017 Share Posted July 23, 2017 18 hours ago, tater said: Where's @sevenperforce to knock out some presumptive sketches of a 9m biconic vehicle? Coming up...... Quote Link to comment Share on other sites More sharing options...
Mighty1 Posted July 23, 2017 Share Posted July 23, 2017 How does the F9 second stage reignite? Does it have RCS, ulage or does it have some kind of internal systems for keeping fuel on the pumps? Quote Link to comment Share on other sites More sharing options...
StupidAndy Posted July 23, 2017 Share Posted July 23, 2017 16 minutes ago, Mighty1 said: How does the F9 second stage reignite? Does it have RCS, ulage or does it have some kind of internal systems for keeping fuel on the pumps? it might be pressure-fed..? Quote Link to comment Share on other sites More sharing options...
tater Posted July 23, 2017 Share Posted July 23, 2017 It could just be the already shown vehicle scaled down to 75%. The engines on the spacecraft would become 3 Raptor vac (4m dia), and 3 raptor (1.5m dia). Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted July 23, 2017 Share Posted July 23, 2017 21 minutes ago, Mighty1 said: How does the F9 second stage reignite? Does it have RCS, ulage or does it have some kind of internal systems for keeping fuel on the pumps? It has cold-gas nitrogen thrusters for roll control, attitude control during coast, and ullage. The nitrogen thrusters produce ullage and then a TEA-TEB shot is used to relight the engine. 5 minutes ago, StupidAndy said: it might be pressure-fed..? The Kestrel engine on the Falcon 1 was pressure-fed, but even it needed ullage and an ignition system. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted July 23, 2017 Share Posted July 23, 2017 Here are some potential layouts for the engine clusters on a 9-meter Raptor-based RHLV: Bottom is probable first stage configuration; top shows two different possibilities for the upper stage. The right-hand configuration is useful if they want more S2 thrust...e.g., for fully-loaded takeoffs (like from Mars or the Moon). A probable mission approach for Moon landings would be going alongside a tanker into a lunar free-return, transferring propellant from the tanker to the mission vehicle while still in transit, and then braking to capture and land with the mission vehicle while the tanker completes the free-return and comes back to Earth EDL. A 9-meter Raptor would be able to take even the largest Falcon Heavy payloads into LEO and beyond with full reuse. At this level, I think a payload bay would be a better idea than a separate payload fairing. Quote Link to comment Share on other sites More sharing options...
tater Posted July 23, 2017 Share Posted July 23, 2017 The previous architecture has the outer rings on stage 1 fixed, with the core engines with gimbal. I would say that 3 vac on S2 makes more sense, since the 12m version was going to TO on Mars, and land on Earth with just 3. 6 would be overkill. The downside of the US layouts are that the original design has the landing engines close to centerline, so an engine out might not be fatal. With the landing engines on the outside, that might be an issue. I suppose the vac engines could be moved outboard, with a fairing sort of like the landing leg strake/winglet/pods, only curved to cover the bells... just enough for a single Raptor on the centerline. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted July 23, 2017 Share Posted July 23, 2017 3 minutes ago, tater said: The previous architecture has the outer rings on stage 1 fixed, with the core engines with gimbal. I would say that 3 vac on S2 makes more sense, since the 12m version was going to TO on Mars, and land on Earth with just 3. 6 would be overkill. The downside of the US layouts are that the original design has the landing engines close to centerline, so an engine out might not be fatal. With the landing engines on the outside, that might be an issue. The one with two vacuum engines has far better engine-out landing capability. Tomorrow I'll try to throw together a mockup in KSP with liberal use of Tweakscale... Quote Link to comment Share on other sites More sharing options...
TheEpicSquared Posted July 23, 2017 Share Posted July 23, 2017 18 minutes ago, sevenperforce said: At this level, I think a payload bay would be a better idea than a separate payload fairing. I agree. Would save mass and money on a separate recovery system for the fairings. Also, less separation events, which means less failure points. Quote Link to comment Share on other sites More sharing options...
tater Posted July 23, 2017 Share Posted July 23, 2017 Do you see what I mean about putting some curved fairings on to shield the bells, and moving the Rvac engines just enough outboard to fit a center engine? Such a layout could also keep 3 Raptors, but tuck them far closer to center. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted July 23, 2017 Share Posted July 23, 2017 43 minutes ago, tater said: I would say that 3 vac on S2 makes more sense, since the 12m version was going to TO on Mars, and land on Earth with just 3. 6 would be overkill. The 12m version was going to take off from Mars with all nine engines. The Raptor Vacuum engines have no trouble taking off on Mars; the overexpansion is too minimal to make a difference. 43 minutes ago, tater said: The downside of the US layouts are that the original design has the landing engines close to centerline, so an engine out might not be fatal. With the landing engines on the outside, that might be an issue. Landing engines on the outside give better roll control on landing, something it would lack without grid fins. 43 minutes ago, tater said: I suppose the vac engines could be moved outboard, with a fairing sort of like the landing leg strake/winglet/pods, only curved to cover the bells... just enough for a single Raptor on the centerline. Like the shrouds on the Falcon 9v1.0? Seems unlikely, particularly because of how tough it would be to integrate into the interstage. And then you'd again have no roll control on the core engine. Not a problem in a vacuum, because the thrusters can handle it, but problematic during EDL (either on Mars or Earth). Grid fins would have virtually no bite on Mars but the drag would be high enough to demand roll authority. 38 minutes ago, TheEpicSquared said: I agree. Would save mass and money on a separate recovery system for the fairings. Also, less separation events, which means less failure points. Still potentially permits a cabin-eject LES. Not sure about how the bay closure seam would interact with the mold line and the heat shield, though. If they scrapped the Dragon 2 landing legs because of problems with popping through the heat shield, this would be an even bigger problem. Quote Link to comment Share on other sites More sharing options...
TheEpicSquared Posted July 23, 2017 Share Posted July 23, 2017 6 minutes ago, sevenperforce said: Still potentially permits a cabin-eject LES. Not sure about how the bay closure seam would interact with the mold line and the heat shield, though. If they scrapped the Dragon 2 landing legs because of problems with popping through the heat shield, this would be an even bigger problem. I have some ideas, I'll draw them when I get back home. Quote Link to comment Share on other sites More sharing options...
StupidAndy Posted July 23, 2017 Share Posted July 23, 2017 seriously where the heck is the Bulgariasat-1 landing footage!!?! its been over a month!! Quote Link to comment Share on other sites More sharing options...
RCgothic Posted July 24, 2017 Share Posted July 24, 2017 (edited) From what I've heard on Reddit, it was a ridiculously close call and insiders say they're not going to release it for PR reasons. Firstly, look at the scorch trail across the barge. Also the last frame shows spray being kicked up way off the mark. The rocket clearly pulled some crazy last minute manoeuvres. Secondly, insiders describe the booster balancing on one leg and nearly toppling. There is also a reference to CRS6 and the little thruster that couldn't. Apparently this time it could. So the video sounds ridiculously awesome, but don't hold out any hope for a release! Edited July 24, 2017 by RCgothic Quote Link to comment Share on other sites More sharing options...
TheEpicSquared Posted July 24, 2017 Share Posted July 24, 2017 21 minutes ago, RCgothic said: From what I've heard on Reddit, it was a ridiculously close call and insiders say they're not going to release it for PR reasons. Firstly, look at the scorch trail across the barge. Also the last frame shows spray being kicked up way of the mark. The rocket clearly pulled some crazy last minute manoeuvres. Secondly, insiders describe the booster balancing on one leg and nearly toppling. There is also a reference to CRS6 and the little thruster that couldn't. Apparently this time it could. So the video sounds ridiculously awesome, but don't hold out any hope for a release! *hopes harder* We all should keep spamming Musk on twitter about it until he answers Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted July 24, 2017 Share Posted July 24, 2017 Given the recent announcements about the D2 landing legs, nixing Red Dragon, and downscaling ITS, I can see why they might not want to make that release right now. Maybe in the future, when they have some better news to mix it with, like after a fully successful FH flight. That, or someone is eventually going to end up leaking it. Quote Link to comment Share on other sites More sharing options...
TheEpicSquared Posted July 24, 2017 Share Posted July 24, 2017 15 minutes ago, CatastrophicFailure said: That, or someone is eventually going to end up leaking it. I, for one, wouldn't mind that. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted July 24, 2017 Share Posted July 24, 2017 51 minutes ago, TheEpicSquared said: I, for one, wouldn't mind that. So would others, who have a lot more money than you to throw at it (I'm assuming ). Others' Questionable ethics aside, I think it would be far more wise for SpaceX to release it soon, on their own terms, vs the inevitable leak. Not that they listen to me. Quote Link to comment Share on other sites More sharing options...
tater Posted July 24, 2017 Share Posted July 24, 2017 I'd bet they might release it with a successful FH flight. Quote Link to comment Share on other sites More sharing options...
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