zolotiyeruki Posted September 4, 2020 Share Posted September 4, 2020 Did the parachutes not deploy on these fairing halves? Seems like if it was just a missed catch, they'd still be intact, if water-logged. Quote Link to comment Share on other sites More sharing options...
Codraroll Posted September 4, 2020 Share Posted September 4, 2020 How did they get the broken fairings into the net if they didn't land there? I don't see how the boat is equipped to take fairings from the water and putting them inside the raised net. Were they scooped out of the sea, put on top of the folded net, which was extended afterwards? If so, why? Quote Link to comment Share on other sites More sharing options...
sh1pman Posted September 5, 2020 Share Posted September 5, 2020 Human for scale. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted September 5, 2020 Share Posted September 5, 2020 Guysguysguysguysguysguys... Quote Link to comment Share on other sites More sharing options...
cubinator Posted September 5, 2020 Share Posted September 5, 2020 I wonder if the RVac will "wiggle" as much as MVac does. Is the nozzle as thin? Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted September 5, 2020 Share Posted September 5, 2020 1 hour ago, cubinator said: I wonder if the RVac will "wiggle" as much as MVac does. Is the nozzle as thin? Doesn’t look like it. Looks to be almost entirely fluid cooled, so lots of little tubes that will add rigidity. The Merlin’s vac bell is so thin you could dent it with a hammer (or trim it with shears on the rocket in a pinch... ). Quote Link to comment Share on other sites More sharing options...
AVaughan Posted September 5, 2020 Share Posted September 5, 2020 (edited) 13 hours ago, sevenperforce said: I did some math on thrust balancing for a 1+7 configuration (because, again, it is super compact). I assumed a minimum throttle of 40% and a max thrust of 2200 kN. Assuming a 300-tonne-empty booster, there's actually no way to successfully hover with the 1+7 configuration. The closest you can come is lighting three engines as shown in the center. You'd think it would work (three engines at 40% gives about 0.9 gees), but the topmost engine cannot throttle below 73% or the thrust will be unbalanced. So either you hoverslam every time, or you use a different configuration. I'm assuming the above is with superheavy vertical, and without any thrust vectoring? There is the option of thrust vectoring which should get you a little closer to hovering, even with superheavy upright. Taking the centre diagram you should be able to tilt the 40-55% pair away from each other. 8 degrees of thrust vectoring mean the cosine loss is about 1%, which would allow the third engine to throttle lower. That gets you a little closer to hovering. There is also the possibility of hovering with superheavy canted over. Taking the centre diagram, tilt SH so its COM is offset slightly towards the bottom pair of engines. If you have the right amount of tilt, then the third engine should be able to throttle to match the bottom pair. (I'm not sure how much tilt that is, but I'm guessing it is around 5 degrees). This should also give you the full throttle range of all 3 engines, so 2640-6600kN. (A 2 engine hover should also be possible). Edited September 5, 2020 by AVaughan Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted September 5, 2020 Share Posted September 5, 2020 (edited) Edited September 5, 2020 by CatastrophicFailure Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 5, 2020 Share Posted September 5, 2020 Full size image: That's rocket porn right there Anyway, SN7.1 is getting ready to head to the launch site, and I for one can't wait for it to pop at record pressure! Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 5, 2020 Share Posted September 5, 2020 12 hours ago, Codraroll said: How did they get the broken fairings into the net if they didn't land there? I don't see how the boat is equipped to take fairings from the water and putting them inside the raised net. Were they scooped out of the sea, put on top of the folded net, which was extended afterwards? If so, why? No if fished out of the water or even after getting in the net they are put in an cradle on the deck, you can often see this then they return to port. My guess is that the fairing hit one of the arms holding up the net so almost an miss. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 6, 2020 Share Posted September 6, 2020 Awesome comparison of all three Starship 150m hops! The improvement in Raptor TWR is very visible between Starhopper and SN5/SN6. Also, finally some closeup views of SN6 post-hop. I hope SN5 gets better legs for its second hop, because one got totally crushed this time. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 6, 2020 Share Posted September 6, 2020 B1060.2 is returning to port! Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 7, 2020 Share Posted September 7, 2020 SN6 is preparing to head back to the launch site while SN7.1 is almost ready for its pop test: Quote Link to comment Share on other sites More sharing options...
KSK Posted September 7, 2020 Share Posted September 7, 2020 31 minutes ago, RealKerbal3x said: SN6 is preparing to head back to the launch site while SN7.1 is almost ready for its pop test: Ah-ha! They’re not water towers, they’re giant Pringles (TM) tubes. ”Once you pop you won’t stop” Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 7, 2020 Share Posted September 7, 2020 SN6 makes the second return of a Starship to the build site! Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 7, 2020 Share Posted September 7, 2020 5 hours ago, KSK said: Ah-ha! They’re not water towers, they’re giant Pringles (TM) tubes. ”Once you pop you won’t stop” Hoping for less popping Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted September 7, 2020 Share Posted September 7, 2020 7 hours ago, KSK said: Once you pop you won’t stop Spoiler A Nightmare mode: Spoiler Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted September 7, 2020 Share Posted September 7, 2020 On 9/4/2020 at 8:27 PM, CatastrophicFailure said: Guysguysguysguysguysguys... Am I right? Is that or isn’t that the most powerful vacuum engine ever manufactured? It’s more than twice the thrust of the J-2, and even the SSME’s vacuum thrust is slightly less. The F-1 had more vacuum thrust, of course, but it wasn’t a vacuum engine. I wonder if it is dual-bell. It doesn’t look dual bell but it is hard to tell. I do not think we have a sea level compensating bell like the RS-25. On 9/4/2020 at 8:31 PM, cubinator said: I wonder if the RVac will "wiggle" as much as MVac does. Is the nozzle as thin? As others have said, it won’t — both because the nozzle is not as thin, and because it will not gimbal. They could not use a radiatively cooled nozzle extension like the MVac because the engine is not directly exposed during the burn, due to Starship’s skirt/heat shield. The Raptor will be fixed in place and likely be in contact with the skirt. On 9/4/2020 at 11:31 PM, AVaughan said: I'm assuming the above is with superheavy vertical, and without any thrust vectoring? There is the option of thrust vectoring which should get you a little closer to hovering, even with superheavy upright. Taking the centre diagram you should be able to tilt the 40-55% pair away from each other. 8 degrees of thrust vectoring mean the cosine loss is about 1%, which would allow the third engine to throttle lower. That gets you a little closer to hovering. I assumed 15% gimbal range because that’s what Elon said. Cosine loss can go up to 3.41%, but that’s from the minimum throttle setting already which does not help as much. In other words, that’s 3.41%, not 3.41 percentage points. Not quite enough to get below one gee. Quote Link to comment Share on other sites More sharing options...
tater Posted September 7, 2020 Share Posted September 7, 2020 (edited) Tiles on SN6 all delaminated from their (white) substrate. Tiles (TPS period) are going to be non-trivial. Edited September 7, 2020 by tater Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted September 7, 2020 Share Posted September 7, 2020 46 minutes ago, sevenperforce said: Am I right? Is that or isn’t that the most powerful vacuum engine ever manufactured? Parts of the M1 got built, but I don't think there are Any other competitors unless there's something obscure and soviet I haven't heard about. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 7, 2020 Share Posted September 7, 2020 52 minutes ago, tater said: Tiles on SN6 all delaminated from their (white) substrate. Tiles (TPS period) are going to be non-trivial. So SN6's tiles were attached using adhesive? Shuttle-style? Despite their cracking, it appears that the tile attachment method used on SN5 is considerably more durable. Or maybe SN6 just landed that much harder. Quote Link to comment Share on other sites More sharing options...
RCgothic Posted September 7, 2020 Share Posted September 7, 2020 (edited) Sad: Edited September 7, 2020 by RCgothic Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 7, 2020 Share Posted September 7, 2020 1 hour ago, sevenperforce said: I wonder if it is dual-bell. It doesn’t look dual bell but it is hard to tell. I do not think we have a sea level compensating bell like the RS-25. If I know what you mean by dual-bell correctly (and I probably don't) then most likely not, considering that the RVac bells are meant to be stabilised against the thrust section skirt. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted September 7, 2020 Share Posted September 7, 2020 33 minutes ago, RealKerbal3x said: If I know what you mean by dual-bell correctly (and I probably don't) then most likely not, considering that the RVac bells are meant to be stabilised against the thrust section skirt. A dual bell nozzle is an ordinary nozzle with a circumferential kink/inflection point. At sea level, flow separation occurs at the inflection point. In vacuum it expands to fill the entire bell. Basically it is controlled flow separation. The RS-25 avoided flow separation by angling the nozzle in at the base to increased pressure at the expense of some underexpansion efficiency loss in vacuum. A dual bell accepts flow separation by essentially designating where it will occur. Info on a dual bell nozzle design Quote Link to comment Share on other sites More sharing options...
tater Posted September 8, 2020 Share Posted September 8, 2020 (Only good side by side I could find, but obviously his model for the 1D is lousy) And SL Merlin vs Raptor: Given the Rvac SN1 is set to go to McGreggor for testing, I wonder if the current nozzle is what works for testing without coming apart. They test Mvac engines minus the niobium extension there, and the Rvac is gonna need to be larger than the one shown I think (guestimating dia at what, ~2.5m (less than 2X SL bell). Quote Link to comment Share on other sites More sharing options...
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