sevenperforce Posted September 8, 2020 Share Posted September 8, 2020 24 minutes ago, tater said: 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). I am not so sure. The chamber pressure of the Merlin is just 1410 psi vs the Raptor at up to 4800 psi. The higher the chamber pressure, the less nozzle extension you need. I'm inclined to think that is in fact the full-size engine bell. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted September 8, 2020 Share Posted September 8, 2020 Pixel counting of that side-by-side puts the bell diameters ratio at 1.78 (with some uncertainty due to foreshortening). Pixel counting of official SpaceX renders puts the ratio at 1.76 (lunar Starship landing shot) to 1.77 (Mars entry interface) to 1.8 (standard rear view). So I don't think we're going to see any larger extension. Quote Link to comment Share on other sites More sharing options...
tater Posted September 8, 2020 Share Posted September 8, 2020 Quote Link to comment Share on other sites More sharing options...
RCgothic Posted September 9, 2020 Share Posted September 9, 2020 SN10 gets an extra ring on its forward dome... Quote Link to comment Share on other sites More sharing options...
totalitor Posted September 9, 2020 Share Posted September 9, 2020 19 hours ago, sevenperforce said: I am not so sure. The chamber pressure of the Merlin is just 1410 psi vs the Raptor at up to 4800 psi. The higher the chamber pressure, the less nozzle extension you need. I'm inclined to think that is in fact the full-size engine bell. Is it: the higher chamber pressure, the more nozzle extension you need. Correct me if I am wrong. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 9, 2020 Share Posted September 9, 2020 18 minutes ago, totalitor said: Is it: the higher chamber pressure, the more nozzle extension you need. Correct me if I am wrong. Logic indicates you are correct with higher pressure you can have an larger nozzle before pressure become to low at the end. However you might want to go with smaller nozzles than optimum because of space constrains. Quote Link to comment Share on other sites More sharing options...
RCgothic Posted September 9, 2020 Share Posted September 9, 2020 Quote Link to comment Share on other sites More sharing options...
tater Posted September 9, 2020 Share Posted September 9, 2020 Quote Link to comment Share on other sites More sharing options...
Spaceception Posted September 9, 2020 Share Posted September 9, 2020 Do any of you think that the October presentation will lay out some expected milestones for Superheavy, and further ones for Starship? I've had some ideas lately, and they're going off on what we're seeing now with Starship testing, where they do low-altitude hops with min. engines (Starshopper, SN5, SN6), mid-altitude hops with the core engines (SN8? I heard there was something like a NOTAM which would imply a hop of several kilometers first, is that right?), and high-altitude hops that will prove out the landing profile (SN8? SN9+). We could also see have a series of dress rehearsal flights while Superheavy is testing, with the full heatshield, mass sims (at the least) for VacRap, and upgraded hardware in the flaps, legs, etc. So based on that, we know Superheavy is also going for a low altitude hop with min. engines for the first prototype. Afterward, they could go for a mid-altitude hop with the second prototype using the core cluster of 8 engines, so they can test that part of the thrust dome in-flight. And then a high-altitude hop, with at least several engines on the outer ring so they can get in-flight expectations on some of the stresses. This could possibly a sub-scale flight that goes through Max-Q (with a nosecone at least), heads downrange, shuts off its engines, and performs a boostback burn before landing on the pad. After that, BP4 of Superheavy could be the earliest expected booster to perform an orbital flight next year, assuming no catastrophic failure like SN1 or 4. I think any failure will come from the flights or landing though. They seem to be getting a good handle on the tanks since SN4, and Superheavy uses the same ones, albeit stretched and slightly thicker. Quote Link to comment Share on other sites More sharing options...
tater Posted September 9, 2020 Share Posted September 9, 2020 SH doesn't need that much testing for landing, it really needs testing for launch ops (full number of engines). Since it needs a large mass simulator on top—disposable SS, IMO. Throw a SS version (assuming there is one intact after flight testing) on top with Starlinks in it and fly. Offsets the cost, and the SS either has tiles, or they sacrifice it for data on ED(L) (not really any Landing if ED minus tiles). Quote Link to comment Share on other sites More sharing options...
RCgothic Posted September 9, 2020 Share Posted September 9, 2020 SN11 starts construction: Quote Link to comment Share on other sites More sharing options...
sh1pman Posted September 10, 2020 Share Posted September 10, 2020 Can they build Raptors as fast as they’re building new Starships? Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 10, 2020 Share Posted September 10, 2020 32 minutes ago, sh1pman said: Can they build Raptors as fast as they’re building new Starships? They are doing single engine jumps for this reason, some chance for rud and they just loose one engine. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 10, 2020 Share Posted September 10, 2020 8 hours ago, tater said: SH doesn't need that much testing for landing, it really needs testing for launch ops (full number of engines). Since it needs a large mass simulator on top—disposable SS, IMO. Throw a SS version (assuming there is one intact after flight testing) on top with Starlinks in it and fly. Offsets the cost, and the SS either has tiles, or they sacrifice it for data on ED(L) (not really any Landing if ED minus tiles). its work like an falcon 9 but its another much larger rocket with another engine. they need to modify the F9 algorithm for landing. No mass simulator unless dummy engines to add weight at bottom. Now for higher jump with SH they might need an nose cone and then drop it for landing? Or just land with it or jump without. And they need full engine stack burns as in the new concrete pad, Build two as you might loose one. Quote Link to comment Share on other sites More sharing options...
tater Posted September 10, 2020 Share Posted September 10, 2020 23 minutes ago, magnemoe said: its work like an falcon 9 but its another much larger rocket with another engine. they need to modify the F9 algorithm for landing. No mass simulator unless dummy engines to add weight at bottom. I mean to test the full thing, all engines. GSE, etc. They want to not destroy launch pad, etc. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted September 10, 2020 Share Posted September 10, 2020 5 hours ago, sh1pman said: Can they build Raptors as fast as they’re building new Starships? Yes. 1 starship - 1 raptor. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted September 10, 2020 Share Posted September 10, 2020 SN11 isn't much yet, but it sure is coming! Quote Link to comment Share on other sites More sharing options...
tater Posted September 10, 2020 Share Posted September 10, 2020 (edited) Edited September 10, 2020 by tater Quote Link to comment Share on other sites More sharing options...
DDE Posted September 10, 2020 Share Posted September 10, 2020 4 hours ago, tater said: So they're milling and not brazing, eh? I wonder if everyone has done the math for these two processes from across the different side of the Iron Curtain. Quote Link to comment Share on other sites More sharing options...
tater Posted September 10, 2020 Share Posted September 10, 2020 Quote Link to comment Share on other sites More sharing options...
RCgothic Posted September 11, 2020 Share Posted September 11, 2020 Quote Link to comment Share on other sites More sharing options...
zolotiyeruki Posted September 11, 2020 Share Posted September 11, 2020 Is "aerocover" just a fancy name for "fairing"? Quote Link to comment Share on other sites More sharing options...
magnemoe Posted September 11, 2020 Share Posted September 11, 2020 22 minutes ago, zolotiyeruki said: Is "aerocover" just a fancy name for "fairing"? No this is more like the blend between the body and the flaps, much like the blend from body to wing on an plane, it will end in the hinges to the flaps. I assume they will go up all the way to the upper flaps as an raceway for piping and to break the shockwave away from body. Quote Link to comment Share on other sites More sharing options...
Meecrob Posted September 11, 2020 Share Posted September 11, 2020 ...which is a fairing. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted September 11, 2020 Share Posted September 11, 2020 The long and narrow aerodynamic detail from the cabin glass to the fin ("гаргрот") - is it a "fairing", too? Or what's her English name? Spoiler Quote Link to comment Share on other sites More sharing options...
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