Wjolcz Posted August 2, 2019 Share Posted August 2, 2019 (edited) 15 minutes ago, Flying dutchman said: What do you all think elon has changed about the fin design? It looked like a pretty good design to me.. Edit: really i've been dying to find out more about this. Aren't the fins of the booser stage meant to hold the engines now? I doubt they did the same, or anything, to the upper stage. Upper stage/Starship major changes: ceramic tiles instead of stainless steel ones. Also no active film cooling, or whatever it's called. Edited August 2, 2019 by Wjolcz Quote Link to comment Share on other sites More sharing options...
tater Posted August 2, 2019 Share Posted August 2, 2019 15 minutes ago, Wjolcz said: Upper stage/Starship major changes: ceramic tiles instead of stainless steel ones. Also no active film cooling, or whatever it's called. He has not said this, they put some test ceramic tiles on Dragon, that doesn't mean that is what they are using. Also, there are places where they might need ceramic even if they use active cooling elsewhere. Short answer is we don't know. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted August 2, 2019 Share Posted August 2, 2019 11 hours ago, tater said: This require Florida overflight. But yes starship landing will require overflight or an long boat trip. Or they need to build something offshore and that would have to be massive. 39 minutes ago, tater said: He has not said this, they put some test ceramic tiles on Dragon, that doesn't mean that is what they are using. Also, there are places where they might need ceramic even if they use active cooling elsewhere. Short answer is we don't know. For the first runs having something ablative would be nice as it shows heating. Benefit of liquid cooling is that you can just add more fuel for cooling if coming in fast, yes this adds weight but only then coming fast. Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted August 2, 2019 Share Posted August 2, 2019 It's interesting that airplanes are not allowed to boom people over land, but spaceships are. (I know there is some effort right now to change the rules about airplanes flying supersonic over land.) Quote Link to comment Share on other sites More sharing options...
tater Posted August 2, 2019 Share Posted August 2, 2019 8 minutes ago, magnemoe said: This require Florida overflight. Yeah, interesting. Presumably the reentry danger area would be set offshore (just) and the craft corrects this to land at LZ-1? 7 minutes ago, mikegarrison said: It's interesting that airplanes are not allowed to boom people over land, but spaceships are. (I know there is some effort right now to change the rules about airplanes flying supersonic over land.) Yeah, I've read that the ban was sort of evidence-free, but regardless, it's now apparently possible to mitigate sonic boom intensity for aircraft. I think the principle difference here is that the footprint for loud booms is pretty small for rockets (the cone trails the object, so if the object is moving vertically downwards the boom is a circle, not continuous over the ground). Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted August 2, 2019 Share Posted August 2, 2019 5 minutes ago, tater said: Yeah, I've read that the ban was sort of evidence-free, but regardless, it's now apparently possible to mitigate sonic boom intensity for aircraft. More "claimed to be possible" than "proven to be possible". The draft EIS specifies 24 launches per year. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted August 2, 2019 Share Posted August 2, 2019 10 minutes ago, mikegarrison said: It's interesting that airplanes are not allowed to boom people over land, but spaceships are. (I know there is some effort right now to change the rules about airplanes flying supersonic over land.) Well rockets are kind of noisy going up too so they have an exception. Yes this assumes an launch each month or similar. For planes you have multiple flights each hours. Better aerodynamic and higher attitude will reduce the noise level from supersonic planes a lot. P2P starship will run into this full force however. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted August 2, 2019 Share Posted August 2, 2019 A HS/HL drags the shockwave across the land. Probably, shuttles did. Quote Link to comment Share on other sites More sharing options...
tater Posted August 2, 2019 Share Posted August 2, 2019 (edited) 39 minutes ago, mikegarrison said: The draft EIS specifies 24 launches per year. Yeah (wow). Starlink, presumably. From the sonic boom standpoint, this is not really all that bad, however. A few sonic booms a month is not like what they were discussing (the FAA) with supersonic flight over the country (multiple booms a day for everyone in the country). 11 minutes ago, kerbiloid said: A HS/HL drags the shockwave across the land. Probably, shuttles did. I heard Columbia the morning she broke up, actually. I thought a large bird had hit the picture window in the living room (that was in fact the sonic boom after she passed ABQ), and walked out on the patio expecting to see a hawk staggering around, but there was no bird print on the window, and no brid on the patio... then I heard a rumbling. Went inside to hear on the radio that there was an issue with Shuttle... Edited August 2, 2019 by tater Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted August 2, 2019 Share Posted August 2, 2019 Won’t large fins near Super Heavy’s base create issues with the location of the centre of pressure? On a returning F9 booster, the COP is near the top because of the drag of the grid fins. This keeps it going engines-first. With the Super Heavy, it’ll have four grid fins near the top, but also three big fins near the base of the booster. As far as I can see, the fins will cause the COP to move somewhere closer to the base of the booster, causing its stable descent orientation to be different. Can someone more knowledgable please explain how this will work to me? Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted August 2, 2019 Share Posted August 2, 2019 40 minutes ago, RealKerbal3x said: Won’t large fins near Super Heavy’s base create issues with the location of the centre of pressure? On a returning F9 booster, the COP is near the top because of the drag of the grid fins. This keeps it going engines-first. With the Super Heavy, it’ll have four grid fins near the top, but also three big fins near the base of the booster. As far as I can see, the fins will cause the COP to move somewhere closer to the base of the booster, causing its stable descent orientation to be different. Can someone more knowledgable please explain how this will work to me? From what I’ve seen, the bottom “fins” of the booster will still be pretty small, and also (probably) non-movable. And close to the COM, while the upper grid fins are far (really) far, and move for control authority. I think the fixed fins will be more analogous to the wings on an airplane, with the grid fins like the “tail.” Superheavy should be able to “glide” better that way. BO is doing something similar with NG. Even the Falcon 9 booster glides, tho not very well. You can see it very plainly in the most recent launch footage. More gliding=less fuel used for boostback. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted August 2, 2019 Share Posted August 2, 2019 1 hour ago, CatastrophicFailure said: From what I’ve seen, the bottom “fins” of the booster will still be pretty small, and also (probably) non-movable. And close to the COM, while the upper grid fins are far (really) far, and move for control authority. I think the fixed fins will be more analogous to the wings on an airplane, with the grid fins like the “tail.” Superheavy should be able to “glide” better that way. BO is doing something similar with NG. Even the Falcon 9 booster glides, tho not very well. You can see it very plainly in the most recent launch footage. More gliding=less fuel used for boostback. Ah yeah, I failed to factor in that the COM is near the base of Super Heavy because of the mass of all of the engines. And I’ve got another question...will it ever be necessary for Super Heavy to land at sea? All of the animations we’ve got so far show it doing an RTLS. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted August 2, 2019 Share Posted August 2, 2019 Just now, RealKerbal3x said: Ah yeah, I failed to factor in that the COM is near the base of Super Heavy because of the mass of all of the engines. And I’ve got another question...will it ever be necessary for Super Heavy to land at sea? All of the animations we’ve got so far show it doing an RTLS. The Environmental thing specifies Super Heavy landing on an ASDS, but only 20 nautical miles from shore. Later on they will almost certainly get permission for an RTLS. This might be for sonic boom mitigation and testing (don't want a giant untested rocket hurtling towards what is probably the most significant launch pad ever right out of the gate). But this will prove that it's possible to do ASDS... It might be useful for missions that borderline don't need refueling to get some extra margin, like Dear Moon. Quote Link to comment Share on other sites More sharing options...
Nightside Posted August 2, 2019 Share Posted August 2, 2019 Although an onshore landing is surely much cheaper and faster, it is a hazard to other pads, they have opted to land on a barge to avoid these conflicts before. Will they need a bigger ASDS? Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted August 2, 2019 Share Posted August 2, 2019 1 hour ago, Nightside said: Will they need a bigger ASDS? Maybe they’re gonna bolt together OCISLY with the soon-to-arrive JRTI. A mega drone called Just Course Of The Love Read You Instructions, I. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted August 2, 2019 Share Posted August 2, 2019 The droneship can take the weight. Empty rockets are lighter than many cargo containers or whatever you would put on a barge that size. Whether or not it can support all that weight on 3 or 4 footpads, though, I don't know. As far as size, its unknown due to how little we know about the legs, but they want to land sh on the pad someday, so it should be accurate enough to land if it's small enough, which it probably is. Maybe that's why they are bringing the droneship over... To modify it for sh operations. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted August 2, 2019 Share Posted August 2, 2019 The old Dragon is already obsolete. Quote Link to comment Share on other sites More sharing options...
tater Posted August 2, 2019 Share Posted August 2, 2019 The span of F9 booster is ~15m. Starship might fit unmodified, though will less slop. Quote Link to comment Share on other sites More sharing options...
Nightside Posted August 2, 2019 Share Posted August 2, 2019 30 minutes ago, CatastrophicFailure said: The old Dragon is already obsolete. That old hunk of junk? Maybe time to buy one and mod it up for a Kessel run or two. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted August 2, 2019 Share Posted August 2, 2019 32 minutes ago, Nightside said: That old hunk of junk? Maybe time to buy one and mod it up for a Kessel run or two. Probably has all sorts of books & crannies for smuggling absolutely legitimate freight transit, too... Now to invent the hyperdrive.... I suggest starting with a sugared-up toddler... Quote Link to comment Share on other sites More sharing options...
Guest Posted August 3, 2019 Share Posted August 3, 2019 8 hours ago, tater said: I heard Columbia the morning she broke up, actually. I thought a large bird had hit the picture window in the living room (that was in fact the sonic boom after she passed ABQ), and walked out on the patio expecting to see a hawk staggering around, but there was no bird print on the window, and no brid on the patio... then I heard a rumbling. Went inside to hear on the radio that there was an issue with Shuttle... :( Quote Link to comment Share on other sites More sharing options...
Guest Posted August 3, 2019 Share Posted August 3, 2019 (edited) 2 hours ago, CatastrophicFailure said: The old Dragon is already obsolete. Yes... that's the whole idea >_< And SpaceX needs to get the new Dragons out the door and into service ASAP, before Starship finishes its development because then Falcon becomes obsolete @_@. Spoiler Edited August 3, 2019 by Guest Quote Link to comment Share on other sites More sharing options...
Xd the great Posted August 3, 2019 Share Posted August 3, 2019 32 minutes ago, Dale Christopher said: Yes... that's the whole idea >_< And SpaceX needs to get the new Dragons out the door and into service ASAP, before Starship finishes its development because then Falcon becomes obsolete @_@. Reveal hidden contents Yeah, we had some problems with the Crew Dragon, so we just moved on with Crew Starship. What do you mean by violation of contract? Spoiler SpaceX offers to send cargo to ISS at a price of 20 million dollars per flight. "I know we violated the last contract, so we are offering discounts to NASA". Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted August 3, 2019 Share Posted August 3, 2019 9 hours ago, Nightside said: Will they need a bigger ASDS? = Will they need wider legs? Is a landed Starship much taller than landed Falcon? Quote Link to comment Share on other sites More sharing options...
tater Posted August 3, 2019 Share Posted August 3, 2019 16 minutes ago, kerbiloid said: Is a landed Starship much taller than landed Falcon? Falcon 9 (all of it, with fairing) is slightly taller than Super Heavy stage 1. F9 stage 1 is about 14m shorter than Starship (with fins). Quote Link to comment Share on other sites More sharing options...
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