darthgently Posted July 19 Share Posted July 19 On 7/17/2024 at 5:52 PM, tater said: Those are first stage landing legs? I want to be like yay, but those seem overly complex with the internal storage. I'm not sure the booster spends enough time at speed in thick air to justify that kind of complex aero shielding. But I could easily be biased by the repeated success of the F9 leg design Quote Link to comment Share on other sites More sharing options...
tater Posted July 19 Share Posted July 19 1 hour ago, darthgently said: Those are first stage landing legs? I want to be like yay, but those seem overly complex with the internal storage. I'm not sure the booster spends enough time at speed in thick air to justify that kind of complex aero shielding. But I could easily be biased by the repeated success of the F9 leg design These are the legs they've shown since the beginning. But yeah, interesting choice. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted July 19 Share Posted July 19 1 hour ago, darthgently said: Those are first stage landing legs? I want to be like yay, but those seem overly complex with the internal storage. I'm not sure the booster spends enough time at speed in thick air to justify that kind of complex aero shielding. But I could easily be biased by the repeated success of the F9 leg design If they have internal space I don't see issues with it, 6 outer engines and 6 legs between them. now the aerodynamic cover for the pads I would probably redesign a bit, you are coming in fast and having the doors half open like that will not be practical. Have some sort of padding fin who also latch then fully open, simpler, lighter and much more damage resistant. Might simply have the legs push them open? Now Starship especially first stage looks very rough aerodynamically. You don't see this stuff on planes. Buts its an disposable prototype so it don't matter. Also drag is not an huge issue for huge rockets because the square cube law. Quote Link to comment Share on other sites More sharing options...
darthgently Posted July 19 Share Posted July 19 52 minutes ago, tater said: These are the legs they've shown since the beginning. But yeah, interesting choice. I never looked closely before. Just seems like more things to break to me. What chain of events could occur if one of six aero doors failed to open because of a seal or valve? Looks cool, but... Quote Link to comment Share on other sites More sharing options...
darthgently Posted July 19 Share Posted July 19 33 minutes ago, magnemoe said: If they have internal space I don't see issues with it, 6 outer engines and 6 legs between them. now the aerodynamic cover for the pads I would probably redesign a bit, you are coming in fast and having the doors half open like that will not be practical. Have some sort of padding fin who also latch then fully open, simpler, lighter and much more damage resistant. Might simply have the legs push them open? Now Starship especially first stage looks very rough aerodynamically. You don't see this stuff on planes. Buts its an disposable prototype so it don't matter. Also drag is not an huge issue for huge rockets because the square cube law. I would argue that even a mature Starship booster isn't going to need to be too concerned about drag at this level of detail. By the time the speed is piling on enough the air is also thinning rapidly with altitude. Similar reasoning seems to have already led to the non-folding grid fins. The extra mass and complexity of the aerodynamic version outweighs the increase in drag for the first stage from a performance perspective. A reusable 2nd stage is obviously a completely different consideration as more time is spent accelerating in atmo during ascent and re-entry from orbit puts aero at top of priorities Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted July 21 Share Posted July 21 (edited) Retractable landing gear is not some sort of mysterious country that has never been visited by man. I'm pretty sure they aren't a huge risk factor for landing. Probably not nearly as big a risk factor as trying to catch a rocket in mid-air as it hovers over the launch pad. Edited July 21 by mikegarrison Quote Link to comment Share on other sites More sharing options...
darthgently Posted July 22 Share Posted July 22 5 hours ago, mikegarrison said: Retractable landing gear is not some sort of mysterious country that has never been visited by man. I'm pretty sure they aren't a huge risk factor for landing. Sure, but the reason retractable landing gear exist is aerodynamics. It is just math. If the mass of the gear support systems costs more than the aero drag costs, performance-wise, then it doesn't matter if retractable gear are mature technology. Lightweight folding chairs are mature technology, but I don't carry a chair around with me all the time. No matter how cool it would look. Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted July 22 Share Posted July 22 1 hour ago, darthgently said: Sure, but the reason retractable landing gear exist is aerodynamics. It is just math. If the mass of the gear support systems costs more than the aero drag costs, performance-wise, then it doesn't matter if retractable gear are mature technology. Lightweight folding chairs are mature technology, but I don't carry a chair around with me all the time. No matter how cool it would look. There’s more to it than that. Legs act like fins; rockets head for landing tail-first. Massy engines first is good, but draggy stuff first is bad so while fixed legs would be good for stability on ascent, modern rockets don’t need that help, and it would need more control authority during descent. Ever try to land something too long behind the inflatable heat shield in KSP? Same problem… Quote Link to comment Share on other sites More sharing options...
darthgently Posted July 22 Share Posted July 22 22 minutes ago, StrandedonEarth said: There’s more to it than that. Legs act like fins; rockets head for landing tail-first. Massy engines first is good, but draggy stuff first is bad so while fixed legs would be good for stability on ascent, modern rockets don’t need that help, and it would need more control authority during descent. Ever try to land something too long behind the inflatable heat shield in KSP? Same problem… I'm not disagreeing with legs, just the complexity of internally stowed legs, as on a 747, for a first stage booster. One can theorize that externally stowed legs would make a tail first booster landing a big problem, but hundreds of actual F9 landings would be a powerful counterpoint to that theory. F9 legs are very low part count and quite straightforward mechanically compared to the internally stowed gear seen in the BO proto. I'm not arguing against legs, but against what I see as the overly-clever and high part count legs I'm seeing on the New Glenn proto. There is no reason for them to be internal on one extreme, nor is there a reason for them to be fixed in a down position at the other extreme. I think the SpaceX F9 externally stowed design maximizes the desirables. There is no reason BO couldn't use something similar given SpaceX's stance that as long as their ideas are used in good faith, they don't mind. As for the tower catching, I'm glad they are trying it, but will not be shocked if it ends up a dead end. If I absolutely had to bet I'd probably give it 65 to 70% chance of eventual success. But I'm not betting against SpaceX because they are the ones with the skin in the game, not me, and they have pulled a rabbit out of a hat before Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted July 22 Share Posted July 22 The gear design does appear overly complicated, more akin to aircraft landing gear. In comparison, SpaceX’s gear system is very simple, nitrogen pushers shove the legs out to get them started and multi-G deceleration does most of the actual work. This appears to be using hydraulics for active control. And that first door sticking out into a fast-moving airstream like that… Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted July 23 Share Posted July 23 Nothing for nothing... but math/physics guys, help me out. New Glenn is supposed to be 7m diameter and 98m tall. If the legs add a meter or two to the diameter of the rocket, and given that at landing most of the weight will be toward the bottom anyway, will it really be that much more stable? i.e. does a bottom-heavy 98m tall cylinder of 9m diameter really have that much more stability than a 7m cylinder? SX clearly doesn't think so, wrt SS. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted July 23 Share Posted July 23 31 minutes ago, JoeSchmuckatelli said: Nothing for nothing... but math/physics guys, help me out. New Glenn is supposed to be 7m diameter and 98m tall. If the legs add a meter or two to the diameter of the rocket, and given that at landing most of the weight will be toward the bottom anyway, will it really be that much more stable? i.e. does a bottom-heavy 98m tall cylinder of 9m diameter really have that much more stability than a 7m cylinder? SX clearly doesn't think so, wrt SS. Well you also add shock absorption and its 25% wider, you probably could not extend them straight down as the engine bells are there but rather higher up where its more room. SpaceX plan to catch SS with the arms. Not sure if any plans to add legs first? Could see them trying to land some other places before starbase as this require overflying US or Mexico. On 7/22/2024 at 7:41 AM, CatastrophicFailure said: The gear design does appear overly complicated, more akin to aircraft landing gear. In comparison, SpaceX’s gear system is very simple, nitrogen pushers shove the legs out to get them started and multi-G deceleration does most of the actual work. This appears to be using hydraulics for active control. And that first door sticking out into a fast-moving airstream like that… Yes I also reacted on the top door, this is pretty common on planes but they land slower and hatches tend to present an edge to air stream, planes also tend to fly multiple times a day so you want an solid system for this. Once was on a plane who had to turn around and land as nose wheel would not retract, it did extend again. As I understand its much easier to extend Quote Link to comment Share on other sites More sharing options...
tater Posted July 24 Share Posted July 24 Quote Link to comment Share on other sites More sharing options...
tater Posted July 27 Share Posted July 27 NET launch date is 29 September, 2024. Quote Link to comment Share on other sites More sharing options...
tater Posted August 3 Share Posted August 3 New Glenn at Port Canaveral—F9 for scale. Quote Link to comment Share on other sites More sharing options...
tater Posted August 8 Share Posted August 8 Quote Link to comment Share on other sites More sharing options...
tater Posted August 8 Share Posted August 8 This is Flight 1 hardware per BO CEO. Quote Link to comment Share on other sites More sharing options...
tater Posted August 8 Share Posted August 8 Sorry, image didn't get copied: Quote Link to comment Share on other sites More sharing options...
tater Posted August 8 Share Posted August 8 Quote Link to comment Share on other sites More sharing options...
AckSed Posted August 8 Share Posted August 8 The name's a little dull. You could say it has... a shortfall of gravitas. *flees* Quote Link to comment Share on other sites More sharing options...
Spaceception Posted August 12 Share Posted August 12 This is something to watch out for. Coming out on the 15th Glad to see Blue is becoming more open with info these days, I'll definitely be watching Quote Link to comment Share on other sites More sharing options...
AckSed Posted August 12 Share Posted August 12 My finger is on the pause button, the relevant NASASpaceflight thread is open and I have a notepad. Can't wait. Quote Link to comment Share on other sites More sharing options...
darthgently Posted August 13 Share Posted August 13 3 hours ago, Spaceception said: This is something to watch out for. Coming out on the 15th Glad to see Blue is becoming more open with info these days, I'll definitely be watching If BO has been trying to build suspense they have succeeded. This is so long overdue Quote Link to comment Share on other sites More sharing options...
AckSed Posted August 13 Share Posted August 13 I'm just hoping Bezos shares his O'Neill habitat plans with the nice viewers. Quote Link to comment Share on other sites More sharing options...
cubinator Posted August 13 Share Posted August 13 16 hours ago, darthgently said: If BO has been trying to build suspense they have succeeded. This is so long overdue Let's hope they've also succeeded in building a rocket! Quote Link to comment Share on other sites More sharing options...
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