Elthy Posted April 28, 2021 Share Posted April 28, 2021 2 hours ago, tater said: On the plus side 2 static fires, no change of engines. Did that ever happen? As far as i remember they allways had to swap one after the static fire... Quote Link to comment Share on other sites More sharing options...
KSK Posted April 28, 2021 Share Posted April 28, 2021 1 hour ago, RCgothic said: It had more to do with being unable to convince NASA that propulsive landing of a crew capsule was a good idea. Replying to @CastleKSide, I think the above had more to do with it. Maybe the landing gear was part of it too but given that Gemini B (for the Manned Orbiting Laboratory program) had a crew hatch in the heat shield, I'm not sure that deploying landing gear through the heat shield would have been such a big deal. If I remember rightly (half-remembered source), Gemini B was tested, so the hatch-in-the-heatshield was more than just an engineering mockup. Shuttle deployed its landing gear through the heatshield too of course but Gemini B seems more directly comparable. Quote Link to comment Share on other sites More sharing options...
SunlitZelkova Posted April 28, 2021 Share Posted April 28, 2021 10 minutes ago, Cuky said: Isn't it something like this: 1. Dragon Cargo Dragon (discontinued) Crew Dragon (planned at first, but never produced) 2. Dragon V2 Cargo Dragon Crew Dragon I haven't seen V2 Cargo Dragon ever referred to as Cargo Crew Dragon tbh. Though I heard them refer to it in live streams as a Dragon 2 Cargo variant and Dragon 2 Crew variant. It isn't, he probably used that because they use the same name but are clearly different, with Dragon 2-Cargo Dragon looking visually similar to the one and only Crew Dragon, whereas there are two Cargo Dragons that look very different. Wikipedia says it is "Dragon 2", with Cargo Dragon and Crew Dragon as the two variants. I have never heard of "V2" being used by either SpaceX or NASA. Quote Link to comment Share on other sites More sharing options...
YNM Posted April 28, 2021 Share Posted April 28, 2021 47 minutes ago, SunlitZelkova said: He probably used that because they use the same name but are clearly different, with Dragon 2-Cargo Dragon looking visually similar to the one and only Crew Dragon, whereas there are two Cargo Dragons that look very different. They removed the seats, instrument panel and LSS for the cargo version of Dragon 2. (reference in page 24.) 48 minutes ago, SunlitZelkova said: I have never heard of "V2" being used by either SpaceX or NASA. Yeah that was me. I mean there have been a lot of Dragons at this point so I was referring to the fact they've changed the design and not that it's the second one to fly. Quote Link to comment Share on other sites More sharing options...
Flying dutchman Posted April 28, 2021 Share Posted April 28, 2021 1 hour ago, SunlitZelkova said: I have never heard of "V2" being used by either SpaceX or NASA. Not even von Braun called it that. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted April 28, 2021 Share Posted April 28, 2021 (edited) 3 hours ago, Cuky said: haven't seen V2 Cargo Dragon ever referred to as Cargo Crew Dragon tbh. I haven't seen any reasonable SpaceX naming system yet, so I called it so to indicate what I mean. 3 hours ago, KSK said: Maybe the landing gear was part of it too but given that Gemini B (for the Manned Orbiting Laboratory program) had a crew hatch in the heat shield, I'm not sure that deploying landing gear through the heat shield would have been such a big deal. The hatch is not a problem. Four spears ramming the bottom of the capsule are. 3 hours ago, KSK said: Shuttle deployed its landing gear through the heatshield too of course but Gemini B seems more directly comparable. Not inside the crew if lands hard. 3 hours ago, SunlitZelkova said: I have never heard of "V2" being used by either SpaceX or NASA. https://en.wikipedia.org/wiki/RTV-G-4_Bumper https://en.wikipedia.org/wiki/PGM-11_Redstone 1 hour ago, Flying dutchman said: Not even von Braun called it that. Maybe Braun did when talking to bosses. As it was a propaganda name, and maybe they weren't aware of its real name. Edited April 28, 2021 by kerbiloid Quote Link to comment Share on other sites More sharing options...
tater Posted April 28, 2021 Share Posted April 28, 2021 4 hours ago, Elthy said: Did that ever happen? As far as i remember they allways had to swap one after the static fire... SN11 had 1 swap. SN10 had 1 swap. SN9 had 2 swaps. Quote Link to comment Share on other sites More sharing options...
RCgothic Posted April 28, 2021 Share Posted April 28, 2021 7 minutes ago, tater said: SN11 had 1 swap. SN10 had 1 swap. SN9 had 2 swaps. And SN8 melted one. Quote Link to comment Share on other sites More sharing options...
Flying dutchman Posted April 28, 2021 Share Posted April 28, 2021 54 minutes ago, kerbiloid said: Maybe Braun did when talking to bosses. As it was a propaganda name, and maybe they weren't aware of its real name. That's likely yes Quote Link to comment Share on other sites More sharing options...
tater Posted April 28, 2021 Share Posted April 28, 2021 Live in 14 hours. Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted April 28, 2021 Share Posted April 28, 2021 Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted April 28, 2021 Share Posted April 28, 2021 And if she's your fifteenth. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted April 28, 2021 Share Posted April 28, 2021 Quote Link to comment Share on other sites More sharing options...
SOXBLOX Posted April 28, 2021 Share Posted April 28, 2021 (edited) LOL to the above! 5 hours ago, kerbiloid said: Four spears ramming the bottom of the capsule are. Why do you think they would ram the bottom of the capsule? Pretty sure they'd have used shock absorbers. Edited April 28, 2021 by SOXBLOX Quote Link to comment Share on other sites More sharing options...
Deddly Posted April 28, 2021 Share Posted April 28, 2021 7 minutes ago, SOXBLOX said: LOL to the above! Why do you think they would ram the bottom of the capsule? Pretty sure they'd have used shock absorbers. I'm pretty sure those legs extended from the capsule to start with. As for why they did not go ahead with propulsive landing (and Red Dragon), the biggest reason Elon gave was that they decided to focus R&D on Starship instead because it would take almost as long to develop propulsive landing on Dragon and it would be almost immediately obsolete. Quote Link to comment Share on other sites More sharing options...
tater Posted April 28, 2021 Share Posted April 28, 2021 Propulsive landing ceased being worthwhile to follow through on when it was clear Crew Dragon would not use it. They had already decided to work on a next gen vehicle anyway I think. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted April 28, 2021 Share Posted April 28, 2021 1 hour ago, SOXBLOX said: Why do you think they would ram the bottom of the capsule? Pretty sure they'd have used shock absorbers. First two feet. Then pierce. On a hard landing the PTKNP legs will just break and fold, while the Dragon columns will be hammered by ground into the bottom of cabin. That's exactly why PTKNP got foldable legs. Quote Link to comment Share on other sites More sharing options...
SOXBLOX Posted April 28, 2021 Share Posted April 28, 2021 1 hour ago, kerbiloid said: On a hard landing the PTKNP legs will just break and... ...the kinetic energy will be transferred to the capsule and crew inside. Great. Anyways, it's a non-issue. They scrapped propulsive landing for Dragon. Had they gone through with it, who knows what it would have looked like. And now, I know Raptor uses electric ignition. But Merlin uses TEA/TEB. Why did they choose it over a spark gap, or some other method? Quote Link to comment Share on other sites More sharing options...
zolotiyeruki Posted April 28, 2021 Share Posted April 28, 2021 If a hypothetical dragon landing burn failed, wouldn't the landing legs be moot? I mean, if a capsule impacts at terminal velocity, I don't know that having the landing legs retracted is gonna save the occupants. Ah, I suppose if you had a mostly-good landing burn and the engines started just a bit late or cut out just a bit early, but that seems like a pretty narrow risk probability. Although I supposed Starship is proving me wrong, here. Quote Link to comment Share on other sites More sharing options...
SunlitZelkova Posted April 28, 2021 Share Posted April 28, 2021 10 hours ago, Flying dutchman said: Not even von Braun called it that. 8 hours ago, kerbiloid said: https://en.wikipedia.org/wiki/RTV-G-4_Bumper https://en.wikipedia.org/wiki/PGM-11_Redstone Maybe Braun did when talking to bosses. As it was a propaganda name, and maybe they weren't aware of its real name. Ok but the V2 and V2 based sounding rockets were all retired/used up by the time NASA was created. Maybe NASA History Office books used it, but it was never used in any official function by NASA! (You all may be joking, but to be clear, "I have never heard V2 used by SpaceX or NASA" was intended to be "I have never heard Dragon V2 used by SpaceX or NASA") Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted April 28, 2021 Share Posted April 28, 2021 20 minutes ago, SOXBLOX said: ...the kinetic energy will be transferred to the capsule and crew inside. Great. Absolutely normal. It's landing speed is 20 m/s before the landing engines get engaged. 1 m of legs + 30 cm of seat springs = 20 g. 1 minute ago, SunlitZelkova said: but it was never used in any official function by NASA! When it was NACA, maybe? 23 minutes ago, SOXBLOX said: Why did they choose it over a spark gap, or some other method? Maybe due to different fuels? 19 minutes ago, zolotiyeruki said: If a hypothetical dragon landing burn failed, wouldn't the landing legs be moot? I mean, if a capsule impacts at terminal velocity, I don't know that having the landing legs retracted is gonna save the occupants. Until they get smashed in. Quote Link to comment Share on other sites More sharing options...
SunlitZelkova Posted April 28, 2021 Share Posted April 28, 2021 5 minutes ago, kerbiloid said: When it was NACA, maybe? The V2 sound rocket tests, including the Bumper, were all conducted by the US Army, so I don't think so. A number of laboratories across the country participated in the launches but not NACA. Quote Link to comment Share on other sites More sharing options...
tater Posted April 28, 2021 Share Posted April 28, 2021 Quote Link to comment Share on other sites More sharing options...
SOXBLOX Posted April 28, 2021 Share Posted April 28, 2021 Wow. I wonder how many launches they can eke out. 15 would be cool to see... Quote Link to comment Share on other sites More sharing options...
magnemoe Posted April 28, 2021 Share Posted April 28, 2021 1 hour ago, SOXBLOX said: ...the kinetic energy will be transferred to the capsule and crew inside. Great. Anyways, it's a non-issue. They scrapped propulsive landing for Dragon. Had they gone through with it, who knows what it would have looked like. And now, I know Raptor uses electric ignition. But Merlin uses TEA/TEB. Why did they choose it over a spark gap, or some other method? Raptor uses methane / LOX who is much easier to mix and ignite than RP1 (kerosene), you have an separate ignition chamber and use gas methane and oxygen who works just like TEA in Merlin into the engine. H2/ LOX also tend to use spark plugs Quote Link to comment Share on other sites More sharing options...
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