tater Posted July 8, 2022 Share Posted July 8, 2022 Quote Link to comment Share on other sites More sharing options...
tater Posted July 9, 2022 Share Posted July 9, 2022 Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted July 9, 2022 Share Posted July 9, 2022 Quote Booster will either do a partial return and land in the Gulf of Mexico or do a full return with a catch attempt That's cool - hope we get to watch it either way (Like, they take out one of the Drone ships and land just off it, if it is a water landing) Quote Ship will reach about 250 km in altitude, then powered landing in the Pacific Why so high? Is that due to ballistic nature of the flight? Quote Link to comment Share on other sites More sharing options...
cubinator Posted July 9, 2022 Share Posted July 9, 2022 31 minutes ago, JoeSchmuckatelli said: Why so high? Is that due to ballistic nature of the flight? My guess is it is doing a burn with the same deltaV of a circular orbit insertion, but with an elliptical trajectory that carries it back into the atmosphere. Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted July 9, 2022 Share Posted July 9, 2022 Someone in western Cuba gonna have a good view. Quote Link to comment Share on other sites More sharing options...
RCgothic Posted July 9, 2022 Share Posted July 9, 2022 More on that: Quote Link to comment Share on other sites More sharing options...
tater Posted July 9, 2022 Share Posted July 9, 2022 Quote Link to comment Share on other sites More sharing options...
tater Posted July 9, 2022 Share Posted July 9, 2022 (edited) Wow, the finished Raptor 2 engines are so clean (of extraneous stuff). "A high production rate solves many ills" No torch ignitors in the main chamber. Edited July 9, 2022 by tater Quote Link to comment Share on other sites More sharing options...
tater Posted July 9, 2022 Share Posted July 9, 2022 They want to get rid of the hydraulics and go straight electric for actuators. Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted July 9, 2022 Share Posted July 9, 2022 (edited) 1 hour ago, tater said: They want to get rid of the hydraulics and go straight electric for actuators. Hmm, IIRC, Merlin could use the RP-1 fuel as hydraulic fluid. Somehow I don't think methane can be dual-purpose like that, so it makes sense to eliminate a separate fluid system. E: posted first, watched video later. Yup, that was covered. Methane is doable, but problematic due to low boiling point. Edited July 9, 2022 by StrandedonEarth Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted July 9, 2022 Share Posted July 9, 2022 They have also managed to eliminate the torch igniters for the main chamber. How they ignite the engine now is "secret sauce." Quote Link to comment Share on other sites More sharing options...
tater Posted July 9, 2022 Share Posted July 9, 2022 Quote Link to comment Share on other sites More sharing options...
tater Posted July 10, 2022 Share Posted July 10, 2022 Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted July 10, 2022 Share Posted July 10, 2022 (edited) Three flights a week, busier than many airline routes... Edited July 10, 2022 by StrandedonEarth tyo Quote Link to comment Share on other sites More sharing options...
Lukaszenko Posted July 10, 2022 Share Posted July 10, 2022 On 7/8/2022 at 6:20 PM, JoeSchmuckatelli said: Is there a 'ground effect' for a rocket that would make a practice 'hoover' over water different from what they'd see at the pad? I would guess not. I understand that ground effect is due to increased pressure of air when close to a surface (because the air is more constrained). Increased air pressure is good for wings, but not for rockets. Also, if ground effect did something, I would guess this would be mentioned when describing TWR, as arguably it is most important immediately on takeoff. Quote Link to comment Share on other sites More sharing options...
tater Posted July 10, 2022 Share Posted July 10, 2022 Quote Link to comment Share on other sites More sharing options...
tater Posted July 10, 2022 Share Posted July 10, 2022 Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted July 10, 2022 Share Posted July 10, 2022 On 7/9/2022 at 8:07 AM, tater said: 99% combustion efficiency is no big deal in a gas turbine. I'm not sure why Elon was so impressed by it. Quote Link to comment Share on other sites More sharing options...
tater Posted July 10, 2022 Share Posted July 10, 2022 Lightning tower going up. Quote Link to comment Share on other sites More sharing options...
Terwin Posted July 10, 2022 Share Posted July 10, 2022 56 minutes ago, mikegarrison said: 99% combustion efficiency is no big deal in a gas turbine. I'm not sure why Elon was so impressed by it. Wiki indicates that 70-90% is good for a turbopump: https://en.wikipedia.org/wiki/Turbopump#:~:text=Turbopumps have a reputation for,this is a severe problem. It looks like the efficiency problems are more with the fluid-handling side as opposed to the gas-turbine side(or at least all the listed issues seem to be related to fluid handling). Also, the 99% includes not just two gas turbines, but also the two pumps, the combustion chamber and the rest of the engine. Even if both turbines are at 99.9% that still means that the rest of the bits combined lose less than 0.9% total efficiency. Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted July 10, 2022 Share Posted July 10, 2022 45 minutes ago, Terwin said: Wiki indicates that 70-90% is good for a turbopump: https://en.wikipedia.org/wiki/Turbopump#:~:text=Turbopumps have a reputation for,this is a severe problem. It looks like the efficiency problems are more with the fluid-handling side as opposed to the gas-turbine side(or at least all the listed issues seem to be related to fluid handling). Also, the 99% includes not just two gas turbines, but also the two pumps, the combustion chamber and the rest of the engine. Even if both turbines are at 99.9% that still means that the rest of the bits combined lose less than 0.9% total efficiency. No, you are talking about the pumping efficiency. He specifically said "combustion efficiency". At 14:30 or so. Maybe rocket engines don't typically get the combustion efficiency of jet engines? I don't know, but 99% would be low for combustion efficiency in a jet engine. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted July 10, 2022 Share Posted July 10, 2022 39 minutes ago, Terwin said: Wiki indicates that 70-90% is good for a turbopump: https://en.wikipedia.org/wiki/Turbopump#:~:text=Turbopumps have a reputation for,this is a severe problem. It looks like the efficiency problems are more with the fluid-handling side as opposed to the gas-turbine side(or at least all the listed issues seem to be related to fluid handling). Also, the 99% includes not just two gas turbines, but also the two pumps, the combustion chamber and the rest of the engine. Even if both turbines are at 99.9% that still means that the rest of the bits combined lose less than 0.9% total efficiency. Gas turbines burn gas or atomized liquid in air and even jet engines uses cooled turbine blades, the large ones in power plants don't bother about weight. Turbopumps, Well burning gas in pure oxygen is an nice way to cut steel while the engine is small even compared to an small fighter jet engine and no working gas to cool the blades. And yes outside the space shuttle, new Shepard, falcon 9 and Starship all turbo pumps are single use. I assume efficiency on cruise missile jet engines is well below 99% as they are small and single use. Quote Link to comment Share on other sites More sharing options...
tater Posted July 11, 2022 Share Posted July 11, 2022 Should go live soon live RP-1 load complete ~3 min Er, closer to 2 Go for launch Liftoff (apparently) Quote Link to comment Share on other sites More sharing options...
tater Posted July 11, 2022 Share Posted July 11, 2022 Max q MECO, stage sep, SES-1, fairings Nominal Entry burn S1 LOS (boo) Landing burn landed SECO Quote Link to comment Share on other sites More sharing options...
cubinator Posted July 11, 2022 Share Posted July 11, 2022 A rocket lands itself on a platform on the ocean and no one bats an eye. Quote Link to comment Share on other sites More sharing options...
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