Here's the video. The launcher looks a bit familiar, but I don't think three engines will work, as the centre engine will have too much thrust for landing! A boost-back burn is shown.
Quote from: Steven Pietrobon on 08/20/2022 03:51 amHere's the video. The launcher looks a bit familiar, but I don't think three engines will work, as the centre engine will have too much thrust for landing! A boost-back burn is shown.What is your criteria for "too much thrust for landing"? I am not aware of any theoretical upper limit, higher minimum thrust and acceleration make control more challenging, but not impossible.
Quote from: Barley on 08/20/2022 04:02 pmQuote from: Steven Pietrobon on 08/20/2022 03:51 amHere's the video. The launcher looks a bit familiar, but I don't think three engines will work, as the centre engine will have too much thrust for landing! A boost-back burn is shown.What is your criteria for "too much thrust for landing"? I am not aware of any theoretical upper limit, higher minimum thrust and acceleration make control more challenging, but not impossible.Theoretically, as thrust goes to infinity, the thrust time required to zero the vertical velocity goes to zero. In a real-engine, there's a certain minimal time for startup+thrust+shutdown. Especially a turbopump driven one. Therefore, there is, indeed, a maximal practical landing engine thrust given by the stage dry mass.Besides, given that we are likely looking at a 100t+ launcher, the engine would likely have to be bigger than the F-1.
First, F9 can land using 3 out of 10 engines. In that context landing on 1 out of 3 engines does not seem even slightly extreme.
For the US solar power studies of the 70s wasnt there a huge winged Boeing "Space Freighter" TSTO to launch it ?Answering to myselfBoeing Space FreighterHere we go... 424 t of payload to LEO so with 2 launches a month the ESA requirement is met...
ESA has secured contracts both with ArianeGroup and Rocket Factory Augsburg which will last until September 2023.
Quote from: Barley on 08/22/2022 04:46 pmFirst, F9 can land using 3 out of 10 engines. In that context landing on 1 out of 3 engines does not seem even slightly extreme.Yes, but the three engine burn is only for a short time before switching to a single engine for the actual landing. Even so, this technique is not very reliable and all the recent landings are done with one engine. I believe the reason for not using three engine landings is that the reduced burn time does not give enough time to react to all the random variables during landing (wind speed, acceleration, velocity, position and thrust).