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F9/FH cannot throttle down enough to do a hover landing, so they have to do a suicide burn (i.e., fire the engine just so the speed goes to 0 m/s at 0 m altitude.) The engine is too powerful and the body is too light to hover.

Blue Origin might eventually encounter just that problem with New Glenn.



I don't know where you're getting this idea. The grasshopper hovered all the time in tests and uses the same single-engine as the F9 full thrust.

https://www.google.com/search?q=spacex+grasshopper+video&num...


They probably just put extra weight (fuel) in the grasshopper for easier testing. The F9 on the other hand is basically an empty soda can with engines at the bottom and small fins at the top when it’s landing so even when firing just a single engine at minimum power it will generate too much thrust to hover.


I don't think it was exactly the same engine, and Grasshopper didn't have 9 engines, it had one. The engines are a surprisingly large mass fraction of a dry first stage.




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