3 ms·

I am going to assume the engines themselves are the most expensive part and would require reconditioning regardless of landings on water or earth, why not just

I am going to assume the engines themselves are the most expensive part and would require reconditioning regardless of landings on water or earth, why not just make that part recoverable? Parachute it back? Can the method used by Scaled Composites, jet lifting a rocket to higher altitude, be employed as a better solution? Why not rocket power the plane portion and go for even higher based launch? Granted some cargo would be lost to weight for control surfaces and wings but recovery should be simpler, a glide path cannot be as hard as landing upright.

cecilpl 13y ago
> Why not rocket power the plane portion and go for even higher based launch? That's what the first stage of the Falcon 9 is - a rocket powered boost to enable the second stage to launch from a high altitude.
VLM 13y ago
"why not just make that part recoverable? Parachute it back?" Terminal velocity in atmosphere is proportional to density and engines are surprisingly dense so you'd need to pack a simply enormous parachute. On the other hand, that big mostly empty tank will slow down the engine for you at very little cost, and its nice to reuse it anyway. At the terminal area like 500 feet off the ground you could eject the engines and let the tanks explode but thats messy and bad PR and something you haven't added can't fail, so no parachute means no parachute failures, and you'd already navigated under power to within 500 feet of landing, so its simple, cheaper, more reliable, and much safer to just land under power.
Crito 13y ago
SpaceX has tried to parachute back several first stages, without success. Parachutes for something that heavy and going that fast are very heavy and prone to failure. They also limit you to dropping it in the drink; avoiding that is key to the success of a reusable rocket.

3 ms·

I am going to assume the engines themselves are the most expensive part and would require reconditioning regardless of landings on water or earth, why not just

by Shivetya 13y ago

cecilpl 13y ago
> Why not rocket power the plane portion and go for even higher based launch? That's what the first stage of the Falcon 9 is - a rocket powered boost to enable the second stage to launch from a high altitude.
VLM 13y ago
"why not just make that part recoverable? Parachute it back?" Terminal velocity in atmosphere is proportional to density and engines are surprisingly dense so you'd need to pack a simply enormous parachute. On the other hand, that big mostly empty tank will slow down the engine for you at very little cost, and its nice to reuse it anyway. At the terminal area like 500 feet off the ground you could eject the engines and let the tanks explode but thats messy and bad PR and something you haven't added can't fail, so no parachute means no parachute failures, and you'd already navigated under power to within 500 feet of landing, so its simple, cheaper, more reliable, and much safer to just land under power.
Crito 13y ago
SpaceX has tried to parachute back several first stages, without success. Parachutes for something that heavy and going that fast are very heavy and prone to failure. They also limit you to dropping it in the drink; avoiding that is key to the success of a reusable rocket.