Latest SpaceX Grasshopper hop

First flight of 10 story tall Grasshopper rocket using closed loop thrust vector & throttle control

Video here

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SpaceX: Why use retros on the Grasshopper?
A reasonable question was asked by Oliveri on Reddit  a few days ago

“I have a question for all SpaceX enthusiasts. I want to know why is SpaceX spending so much time and money on re-usable rockets that land on their tail? It looks cool, but that seems to be a lot of weight (fuel and landing gear) and engineering, i.e development costs, to make that happen. Wouldn’t a combination of parachutes and some retro rockets be just as effective and cheaper. Could it be that even parachute landings put such stresses on the structure and/or the inundation of salt water make repairs and inspections just as cost prohibitive as throwing the rockets away in the ocean or burning them in the atmosphere or scrapping and recycling them after recovery?”

The discussion can be found here

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2 Responses to Latest SpaceX Grasshopper hop

  1. sanman says:

    Look, they’ve already tried parachutes, etc, and it doesn’t work. The idea is to have a first stage which can do a boostback to the launch site, while the other higher stages can probably complete a full orbit before returning back.
    Musk has calculated that adding a bit more fuel and some landing legs is lighter than adding parachutes. He’s also pointed out that when you splash down your rockete into the ocean, that salt water damages the rocket and impinges on its reusability.

    • rocketry says:

      Yes as was pointed out in the discussion. I also like the idea of this as practice for Mars. Parachutes are not very effective on Mars so Musk is really tackling two problems here – re-usability and perfecting retro landings which will be needed on Mars.

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