Monday, January 18, 2016

Space is Hard

Falcon 9 almost stuck the landing.

Back in the day, when SF movies always showed rockets landing tail-first, none of them blew up. Of course, they weren't landing on barges, either.

9 comments:

  1. I don't get Musk's fixation about landing at sea... anyone got a guess why?

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  2. In the 50s movie "It! The Terror from Beyond Space," the first rocket ship to Mars toppled and "cracked up on landing." The opening shot shows the broken wreckage, then pans over to the rescue ship standing nearby. A lot of the 50s magazine and book covers showed ships blowing up exactly that way.

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  3. Depending on the launch parameters, there might not be sufficient energy to fly the booster back to the launch point. Also, in case of failure, there's no hazard to people. They might not have had a landing site to use. Or maybe they couldn't get whatever permits were required.

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  4. Leo: It allows them to carry more payload. If they want to return to the launch point, the rocket must make a U-turn. To reverse the course of that much mass requires a lot of fuel, which cuts into the payload limit. However, if they have a barge on its original trajectory, the rocket will fly its normal parabolic arc and will only need to carry as much fuel is required to stick the landing.

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  5. And I'm sorry... I meant Hans, not Leo.

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  6. Mark: What U-turn? It's just a matter of waiting through one or more orbits. Once you've achieved orbit, you can reach any point at a latitude not more than the launch point with a minor energy expenditure.

    And no way is the trajectory parabolic: it's an ellipse.

    Like eb says, ocean retrieval is just the cheapest route to not endangering people.

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  7. Deadstick, the first stages don't make it to orbit. As best as I can determine, MECO and then state separation occurs at roughly 50 miles AGL. Which is well below orbital altitudes.

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  8. THANKS ALL... it's a bastard of a problem though, all that bobbing about, unpredictable swells and all

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  9. An inherent problem with using this system is that it requires good sea and/or weather conditions at the landing zone when the rocket is launched. It just adds another variable to the launch criteria, as if there weren't enough already.

    Actually, there is another variable, ie: if there is traffic near the barge location. I would hope there is a self-destruct system, for the potential problem of the rocket not being able to maneuver correctly between separation and arriving at the landing zone.

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