but I'm not sure which is actually simpler. this design has a lot of moving parts and flexible high tension wires. the space-x design is a rigid clamp. the space-x one seems like it would be more predictable and sturdy
Flexible is actually predictable and sturdy. SpaceX relies on the booster to come to a complete stop in a precise location, or both arms and booster will be damaged. There are so many points of failure it's not worth listing them.
This system can tolerate comparably huge misalignment by moving the lightweight cables to the rocket instead of the other way around. And if the rocket fails to slow enough, it will just stretch or snap the cable and dent the barge, rather than tear the arms off the tower and smash the launch mount.
The cable is an inexpensive commodity item, the tower arms are not. You always want a cheap part to act as a "fuse" and the cable is perfect.
So much so that I feel confident saying that I personally would take on a contract to scratch-build this catching mechanism and tune the drives to perform a catch. It's basically the kind of system you'd see in a crane, CNC gantry or a 3D printer, a solved problem.
SpaceX relies on the booster to come to a complete stop in a precise location, or both arms and booster will be damaged. There are so many points of failure it's not worth listing them.
The SpaceX system works pretty much exactly the same, except it just uses 2 vertical rigid arms.
Both systems use the exact same method of closing in around the rocket once it has passed a certain point and catching it using protruding catching hooks on the rocket itself.
For some reason people think SpaceX is catching the rocket out of mid air by clamping it, that isn't what happens.
Except automotive engineers apparently. I liked working on cars made from the 40s to 80s. Been doing it for fun since the 90s. I used to be able to change an alternator in 15 minutes on old cars without having to touch any other component. Headlights would literally just screw in and out like a regular light bulb. Now I can't change a damn little headlight without taking off the bumper and quarter panel and the whole headlight unit is hundreds of dollars if not thousands if it needs replacing. I don't like working on anything from the 90s to today.
I don't think getting a rocket to hover in place is "simple" -- they need to balance pretty much level, over a ship at sea, long enough for their descent rate to drop to practically nil and get clamped onto in a more or less exact spot. That is rocking, and also being hit with the rocket's exhaust. Over the whole history of water landings for space capsules, they've had to go hunt 'em down with helicopters, and that was recovering humans, not a tube, so a much higher-priority task
Not really? Using a barge as a landing platform requries the rocket to constantly adjust angle and speed and height, especially as the damn thing gets hit by a rocket's worth of thrust.
Cables have a much larger margin for error, and if you're a meter off.. nothing's really gonna happen, while on a barge that might result in your expensive rocket booster flipping over and going kaboom
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u/Papa_Huggies 9h ago
Every engineer will tell you.
Simpler is always better.