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Question: Why don't they land into the water instead of a hard surface? (Wouldn't this give them more leeway in terms of impulse?) Edit: i.e. landing on a net
by hurin 12y ago
Question: Why don't they land into the water instead of a hard surface? (Wouldn't this give them more leeway in terms of impulse?)
Edit: i.e. landing on a net stretched (under the lake/ocean-surface) by 3 or 4 ships - reel the net it in to raise stage out of the water, I'm pretty sure seawater is not significantly corrosive from 2-3 hours of exposure.
- hydrogen18 12y agoThis how NASA recovered the SRBs. They landed upright, much like SpaceX's rocket. They were bouyant and floated vertically. The tender would approach the SRB, hook onto it, pump more water into it so it would sink. It would then carry it horizontally back to land. Seawater is incredibly corrosive and as it evaporates it leaves behind a fine layer of sea salt. Since these were SRBs, they had few moving parts. They were completely disassembled and the individual components were inspected and recertified prior to the next launch. Also, just to give you some scale of how crazy the Space Shuttle program was: the SRBs are the largest lift platform that was ever in use. ICBMs are fireworks compared to them. To land in the water, the SRBs needed not one but 3 of the largest parachutes ever produced.
- TeMPOraL 12y agoCorrect me if I'm wrong, but AFAIR SRBs weren't really reused, it was cheaper to make new ones than refurbish those they fished out.
- hydrogen18 12y agohttps://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster#Descent_and_recovery https://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Boo... Some of the parts from the first missions were re used on the last. The SRBs weren't disposable, but they were essentially refurbished after each launch.
- rdoherty 12y agoThey have landed it in the water once as a proof of concept. Seawater is very corrosive and would require cleaning & inspection of nearly all the components. Landing on a dry surface means they can eventually reuse rockets soon after landing (a few days I believe).
- elif 12y agosame reason they don't land planes in water. it would damage the plane, and then you'd have to get it out of the water somehow.
- olex 12y agoCurrently they land on an autonomous ship (huge flat barge with stationkeeping engines and autonomous control). Reason is, they haven't yet proven that their approach and landing are accurate enough to get permission to try a landing on land. If the rocket misses the ship, it goes for a swim and damages nothing except itself. It it goes out of control during approach over land, there's much more damage it can do to all kinds of things. Also, there's no land downrange from the launch site, and returning the stage to land at the launch site costs a lot of extra fuel. It is possible and actually planned to do so later (SpaceX is constructing a landing pad for this purpose at the Cape at this time), but for now they are trying to get the ship landings down properly.
- ZoFreX 12y agoThe eventual goal is to land it on land, they're only doing water landings right now due to the high chance of failure. In the future, the first stage will land back at the rocket pad, which massively reduces the logistics for re-using it. There's a cool mock-up video of what that might look like: https://www.youtube.com/watch?v=4Ca6x4QbpoM https://www.youtube.com/watch?v=4Ca6x4QbpoM
- hurin 12y agoSo you're saying the real cost-savings don't kick in until you're landing it back on the pad, hence salvage from sea is only important as far as perfecting the technology?
- benihana 12y agoYep. They're doing it at sea because they're in the late alpha stage of this reusable program.
- pbreit 12y agoSorry, but I'm failing to see how sending a large barge out into the ocean constitutes "massive logistics".