4 ms·

Yeah, what's up with that?

• userbinator 11y ago
  Things that need to stay very secure, but also quickly detach when needed, are usually attached with explosive bolts. Much simpler and far more reliable than other means.
  • 4ad 11y ago
    But why do they need to detach at all?
    • userbinator 11y ago
      They protect the antennae during re-entry, otherwise they'd probably melt in the heat. If you read carefully you'll see that it's the antenna covers that explode, not necessarily the antennae themselves.
      • CWuestefeld 11y ago
        Yes, but why? Why not just leave them attached there?
        • Keyframe 11y ago
          They probably don't function as well (at all) with covers on.
        • fluxquanta 11y ago
          A basic quarter wave VHF antenna is about a foot and a half long (assuming this is the type of antenna used). A foot and a half long piece of wire can't be hanging off of a capsule coming through the atmosphere without burning off, as others have stated. It would need to be protected for re-entry. When it comes time to use it after the capsule lands, it can't be enclosed within a metal capsule which would undoubtedly act as a Faraday shield preventing the RF from getting outside. So the protection has to come off.
        • sandworm101 11y ago
          They don't want them to stay closed should they be covered by a tree branch or clump of Siberian mud. The explosive opening breaks metal bolt holding the plate on, bolts strong enough to prevent any accidental opening during landing/crashing. And, no explosives means no moving parts to get stuck.
      • 4ad 11y ago
        > it's the antenna covers that explode, not necessarily the antennae themselves. Ah, yes, that explains it. Thanks for the observation.