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Comment by ncmncm | Hacker News Reader

Don't understand why they don't just use an inflatable parachute with a radio beacon antenna sticking out the top. Then they could just drive up anytime and fish it out of the water. Would immersion in salt water for a few hours damage a fairing?

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Salt water is the worst. It takes a lot of effort to clean it all off and it causes corrosion all the while. Even the ones that do hit water, they get them out as fast as they safely can.

As far as I know (correct me if I'm wrong), SpaceX have only reused previously-wet farings on their own Starlink launches. They don't risk potentially damaged parts on external customers.

> Would immersion in salt water for a few hours damage a fairing?

Yes.

They haven't been very public about how much refurbishment is required for fairings that they fish out of the ocean, but they've managed to use them on Starlink launches.

Forget immersion- just contacting salt water is enough to wreck your day. It's highly corrosive and protecting from that corrosion would require engineering coatings that are light, cheap, and also able to handle the temperature and pressure and wind stresses of a literal rocket launch. It's a lot.

Yes. The couple they reused after fishing them out required extensive rebuilds.

There are a lot of electronics on these things and weight is ultimate factor.

Or grab them with a hook dangling from a C-130 like the film from old-timey spy satellites.

Apparently thats been considered, and you still might see another company like electron try it. It's just a bit harder to do safely and some other limitations.

One of the main reasons they aren’t doing it is that the fairing halves are so far out to sea (about 800km down range) that no helicopter could have the range with a fairing dangling down to make it back to land (the Sikorsky Skyhook, for instance, only has a range of 200nmi or so... maybe you could get a specialized helicopter to do it with heroics like drop tanks, but the cost would be much higher), so they’d need to land on a ship after capture anyway. By catching the fairing halves with ships directly, they save the substantial costs of also having helicopters.

Notice that with RocketLab reuse, the helicopter is staged from a ship at sea. However, probably can save more money by recovering a RocketLab Electron first stage than half of a fairing (you’d need one helicopter per fairing halve but only one helicopter for Electron... Electron also has a much smaller and less awkward aerodynamic cross section than a F9 fairing halve). See: https://m.youtube.com/watch?v=enndCzvZpZk

They considered doing that to reuse the Saturn V with a giant helicopter with rockets at the end of each propeller. It didnt go anywhere. Though people have been using air capture for more reasonable use cases, and rocket lab is going to be air capturing their electron rockets.

I haven’t heard about this giant helicopter idea before. Here’s an article I found about it:

https://www.thespacereview.com/article/1045/1

Very cool article. The Hiller Air & Space museum mentioned in the piece is well worth visiting if one happens to be in the Bay Area.

I think you're talking about the old Corona satellites, where they would have film and drop it back to earth: https://en.wikipedia.org/wiki/Corona_(satellite)

The problem with this and a fairing is that if the fairing catches the open side, it's going to drag behind like a giant parachute and take the plane down. The fairing is huge (13m long x 5m diameter), even compared to a big plane.

ULA is planning that (with a helicopter) to catch the engines from their upcoming Vulcan rocket. https://spaceflightnow.com/2015/04/14/ula-chief-explains-reu...

That was the original plan. But according to https://en.wikipedia.org/wiki/Vulcan_Centaur they went ahead without funding it, though they may some time in the future. So for now Vulcan is going to have a disposable first stage, just like all the other old-time space rockets.

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