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Makes me wonder if a giant, clear beach ball could be converted into a parabolic dish simply by spraying a ferrous-based paint on a section/hemisphere of it (wi
by mikece 3y ago
Makes me wonder if a giant, clear beach ball could be converted into a parabolic dish simply by spraying a ferrous-based paint on a section/hemisphere of it (with the receiver injected via the inflation tube).
(They didn't specify how 1/3 of the balloon's surface was "alluminized"... spraying would be a pretty easy way to do it, if it worked.)
- mikewarot 3y agoFirst you have to cut it in half, and add the metalized interior partition that becomes the parabola. Then plastic weld all the seams, putting it back together into a bisected sphere. If you pressurize both halves correctly, with the right differential, Bob's your uncle. If you have the means to weld seams in Mylar, it would likely be easier to build one from scratch.
- pokey00 3y agoWhy cut it in half? Spray (or Mylar) on the outside.
- wtallis 3y agoA parabola isn't the same shape as a hemisphere. (Although, I'm not convinced the antenna under discussion actually is a parabola and not a catenary, or something in between.)
- djcannabiz 3y agoSome other comments posted a diagram-the actual reflector is inside the balloon. the balloon is there to keep the reflector in the right shape.
- wrigby 3y agoObligatory GATR link: https://www.cubic.com/inflatable-satellite-antenna# https://www.cubic.com/inflatable-satellite-antenna# These are used in disaster response and other scenarios that demand rapid deployment of satellite terminals.
- thebiss 3y agoDoes this mean there is already a commercial version? If so, what is the advantage of the NASA funded project?
- gorkish 3y agoGATR works on the ground in atmosphere. Having seen them up close, I don't think there is a lot that translates to an in-space application other than the concept itself. You're talking about a completely separate ground-up engineering effort.
- Animats 3y agoMore hype for NASA. Congress should cut NASA's PR budget.
- gorkish 3y agoI have spoken with the guy behind cubic/GATR (actually had a conversation with him and Buzz Aldrin at Space Symposium quite some years ago.) It's surely the first thing that came to my mind, and a fairly mature technology at this point in use by lots of people in the field. I came to the comments specifically to note this system, and thankfully found your reference. I have wanted to try to DIY one for a moonbounce station ever since.