Deployable structures for antennas

So yes, what am I doing exactly? “Deployable structures for antennas” – what is it? And why does it have to be “deployable”?

When a telecommunication satellite is launched, it’s main goal is to talk with the Earth, to listen on one side, and to repeat the message on the other side. It works a bit like a phone in a way: it allows two people, two computers or two machines to discuss. But a satellite can be very, very far from the Earth, so how can he listen, or talk, to you? He needs really big ears, and a really big megaphone. Ok, the comparison stops there, because it’s not sound but radio waves that are used, and it doesn’t really have ears nor a mouth. But it does have big, sometimes very big antennas.

How big? you see the smallsatellite antenna dish on the roof antennas on the side or the roof of some building, pointing at the sky? Those are actually used to “listen” to TV satellites that broadcats all kind of channels. And they are probably about 50cm in diameter. Well, it is pretty common for satellite antennas to measure 2 or 3 m in diameter! And some are even much bigger: the largest antenna flying measures close to 20m in diameter – that’s a 6 floors building!

80sqvsgfkmEvftZuFcRJwQqiegCe-ORHEnWsmWyy8lcSo now that we have those big antennas (and I have only mentioned telecommunication, but they can also be used for earth or space observation, radars, etc…), how do we launch them? See, the problem is that you cannot put this 20m antenna in a rocket, it would not fit. The last stage of the rocket, where the satellite is, has a diameter of 4m for the biggest rockets. Because of that, even for a “small” 4m diameter antenna, there is only one solution: you have to fold it, and once up there, open it up. There is something really similar that is used really often here, on earth. It can be very small, fit in your bag, but when it rains it get big enough to keep you dry: that’s right, I’m building a giant umbrella, for a satellite.

Does it look like an umbrella? Hmm, not really, but the idea is there. How do you do it then? Well, that’s the whole point of my thesis! I wouldn’t spoil it all and tell you now, right? But as a trailer I can show you what Large Space Structures GmbH, a partner of the REVOLVE project, has been doing recently.

Banner image and video : courtesy of LSS GmbH.
Ariane 5: ESA-CNES-ARIANESPACE-Photo Optique Video CSG