An adorable lil' antenna that looks like it's been lifted straight out of Star Wars.
Nothing as diminutive as the Mars satellite—which belongs to a class called CubeSats—had ever gone farther than low Earth orbit. The antenna would be stowed during launch, occupying only about 830 cubic centimeters. Shortly thereafter, it would unfurl to a size three times as large as the satellite itself. It would have to survive the 160-million-kilometer flight to the Red Planet, including the intense vibration of launch and the radiation and extreme temperatures of deep space.
As its name suggests, RainCube is built to watch the weather. Its radar will help NASA study precipitation and improve weather-forecasting models. NASA scientists are planning to launch a constellation of such satellites to achieve better temporal resolution than a single large satellite can provide. This tiny radar craft is only about the size of a cereal box (“6U” in CubeSat parlance). The power system, the computer, the control system, and everything else must fit into that box.
The satellite will send and receive radar signals through a parabolic antenna. The main dish will reflect the signals onto a device called a subreflector, which will channel them into a “feedhorn” and from there into the satellite’s radar circuitry. Prior to being deployed, however, that antenna needs to fold up into a canister measuring 10 by 10 by 15 cm. And the 35.75-gigahertz frequency at which the radar operates means that the reflector must deploy so precisely that its shape deviates from perfection by no more than 200 micrometers.
After some intense brainstorming, the RainCube antenna team settled on an antenna that works a bit like an umbrella stuffed into a jack-in-the-box. This approach was the simplest solution, given the volume available. When an umbrella opens, the ribs extend outward and stretch the fabric until it’s taut. RainCube’s antenna works the same way: During deployment, a series of ribs pull the antenna into the right shape to transmit and receive signals.
https://spectrum.ieee.org/aerospace/satellites/new-antennas-will-take-cubesats-to-mars-and-beyond
I've become a supporter of the iterative process of space exploration. Where we try new things over and over, making small improvements with each test. Pushing the limits.
ReplyDeleteThe transition between the flights from Mercury to Gemini to Apollo show this.
But since then, we've sort have been stuck. Sure we push out, but usually with one time unique builds rather than iterative builds.
What I just realized with this mission is the CubeSats have done just that. We went from short flights from low Earth launches to more flights with better tech, to longer flights, and, now that we reached a critical development point, have pushed to interplanetary CubeSats.
And this mission could be seen as the first iterative step towards building a transmission interplanetary infrastructure. Where we put one expensive general receiver/transmitter in orbit around a world, and tons of cheap, specialized CubeSats in orbit using the transmitter as a communications hub to save weight and power.