SoylentNews is people
SoylentNews
NASA's James Webb Space Telescope has a giant custom-built, kite-shaped sunshield driven by mechanics that will fold and unfold with a harmonious synchronicity 1 million miles from Earth.
[...]
The sunshield support structure contains well over 7,000 flight parts, including springs, bearings, pulleys, magnets, etc. In addition, the sunshield has hundreds of custom fabricated pieces. Most mechanical pieces were developed exclusively for the sunshield, with a few from existing designs.There are about 150 mechanism assemblies that have to function properly to fully deploy the sunshield. Within those mechanism assemblies, there are numerous small parts that work in harmony. The smaller parts include about 140 release actuators, approximately 70 hinge assemblies, eight deployment motors, scores of bearings, springs and gears, about 400 pulleys and 90 cables. These mechanisms release the sunshield membranes from their folded and stowed launch configuration, deploy the supporting structures, and unfold and tension the membrane layers. In addition there are hundreds of magnets and clips to manage the membrane shape and volume during deployment, and many sensors to tell engineers that each deployment step has been completed.
"The process of opening or deploying the sunshield in space is a multi-step process," said James Cooper, Webb telescope sunshield manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
[...] "There has never been a composite structure this large and complex (for a NASA mission)," Cooper said.
(Score: 0) by Anonymous Coward on Tuesday September 27 2016, @09:04PM
For some reason they need 5 layers of what looks like aluminum coated Mylar, so even if you work out a simple design, it still needs to be 5 layers thick. And it is pretty big to shield the whole telescope.
From tfa:
> .........
> Each step of the deployment will be manually initiated from engineers on Earth. That sequence runs automatically to its completion (with automated stoppage in case of a fault), then the system waits for the next command.
> ...
> The mechanisms that separate each of the sunshield's five layers do so with precision. Near the center of the sunshield each layer is separated by only a couple inches, but the layer-to-layer gap increases as you move away from the center, to about a foot between layers around the edges. It will take nearly two days to fully deploy the sunshield system when in orbit.
> ...
> ...about the size of a tennis court (about 21 meters by 14.5 meters, or 68.9 feet by 47.5 feet).