SpiderFab™ is the name of suite of technologies currently being developed by Tethers Unlimited Inc. (TUI), under the auspices of the National Aeronautics and Space Administration (NASA), in the United States. As the name suggests, SpiderFab uses spiderlike robots to fabricate and assemble huge structures in space and is set to revolutionise the way in which spacecraft are deployed.
At present, large spacecraft components, such as antennae and solar panels, are built and tested on the ground before being launched into space aboard a rocket. The total complement of equipment carried by a rocket, known as the payload, is packaged within a â€˜launch shroudâ€™, so the physical size of components is limited by the size of available shrouds.
Furthermore, spacecraft components must survive the launch environment â€“ in which they can experience three times the force of gravity they are exposed to when on Earth â€“ increasing their complexity, mass and cost. Even once in orbit, components are not guaranteed to deploy reliably, as the European Space Agency discovered, to its cost, when attempting to launch its first two â€˜Galileoâ€™ navigation satellites in 2014. In fact, â€˜failure to deployâ€™ has dogged the history of spaceflight.
By contrast, SpiderFab, a demonstration of which could be ready by 2020, would require only raw materials, such as carbon fibre, to be launched into space. Once in orbit, SpiderFab would use 3D printing and robotic fabrication techniques to transform these raw materials into basic structures and assemble them into larger components.
Smaller payloads would mean smaller rockets could be launched, saving money for space agencies. Components built and assembled in orbit would not be beyond the reach of Earthâ€™s gravity but, in terms of structural performance, would be optimised for the space environment.
Indeed, if SpiderFab is successful, it could ultimately build radio antennae, solar arrays and other components to kilometre-scale dimensions. On a smaller scale, NASA scientists want to launch a â€˜starshadeâ€™ â€“ a spacecraft that looks like a giant sunflower â€“ to block excess light and allow planets orbiting stars other than the Sun to be directly imaged by a space telescope. According to Bob Hoyt, CEO of TUI, the â€˜starshadeâ€™ could be built with a maximum diameter of 62 metres (203 feet) on Earth, but twice that diameter if built in orbit, allowing so-called â€˜exoplanetsâ€™ twice as close to their target stars to be imaged.
Image credit: www.tethers.com