NASA to build 3D printed telescope

The telescope is being fabricated using an additive manufacturing process whereby the structure is built up layer-by-layer, by fusing a metal powder using a computer-controlled laser beam as indicated by a 3D CAD model. As each layer is created, more powder is laid down and the process is repeated. The excess powder is then removed and the component can be polished. NASA says the process allows for very fast prototyping and reduces fabrication costs. Because it can create very complex structures, the number of components needed is also greatly reduced. Budinoff's current design is a 50mm camera small enough to fit in a CubeSat, a tiny satellite comprised of individual units about 4in in size. The telescope has only four 3D printed parts, compared to traditional designs which have about 40. Budinoff is also working on a 350mm dual-channel telescope which he says is more representative of a typical space telescope. Both are being developed to show that telescope and instrument structures can benefit from advances in 3D printing. "The goal isn't to fly them, at least not yet," he stressed. "This is a pathfinder. When we build telescopes for science instruments, it usually involves hundreds of pieces. These components are complex and very expensive to build. But with 3D printing, we can reduce the overall number of parts and make them with nearly arbitrary geometries. We're not limited by traditional mill and lathe fabrication operations." Budinoff expects the camera assembly to take just three months from start to finish. His next goal is to see if powered aluminium can be used to produce 3D printed telescope mirrors – a challenge considering how porous the material is. The plan is to use a process called hot isostatic pressing to squeeze a thin layer of aluminum in a pressure chamber using an inert gas at 15,000psi to a suitable density. "We think this, combined with the deposition of a thin layer of aluminium on the surface and Goddard-developed aluminum stabilising heat treatments, will enable 3D printed metal mirrors," Budinoff noted. "Anyone who builds optical instruments will benefit from what we're learning here. I think we can demonstrate an order-of-magnitude reduction in cost and time with 3D printing."