We’d like someday to be able to have a spacecraft create itself entirely from scratch, but realistically that’s quite a ways out; that’s still science fiction,” says Robert Hoyt, CEO and chief scientist of Tethers Unlimited Inc. Instead, with his “SpiderFab” project, he proposes to use 3D printing technology aboard a tiny CubeSat to create a much larger structure in space.
The project received $100,000 from NASA’s Innovative Advanced Concepts program to hammer out a design and figure out whether spacecraft self-construction makes business sense, Space.com reports. Practical planning and additional funding could lead to the launch of a 3D-printing test mission within several years.
Hoyt explains:
Currently, a significant fraction of the engineering cost and launch mass of space systems is required exclusively to enable the system to survive launch. This is particularly true for systems with physically large components, such as antennas, booms, and panels, which must be designed to stow for launch and then reliably deploy on orbit.
Furthermore, the sizes of apertures and spacecraft structures are limited by the requirement to stow them within available launch fairings. Deployable structures and inflatable/rigidizable components have enabled construction of systems with scales of several dozen meters, but their packing efficiency is not sufficient to enable scaling to the kilometer-size baselines desired for applications such as long-baseline interferometry and sparse aperture sensing.
We propose to develop a process for automated on-orbit construction of very large structures and multifunctional components. The foundation of this process is a novel additive manufacturing technique called “SpiderFab,” which combines the techniques of fused deposition modeling (FDM) with methods derived from automated composite layup to enable rapid construction of very large, very high-strength-per-mass, lattice-like structures combining both compressive and tensile elements.
This technique can integrate both high-strength structural materials and conducting materials to enable construction of multifunctional space system components such as antennas. The SpiderFab technique enables the constituent materials for a space structure to be launched in an extremely compact form, approaching perfect packing efficiencies, and processed on-orbit to form structures optimized for the micro-G space environment, rather than launch environments.
The method can also create structures with 2nd and higher orders of hierarchy, such as a “truss-of-trusses,” achieving 30X mass reductions over the 1st order hierarchy structures used in most space applications. This approach can therefore enable deployment of antenna reflectors, phased array antennas, solar panels, and radiators with characteristic sizes one to two orders of magnitude larger than current state-of-the-art deployable-structure technologies can fit within available launch shrouds.
The SpiderFab process for on-orbit construction of large, lightweight structures will dramatically reduce the launch mass and stowed volume of NASA systems for astronomy, Earth-observation, and other missions requiring large apertures or large baselines, enabling them to be deployed using much smaller, less expensive launch vehicles and thereby reducing total life cycle cost for these missions.