Over the past decade, research has been conducted on the technology of Electromagnetic Formation Flight (EMFF), which uses the local generation of electromagnetic fields by the vehicles of a spacecraft cluster to control their relative degrees of freedom without consuming propellant. RINGS, which stands for Resonant Inductive Near-field Generation System, provides a hardware implementation of EMFF that will operate as a payload on SPHERES, the formation flight test facility onboard the International Space Station (ISS). To maximize productivity during the planned ISS test sessions, we will use a parabolic flight campaign to conduct preliminary formation flight testing and begin the control algorithm refinement process.

Problem Statement
Spacecraft formation flight is a potentially enabling technology for any mission where the desired operational size of the structure exceeds the existing launch shroud capacity. This will very likely be the case for future on-orbit telescopes. Examples include the synthesis of very large apertures by a sparse array of smaller apertures, or the assembly of a large segmented aperture from a highly compact stowed configuration, such as might be done for a larger version of the James Webb Space Telescope.

Technology Maturation
The parabolic flight tests of RINGS will act as a bridge between extensive 2D ground testing and long duration 3D testing onboard the ISS, whereby an array of control approaches can be evaluated in a realistic dynamics environment. Any major control implementation issues can be addressed in the intervening periods between flights over the four-day campaign, and the solutions could prevent the loss of valuable testing time on-orbit.

NASA, DoD, NRO, ESA – Benefits any entity utilizing formation flight for on-orbit assembly or aperture synthesis

Future Customers
Propellantless formation flight could benefit or enable any mission where a large degree of reconfiguration is necessary, either during the construction phase of a system that is too large or complex to be deployed from a stowed configuration, or during the operations phase when filling in the u-v plane of sparse aperture. Future space telescopes such as Terrestrial Planet Finder, Stellar Imager and Constellation-X, could have their operational lifetimes greatly extended from this technology.