PRELIMINARY MODELING AND VERIFICATION OF DRAGRACER RIBBON TETHER PERFORMANCE FOR DEORBITING APPLICATIONS

The ribbon tether for the DRAGRACER deorbiting experiment is designed to increase the effective cross section of a satellite, producing additional aero drag, and thus reducing deorbit time. This recent experiment involved two identical spacecraft, ALCHEMY and AUGURY, excepting ALCHEMY deployed a 70m deorbit tether, thus allowing a direct side by side orbital drag comparison. As deployed, the ALCHEMY’s flat ribbon tether is approximated using small, adjoined elements using a six degree of freedom multibody model, where each element of the modeled tether stays connected to its adjacent elements while experiencing aerodynamic lift and drag along with restoration torques. Modeling techniques are derived, including the effects of torsional restoration and aerodynamic forces. Mass and physical properties of the DRAGRACER satellite/tether system are adopted and then simulated to compare with observations of the actual drag experienced by the spacecraft. Motion of the tether itself is characterized, exhibiting a range of surprisingly active and chaotic dynamics.