Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

Appendix L: Tether Boost Facility Design Final Report5.3 Sub-Scale Electrodynamic Tether Boost Facility DemonstrationA sub-scale flight experiment is needed to demonstrate the MMOSTT uniqueconcepts. Demonstrations would include spin-up of the tether boost facility, deploy ofthe ED tether during spin-up, release of a payload, capture of a different payload (e.g.,microsat), and reboost of the tether boost facility.5.3.1 ConceptA maximum mission cost of $50M, not including launch vehicle costs, wasassumed. The depleted launch vehicle upper stage would be used for the ControlStation. In additional to providing the needed mass, the upper stage would provide alsothe avionics and attitude control system for the Control Station, thus reducing costs.The launch vehicle payload would consist of the tether, the tether deployer, amaneuverable Grapple Assembly (with a simple, deployable-only payload attached),solar arrays, and a second, maneuverable, deployable/retrievable payload (e.g., amicrosat). Having a low-cost, deployable-only payload attached to the grapple atlaunch allows the experiment to verify the payload release mechanism and releaseprecision even if the second payload cannot be captured due to a malfunction.The first part of the mission would consist of launching into LEO, deploying themicrosat, firing the upper stage to place the Control Station in the required orbit,spinning-up the Control Station while deploying the tether, stabilizing this demonstrationtether boost facility, and then releasing the simple payload. The second part wouldconsist of the microsat adjusting its orbit for rendezvous with the rotating tether boostfacility, approaching the tether Grapple Assembly, being captured by the maneuverablegrapple mechanism, and then being released to a higher orbit, one-half rotation later.The third part of the mission would consist of demonstrating various orbit maneuvers ofthe tether boost facility, evaluating tether survivability and motion predictability oversome desired duration, and eventually ending the mission with a tether-powereddeorbit.5.3.2 DesignTo further reduce cost, the maneuverableGrapple Assembly and target payload could be apreviously-designed microsat, such as an XSS-10(see graphic right). An XSS-10 or similar vehicle iscapable of rapid movement and is already spacequalified.Two such units would be used, with additionalgrapple fixtures added on the unit destined to be theGrapple Assembly, and the mating half on thevehicle used as the target payload. If a Delta IIupper (second) stage is used, with a dry weight of950 kg (see Figure 5.6), a 10-kilometer ED tetherF-32