Last year SEDS-1 demonstrated that a tether could sling a payload into a controlled reentry trajectory. The innovation proposed here is to integrate a tether deorbit operation into the design of a small general-purpose reentry capsule. This can reduce simultaneously the capsule complexity, cost, hazards, and reentry errors, hence making SEDS a clearly useful element of space infrastructure. Our objective in Phase I is to determine the feasibility and refine the design enough to commit to fabricating a flight capsule in Phase II. The Phase I effort includes simulation and analysis of capsule deboost, reentry, and recovery; development of hardware and software requirements; selection of components; design of the capsule structure, and fabrication of a full-size model. We anticipate fabricating in Phase II a 60 kg flight capsule suitable for launch as a Delta secondary payload, a Pegasus coprimary, or a Cosmos or shuttle Hitchhiker. NASA applications and benefits include collecting transition and continuum aeroheating data to validate CFD codes, verifying the flight performance of new TPS materials, and (with some component changes) returning time-critical samples from long-duration shuttle missions and from the space station. CFD validation, flight testing of new TPS materials, and return of samples from the shuttle and space station all have value to industry as well as to NASA. More important may be the enabling factor provided by a very affordable "down-link" for commercial activities. This capsule is light enough that the tether-induced disturbance to the space station is only 1E-5 gee, and multiple capsules can be stored nested in a small volume. Hence it may be affordable to use such capsules as often as weekly. This could have a significant impact on commercial activity levels on extended-duration shuttle missions and on the space station.
Keywords: Phase_I, NASA, Abstract, FY94
