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Title: Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

Conference ·
OSTI ID:347773
; ;  [1]
  1. Orbital Sciences Corp., Germantown, MD (United States)

This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system efficiencies three to four times as high as present-generation RTGs.

OSTI ID:
347773
Report Number(s):
CONF-970701-; TRN: 99:006227
Resource Relation:
Conference: 32. intersociety energy conversion engineering conference, Honolulu, HI (United States), 27 Jul - 2 Aug 1997; Other Information: PBD: [1997]; Related Information: Is Part Of Proceedings of the thirty-second intersociety energy conversion engineering conference. Volume 1: Aerospace power systems and technologies; PB: 787 p.
Country of Publication:
United States
Language:
English