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Chang, Rebecca

Publications and source records attributed to Chang, Rebecca.

Sodium-sulfur battery flight experiment definition study

Sodium-sulfur batteries are considered to be one of the most likely battery systems for space applications. Compared with the Ni-H2 or Ni-Co battery systems, Na-S batteries offer a mass reduction by a factor of 2 to 4, representing significant launch cost savings or increased payload mass capabilities. The Na-S battery operates at between 300 and 400 C, using liquid sodium and sulfur/polysulfide electrodes and solid ceramic electrolyte; the transport of the electrode materials to the surface of the electrolyte is through wicking/capillary forces. This paper describes five tests identified for the Na-S battery flight experiment definition study, which include the cell characterization test, the reactant distribution test, the current/temperature distribution test, the freeze/thaw test, and the multicell LEO test. A schematic diagram of Na-S cell is included.

Chang, Rebecca↗

Sodium-sulfur battery flight experiment definition study

NaS batteries have been identified as the most likely successor to space Ni-H2 or Ni-Cd batteries, primarily due to a mass reduction by a factor 2 to 3 over Ni-H2 and by a factor of 4 over Ni-Cd. This yields major launch cost reductions or payload mass improvements. NaS batteries support NASA OAST's proposed Civil Space Technology Initiative goal of a factor of two improvement in spacecraft 2000 initiative. Since Ni-H2 and Ni-Cd batteries have been space flight proven, it is essential to have the flight experiment to establish a national space technology base to demonstrate the operation of the NaS battery for space applications.

Chang, Rebecca↗