The sodium-sulfur battery is emerging as a prime high-temperature energy storage technology for space flight applications. Useable specific energy of two to three times that of Ni-H2 batteries is the key advantage of Na-S. This represents a significant launch cost savings, and increased payload mass capability. A Na-S cell demonstration is planned for a 1995 NASA Space Shuttle flight which focuses on the micro-gravity effects on individual cells. This paper will describe the experiment plan in detail.