Solid Surface Combustion Experiment Completes a Series of Eight Successful Flights

In the first five flights, the fuel sample--ashless filter paper instrumented with three thermocouples--was mounted in a sealed chamber filled with a 50-percent or 35-percent mixture of oxygen in nitrogen at pressures of 1.0, 1.5, and 2.0 atm. In the next three flights, a polymethyl methacrylate (plexiglass) fuel was instrumented with three thermocouples and tested in a 70-percent or 50-percent mixture of oxygen and nitrogen at pressures of 1.0 and 2.0 atm. SSCE is a self-contained, battery-operated experiment that can be flown either in the shuttle middeck or in the Spacelab module. Reference 1 provides more information about the hardware configuration.

This past year, the final two of eight flights were completed on STS-64 and STS-63. The NASA Lewis Research Center designed and built the SSCE payload and performed engineering, testing, scientific, and flight operations support. The SSCE project was supported in some way by nearly every major sector of Lewis' organization.

Professor Altenkirch developed a numerical simulation of the flame-spreading process from first principles (of fluid mechanics, heat transfer, and reaction kinetics). The spread rates, flame shape, and thermodynamic data from the SSCE flights are being compared directly with the results of the computational model. Results from the eight flights will be used to formulate an improved solid-phase pyrolysis model. In addition, some results of the flights have been published (ref. 2) and presented at international combustion symposiums. Additional solid fuel combustion experiments are being investigated for future tests with the existing hardware.

References

1. Vento, D.M., et al.: The Solid Surface Combustion Space Shuttle Experiment Hardware Description and Ground-Based Test Results. AIAA Paper 89-0503, 1989.

2. Bhattacharjee, S.; Altenkirch, R.A.; Sacksteder, K.R.: Implications of Spread Rate and Temperature Measurements in Flame Spread Over a Thin Fuel in a Quiescent, Microgravity Space-Based Environment. Combust. Sci. Tech., vol. 91, 1993, pp. 225-242.