In-Space Propulsion

Abstract : As the world of flight enters its second century, in-space propulsion nears the end of its first 50 years. The field is progressing rapidly, with a diversification of propulsion technologies that enable space missions that were previously untenable. This paper will summarize the state of the art and current development efforts for the major classes of spacecraft propulsion: chemical, electric, and solar thermal. Chemical propulsion systems remain the backbone of spacecraft architectures. Work continues to improve the performance, storability, and environmental friendliness of liquid monopropellant, bipropellant, cold gas, and gel systems for orbital insertion, stationkeeping, orbital maneuvering, and attitude control. Electric propulsion, once the "technology of tomorrow" has entered the mainstream of in-space propulsion, establishing operability for stationkeeping and orbital insertion and being baselined for next generation scientific deep space and interferometry missions. Research efforts are now concentrated primarily on expanding the applicable power range for electric propulsion systems in order to enable large orbit transfer vehicle applications and micro/nano spacecraft propulsion systems. Solar thermal propulsion is also discussed. A comprehensive research and development effort is ongoing in the United States and Europe in industrial, academic, and national laboratory settings to advance the state of the art for spacecraft propulsion systems. Apart from technological developments in these various fields, the economic pressure on both commercial and scientific missions is increasing and customers require an industrialization of space businesses. Improvements in these areas have been achieved within the Astrium EUROSTAR and Alcatel SPACEBUS series.