A report proposes the development of modular propulsion clusters (MPCs) — small, self-contained propulsion systems that would be standardized, mass-produced, and readily installed on a variety of miniature future spacecraft. The MPCs would be inexpensive, "turn-key" alternatives to expensive conventional propulsion systems that are designed and built integrally with other spacecraft systems and structures. Each MPC would contain its own propellant tank, isolation valve, gas plenum, and valve/nozzle thruster assemblies. Each MPC would be delivered fully loaded; installation on a spacecraft would involve only mounting and electrical connections. The propellant would be a liquid that, by electrical actuation of valves, would be metered into the plenum as needed to vaporize and generate thrust. An important advantage of using a vaporizing propellant liquid (as opposed to a propellant gas) is that stopping a liquid leak is orders of magnitude easier than is preventing a gas leak.
This work was done by Barry Nakazono of Caltech for NASA's Jet Propulsion Laboratory. To obtain a copy of the report, "Modular Propulsion Cluster," access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Machinery/Automation category.