1. [23-25]
2. As part of the LRR project, the production of fluids (liquids and gases) from the waste materials aboard a space vehicle may be many and varied. These fluids can be used in a propulsion option called the resistojet. The resistojet is a form of electric propulsion known as an electrothermal thruster, where power is provided to the thruster to vaporize and heat the propellant to high temperature, and then the hot gas is passed through a converging-diverging deLaval nozzle, expanding the gas to supersonic velocities.31-37The heating of the fluid provides much higher exhaust velocity (or specific impulse) than if the fluid were used in the cold gas mode without heating. The resistojet can accommodate many different fluids. 1. 1970s resistojet research
3. The Space Station Biowaste Resistojet Propulsion system was required to operate automatically, with little or no crew participation except for maintenance and repair, etc. Thus, system control was required to acquire stabilization and attitude control (S&AC) data, calculate impulse requirements, determine propellant utilization and provide the necessary operating commands; typically once per orbit. Furthermore, the interface with the ECLSS (propellant supply) and the high duty cycle and usage (25 to 80 percent each orbit) makes operational control significantly different and more complex than conventional systems.312. 1980s resistojet research