Session
Poster Session II
Event Website
https://www.smallsat.org/index
Abstract
Multi-mode spacecraft propulsion is the use of two or more types of propulsive devices on a spacecraft that share some commonality in terms of either hardware or propellant. An example is the Mars Global Surveyor, which made use of hydrazine as both a monopropellant for attitude control and a bipropellant for primary maneuvering. Specific to this study is a multi-mode propulsion system making use of a high-thrust chemical mode and a high-specific impulse electric mode. Using these two modes can be beneficial in two primary ways. One way is by designing a mission such that the high-thrust and high-specific impulse maneuvers are conducted in such a way that it provides a more optimum trajectory over a single chemical or single electric maneuver. The second is to increase the mission flexibility of a single spacecraft architecture in that both high-thrust and high-specific impulse maneuvers are available to mission designers at will, perhaps even allowing for drastic changes in the mission plan while on-orbit or with a relatively short turnaround from concept to launch. For the second method, it is extremely beneficial to utilize a shared propellant for both modes as this provides the highest flexibility in terms of mission design choices. 9 Previous research has investigated a multi-mode system utilizing a single ionic liquid propellant for chemical monopropellant and electrospray modes. Two propellants were developed that may not only function, but theoretically perform well in both modes. These propellants, based on binary mixtures of ionic liquid fuels [Emim][EtSO4] and [Bmim][NO3] with ionic liquid oxidizer hydroxylammonium nitrate (HAN), have been previously synthesized and tested for thermal and catalytic decomposition in a microreactor and electrosprayed in a capillary emitter.
This paper will present the design of a multi-mode micropropulsion system for nano- and picosatellites. The system uses a shared propellant, as described above, and shared hardware including tanks, feed lines, valves, and thruster to provide both monopropellant and electrospray propulsive capabilities. The thruster is a catalytic microtube integrated with a capillary electrospray emitter. Using experimental results investigating operation of each mode separately, power, mass, and flow control requirements are developed and scale favorably for small satellite systems. For a 6U cubesat, the system has a three times larger mission design space compared to a system using completely separate, state-of-the-art monopropellant and electrospray thrusters. The effect of using a fully integrated thruster is shown to increase delta-V capability at a given mission duration time by 40% compared to using separate, state-of-the-art thrusters. The final paper will include potential mission applications of the final propulsion system design for a cubesat system.
Included in
Design and Development of a Multi-Mode Monopropellant Electrospray Mircropropulsion System
Multi-mode spacecraft propulsion is the use of two or more types of propulsive devices on a spacecraft that share some commonality in terms of either hardware or propellant. An example is the Mars Global Surveyor, which made use of hydrazine as both a monopropellant for attitude control and a bipropellant for primary maneuvering. Specific to this study is a multi-mode propulsion system making use of a high-thrust chemical mode and a high-specific impulse electric mode. Using these two modes can be beneficial in two primary ways. One way is by designing a mission such that the high-thrust and high-specific impulse maneuvers are conducted in such a way that it provides a more optimum trajectory over a single chemical or single electric maneuver. The second is to increase the mission flexibility of a single spacecraft architecture in that both high-thrust and high-specific impulse maneuvers are available to mission designers at will, perhaps even allowing for drastic changes in the mission plan while on-orbit or with a relatively short turnaround from concept to launch. For the second method, it is extremely beneficial to utilize a shared propellant for both modes as this provides the highest flexibility in terms of mission design choices. 9 Previous research has investigated a multi-mode system utilizing a single ionic liquid propellant for chemical monopropellant and electrospray modes. Two propellants were developed that may not only function, but theoretically perform well in both modes. These propellants, based on binary mixtures of ionic liquid fuels [Emim][EtSO4] and [Bmim][NO3] with ionic liquid oxidizer hydroxylammonium nitrate (HAN), have been previously synthesized and tested for thermal and catalytic decomposition in a microreactor and electrosprayed in a capillary emitter.
This paper will present the design of a multi-mode micropropulsion system for nano- and picosatellites. The system uses a shared propellant, as described above, and shared hardware including tanks, feed lines, valves, and thruster to provide both monopropellant and electrospray propulsive capabilities. The thruster is a catalytic microtube integrated with a capillary electrospray emitter. Using experimental results investigating operation of each mode separately, power, mass, and flow control requirements are developed and scale favorably for small satellite systems. For a 6U cubesat, the system has a three times larger mission design space compared to a system using completely separate, state-of-the-art monopropellant and electrospray thrusters. The effect of using a fully integrated thruster is shown to increase delta-V capability at a given mission duration time by 40% compared to using separate, state-of-the-art thrusters. The final paper will include potential mission applications of the final propulsion system design for a cubesat system.
https://digitalcommons.usu.edu/smallsat/2016/Poster2/17
