Multi‐Scale Investigation of a Colloid Micro‐Propulsion System

Abstract

IntroductionElectric propulsion is an advanced form of spacecraft propulsion which has many advantages over traditional counterparts. This propulsion device can be useful for satellites for the purpose of station-keeping, attitude control and possibly de-orbiting at end-of-life to reduce space debris. Advanced electric propulsion has also been demonstrated to be highly efficient for both commercial and military satellites. Indeed, electrostatic propulsion exhibits high specific impulse. i.e., exhaust velocity is very high. The thrust is relatively small but the combined effect of an electric propulsion system leads to significant reductions in propellant usage and enhanced lifetime. To illustrate, a relatively small force kept constant for a long period of time produces a relatively large velocity over time. The Tsiolkovsky equation encapsulates the advantages of electric propulsion: Dv ¼ v e lnðm i =m f Þ; where Dv is the change in velocity of the spacecraft, v e the mass-averaged value of the propellant exhaust velocity and m i and m f are the spacecraft masses before and after the thrusting event, respectively. It is clear from this equation that ambitious missions (i.e., for substantial changes in vehicle velocity), will necessitate a very large initial to final vehicle mass ratio

Recent Advances in MEMS-Based Microthrusters

“…Additionally, the SPM is categorized into vertical structure design and planar structure design according to their structure and the liquid monopropellant microthruster is classified into two types of catalytic decomposition method: Spark ignition and catalytic ignition. Other microthrusters mainly depended on electric 2 of 42 driving including the vaporizing liquid microthruster (VLM) [9,10], plasma microthruster [11][12][13], electrospray microthruster [14][15][16], and colloid microthruster [17][18][19].The free molecule micro-resistojet (FMMR) is also an electrothermal micropropulsion system, which is designed and used for the on-orbit maneuvers of nanosatellites [20,21]. Furthermore, cold gas microthruster (CGM) [22][23][24][25] works by compression and release of high-pressure gas.…”