MIT Engineers Develop Dual-Mode Propulsion System for Small Satellites
"If you can have chemical and electrical propulsion in one small package, it's the best of both worlds." – Lead author Amelia Bruno, MIT AeroAstro
Engineers at MIT have demonstrated that a propellant originally developed for chemical propulsion can also power electrospray thrusters, creating a new dual-mode system for small satellites. The breakthrough could significantly enhance the capabilities of CubeSats and other microsatellites.
The Propellant: ASCENT
The propellant, known as ASCENT, was developed by the U.S. Air Force as a green alternative to hydrazine for chemical thrusters. Its key advantage is that it remains stable in space, allowing it to serve both chemical and electrical propulsion systems.
The Technology: Electrospray Thrusters
Electrospray thrusters are dime-sized, fuel-efficient devices that use electric fields to produce thrust from ionized liquid. In tests, ASCENT powered these thrusters with performance similar to conventional ionic liquid propellants, running continuously for up to 100 hours.
The Dual-Mode Advantage
The combined system offers a significant advantage for small satellites. From a single propellant tank, the system can perform both high-thrust maneuvers (e.g., rapid orbit changes) and low-thrust precision adjustments (e.g., station-keeping). This eliminates the need for separate, bulky fuel supplies.
Upcoming Mission: Green Propulsion Dual Mode
The Green Propulsion Dual Mode mission, a CubeSat with one chemical thruster and four electrospray thrusters sharing a single ASCENT tank, is scheduled to launch in November 2025. The mission aims to be the first to test a dual-mode propulsion system on a small spacecraft.
Beyond Earth's Orbit
"This system could pave the way for small satellites to explore beyond Earth's orbit." – Co-author Paulo Lozano, MIT AeroAstro
The technology could enable CubeSats to reach destinations such as Mars or the asteroid belt, significantly expanding the scope of small satellite missions.
Background
- Traditional Approach: Chemical thrusters provide high thrust for short bursts, while electrospray thrusters offer efficient, low-thrust propulsion. Previously, these required separate, bulky fuel supplies.
- The Innovation: ASCENT's stability in space allows it to power both propulsion types, enabling a unified, compact system.