Overview
Our MicroThrust proposal addresses the FP7 target for advanced in-space propulsion technologies for solar system exploration. This research provides a key component in facilitating exploration missions: a technology that can substantially reduce the cost of undertaking particular types of robotic exploration. Building on the framework of a successful ESA study, our team of leading academics, research institutions and space companies has developed a conceptual design of a very small, yet highly performant electrical propulsion system. The conceptual design is based upon experimental data already obtained by team members. As a result we are confident that this system can provide the transportation element for taking nano/micro satellites to any location in the Earth-Moon system and will even allow missions to nearby planets and asteroids. The propulsion system will thus permit new exploration mission concepts. These missions due to their size will be developed within a fraction of the time for conventional missions. Their simplicity, perhaps even single instrument spacecraft, will reduce risk for carrying out the mission. Overall this will dramatically reduce cost of individual missions, thus providing more flight opportunities for planetary scientists and planetary exploration.
To achieve these goals the propulsion technology has high performance at low mass and low power demand. The propulsion system is a microfabricated colloid thruster having a high degree of subsystem integration. Our work so far has demonstrated the capability of this concept to have a radically reduced part set making substantial progress towards a thruster-on-a-chip. Our experienced team will take the technology through to the significant position of having tested and fully characterized a breadboard model. The design approach is that this is also a proto-flight model such that gaining the final step of a flight test for the hardware is low risk and low development cost.
Funding
Results
Small satellites reaching for the stars
Sending a satellite into space and placing it in orbit takes hundreds of thousands of litres of fuel. What if all this propellant wasn't necessary?
European scientists with the http://microthrust.eu/ (MICROTHRUST) project have designed a tiny motor that runs on an ionic liquid, specifically EMI-BF4.This compound is composed of electrically charged molecules called ions and is liquid at room temperature.
The ions are extracted from the liquid and then ejected by means of an electric field to generate thrust. This is the principle behind the MICROTHRUST ionic motor: fuel is not burned, it is expelled.
In the motor developed, ionsare emitted from an array of tiny silicon nozzles — more than 1 000 per square centimetre. The fuel is first guided from a reservoir to the extremity of the micro-nozzles, where the ions are accelerated and finally emitted out the back of the satellite.
The ion ejection system requires high electrical voltage, and the available energy aboard a nanosatellite is limited to a few small solar cells (or about 4 W of power). This difficulty was overcome with the miniaturisation of the system. The tiny motor was not built to blast satellites into orbit; instead, it was designed to help spacecraft manoeuvre once they are in space — something that previously required bulky expensive engines. The new, ultra-compact motor will allow satellites to shift direction while orbiting at 40 000 km/h.
MICROTHRUST'S first prototype of the motor has already made its way out of the laboratories and may be tested under real world conditions with the CleanSpace One mission — a nanosatellite under development to clean up space.
Nanosatellites are much cheaper than their bigger counterparts, but currently lack an effective propulsion system and are thus stuck in their orbit around Earth. Project outcomes could usher in a new era of low-cost space exploration.