Motor will allow small satellites to go beyond Earth’s orbit

Engineers in Europe have developed the first prototype of an ultra-compact motor that will allow small satellites to journey beyond Earth’s orbit.

According to a statement, the team from École Polytechnique Fédérale de Lausanne (EPFL) has created a micro motor that can drastically reduce the cost of space exploration.

The compact motor weighs only a few hundred grams and is specifically designed to propel small satellites, weighing from one to 100kg. Conventional thrusters can change a satellite’s orbit around our planet and enable it to travel to more distant destinations, but it is usually used for large and expensive spacecraft.

The team says its prototype will probably be used on CleanSpace One, a satellite currently being developed at EPFL that will clean up space debris, as well as on OLFAR, a swarm of Dutch nanosatellites able to record ultra-low radio-frequency signals on the far side of the Moon.

The prototype weighs approximately 200g, which includes fuel and control electronics. The highly efficient motor can be mounted on satellites as small as 10 x 10 x 10cm3.

‘At the moment, nanosatellites are stuck in their orbits. Our goal is to set them free,’ said Herbert Shea, head of EPFL’s Microsystems for Space Technologies Laboratory and the coordinator of the MICROTHRUST project.

Research into the development of small satellites has intensified in recent times, due mostly to the low cost of production and launch. Small satellites typically cost around $500m (£312m) but the price for larger ones can run into the hundreds of millions.

Nanosatellites were previously limited in their ability due to the lack of an efficient propulsion system. However, EPFL’s MICROTHRUST project is attempting to change this.

The new mini motor does not run on combustible fuel but rather on an ‘ionic’ liquid. In this project, the liquid chemical compound, EMI-BF4, is used as both a liquid medium and an electrolyte. It is made up of ions that are extracted from the liquid and then ejected to produce thrust. In this way, the fuel is expelled, not burnt.

‘We calculated that in order to reach lunar orbit, a 1kg nanosatellite with our motor would travel for about six months and consume 100ml of fuel,’ said Muriel Richard, a scientist in EPFL’s Swiss Space Center.

‘Our prototype still has a few flow problems at the nozzle extremities, which could cause short-circuits,’ Shea concluded.

Researchers from the Netherlands, Sweden and the UK, members of the MICROTHRUST consortium, also contributed to this study.