ESA: Green’ satellite fuel designed to make space safer

On the day running up to launch when a spacecraft is fuelled, ground personnel look more like astronauts than engineers, putting on spacesuit-like protective gear.

This is an essential precaution when dealing with the current hydrazine fuel, but a new development could make satellite fuelling no more dangerous than filling up a car.

First used in rocket engines by the German Luftwaffe during World War Two, hydrazine remains the main propellant of choice for a satellite’s onboard thrusters, used for orbit correction or stationkeeping during its working life.

It is a high-performing storable propellant that is also ‘hypergolic’ – meaning it ignites spontaneously on contact with oxidiser or by itself with a catalyst, which makes a spacecraft designer’s job a lot easier.

Unfortunately hydrazine is also highly corrosive and extremely toxic. When leaked into the environment, it degrades in a few days but has the potential to harm plants and marine life, while exposure is considered harmful to people at just 50 parts per million.

Seeking an alternative, ESA has been working with a Swedish company called ECAPS, part of the Swedish Space Corporation Group, to build and test a thruster that runs on a safer, more environmentally friendly fuel.

ECAPS informs us that the development of High Performance Green Propulsion (HPGP) was initiated with the goal of meeting the requirements for future satellite missions. After more than 10 years of R&D, the HPGP technology is emerging as an enabling technology for improved performance, enhanced volumetric efficiency, reduction of propellant handling hazards and safer launch operations.

The HPGP technology developed by ECAPS, includes a storable monopropellant blend based on Ammonium DiNitramide (ADN) and thrusters with high-temperature resistant thrust chamber and catalyst.

For more information you can download ECAPS HPGP brochure here