Press release from the Swedish Space Corporation (SSC)

Green propulsion on Prisma declared GO for autonomous formation flying!

The first of four experimental blocks of the High Performance Green Propulsion (HPGP) system onboard the Swedish Prisma satellites has been successfully completed.
The HPGP system, developed by ECAPS, delivered the expected higher specific impulse compared with a hydrazine system for 10 sec single pulses at similar thrust levels. About 200 pulses were fired ranging from 100 ms to 20 sec and with duty factors of up to 25% during 39 sequences. The accumulated firing time was 14 min.
All test and demonstration objectives for the first experimental block have been met. The HPGP propulsion system is thereby declared GO for Autonomous Formation Flying. /
ECAPS 1 N engine (HPGP)
High resolution image

Point of contact: Mathias Persson, CEO, ECAPS, tel +46 8 627 63 90, +46 70 654 90 80, ,

The next experiment on the Prisma satellites will be Autonomous Formation Flying Early Harvest by the Swedish Space Corporation. Follow the reporting on this experiment and other mission events on

Read more:
ECAPS website,
Prisma website,
SSC’s website,
Images available on
About ECAPS’ propulsion system HPGP
The propulsion system HPGP, High Performance Green Propulsion, uses an ADN based, environmentally benign monopropellant which mainly combusts into water vapour. HPGP has 30% higher performance than the conventional rocket fuel hydrazine. In addition, compared to hydrazine, it has very low toxicity. It is safer and much easier to handle. For fuelling, only light protective clothes are required. When handling conventional fuels, the costs in time and safety are large.
The two rocket engines now demonstrated on Prisma are 1 N thrusters. More powerful engines, ranging from 5 to 220 N, are under development, intended for the same field of application on spacecraft and for launcher upper stages. The development is supported by the Swedish Space Corporation, owner of ECAPS, the Swedish National Space Board and the European Space Agency, ESA. Already before the flight qualification, ECAPS has received contracts for eight engines to American customers amounting to a total value of 450 000 USD.
About Prisma
The Prisma mission will demonstrate break-through technologies for autonomous formation flying and rendezvous, i.e. interaction between space vehicles. The project is financed by the Swedish National Space Board with support from the German and French space agencies. On Prisma, a number of novel systems for guidance, navigation and control are verified, as well as sensors and propulsion systems.

The Swedish Space Corporation (SSC) is the prime contractor for Prisma and has developed the major part of the technology and experiments onboard, as well as the mission control software used for operations.