content 18-June-2018 19:07:20

EDM Propulsion System Tests

The propulsion system is designed to decrease the final descent velocity (about 80 metres per second, at an altitude of 1400 m) of the EDM to almost zero at approximately 1.5 m above the ground before the engines shut off. It also keeps the EDM in the correct orientation during the final descent phase.

The propulsion system is composed of 9 hydrazine engines of 400 N thrust each, 3 tanks that contain the propellant, and a pressurisation system that maintains constant pressure in each of the propellant tanks. This complex system will operate at high frequencies (each engine will be switched on and off every 100 ms, in order to control the deceleration and ensure the EDM stability), and is designed to manage large propellant flow rates. The complex fluid dynamics at work in the propulsion piping network requires dedicated tests.

Progressive tests of its different elements are planned for the propulsion system:

  • Hydraulic mock-ups to analyse the fluid dynamics within the complex piping network
  • Engine firing tests to verify the engine performance for firing sequences typical of the EDM landing
  • Full scale tests of the propulsion system, with representative piping network and three real engines


EDM fluid dynamics tests with a hydraulic mock-up. Credit: Thales Alenia Space - France Testing the EDM engine in representative landing conditions. Credit: EADS Astrium

The propulsion test activities are performed by Thales Alenia Space - France, led by Thales Alenia Space - Italy, under the close supervision of ESA.

Last Update: 04 April 2014

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