The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
Go to topicAfter entering geostationary transfer orbit, the main engine of the Mercury Transfer Module will fire to boost the apogee (point of furthest distance from the Earth) of the Mercury Composite Spacecraft. The chemical engine will be fired around perigee (point of closest approach to the Earth) - indicated by the red tracks in the orbit animation.
Having reached the orbit of the Moon, a lunar gravity assist will next set the composite spacecraft on its interplanetary trajectory toward Mercury. Shortly after, the MTM's solar array is fully deployed and the advanced solar electric propulsion system is activated.
In the animation, all four ion engines are seen firing, whereas in reality only one will be switched on due to the limited power that is available. The exact direction of thrust can be selected by the steerable nozzles of the ion engines.