ESA to Say Goodbye to Gaia and Integral Missions in 2025

In the beginning of 2025 the world’s space science community will see two important mission closures from the European Space Agency (ESA): Gaia and Integral.

The Gaia and Integral missions

These two missions made major contributions to our understanding of space and our solar system. However, the were focused on two very different fields.

About the Gaia mission

The Gaia spacecraft (ref. Figure 1) was launched in December 2013. The main goal was to study our Milky Way and its stellar content and to provide us with highly accurate astrometric and photometric measurements of them. But the satellite did also survey many other objects, like asteroids and minor bodies in our solar system, exoplanets outside our solar systems and many galaxies. This allowed to chart the precise position and velocity, in three dimensions, of almost two billion celestial objects. After more than 10 years of operations the cold gas used to keep the telescope pointing very stably is almost depleted and, end March 2025, the spacecraft will be switched off and put in a safe orbit around the Sun. 

The Integral mission

The Integral spacecraft (ref. Figure 2) was launched in October 2002. The objective of Integral was to explore the most energetic phenomena that occur in nature and address some of the most fundamental problems in physics and astrophysics. By observing gamma and X-rays, which are the fingerprint of the nuclear activities inside the stars, we can better understand the formation and evolution of the stars, novae and supernovae, neutron stars and black holes. Integral is a very long-lived spacecraft with 22 years of uninterrupted observation. It can still work well, but its retirement time has arrived. Like Gaia, it will end its scientific duties in March 2025. 

Orbital Today will look into the Gaia and Integral missions in greater detail as their ends approach. We would like to thank Giuseppe Sarri, Gaia mission Project Manager and Integral mission Payload Manager, for taking the time to tell us about these missions and how they moved science forward.