Is there life on Terran V? Join the adventure to the fictional planet and find out what it takes to reach the farthest frontiers of deep space.

This video uses a fictional spacecraft and a fictional star system to illustrate a gravity assist manoeuvre – also known as a planetary flyby or swingby. The gravity assist is one of the most important techniques in deep-space navigation. By carefully passing close to a planet, a spacecraft can exchange orbital momentum with the much larger body. From the spacecraft’s perspective, this results in a change in trajectory and a significant boost (or reduction) in speed relative to the star at the centre of the system, without needing to use much fuel.

While the Terran system may be fictional, the physics behind gravity assists is very real. ESA spacecraft such as the Jupiter Icy Moons Explorer (Juice), BepiColombo, Rosetta, Solar Orbiter and Hera carry out gravity assists during their journeys, often at multiple different planets in our Solar System.

Teams at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, carefully plan and execute these manoeuvres to enable ESA missions to reach distant destinations that would otherwise require far more fuel than the spacecraft or its launcher could realistically carry.

By using the gravity of the planets as a slingshot, we can explore space farther, faster and attempt to answer some of the greatest scientific questions of our time.