ESA's Juice Spacecraft to Fly Past Earth on 28 September for Its Third Gravity Assist
ESA's Jupiter Icy Moons Explorer will pass within 8,640 km of Earth on 28 September 2026, gaining about 3.5 km/s and a 20-degree deflection on its route to Jupiter.
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Based on an official announcement · Source: European Space Agency
Developing. This story covers a scheduled or ongoing event and will be updated when the sources publish more. Last updated .
What happened
The European Space Agency announced on 21 September 2026 that its Jupiter Icy Moons Explorer, Juice, will return to Earth on 28 September for a gravity assist. Flight controllers will guide the spacecraft close to the planet to change its speed and direction on the way to Jupiter.
What we know
- Closest approach is 8,640 km above Earth, over the Indian Ocean, at 13:45 CEST (11:45 UTC, 17:15 IST). In the 15 to 30 minutes before that, Juice passes over Australia from north-east to north-west, and ESA says amateur astronomers with suitable equipment may be able to track it.
- The flyby deflects the trajectory by about 20 degrees and adds about 3.5 km/s. It sets up a final Earth flyby in January 2029 and arrival at Jupiter in July 2031, with orbit around the moon Ganymede planned for 2034.
- Juice launched in April 2023 and has already completed the first lunar-Earth flyby and a Venus flyby.
- A navigation campaign began on 17 August with six slots for small trajectory corrections. Spacecraft Operations Manager Angela Dietz is quoted: "Until now, only one manoeuvre at minus four weeks was needed." An emergency manoeuvre slot at 08:00 CEST on 28 September exists in case of navigation errors or a collision risk with other satellites.
- From 21:24 CEST on 27 September to 06:03 CEST on 28 September, Juice is in Earth's shadow and runs on battery, so the team is prioritising the most important instrument observations during that window.
- All ten science instruments will collect data on Earth and the Moon between 23 September and 3 October.
What is not yet confirmed
The flyby has not happened yet. Timings above are ESA's plan as published on 21 September; the outcome, any use of the emergency manoeuvre, and the science return will only be known after the event. This story will be updated when ESA reports the result.
Why it matters
Gravity assists are what make an outer-planet mission affordable: a direct flight to Jupiter would need a far larger rocket and most of the propellant just to slow down on arrival. Each flyby spends nothing but time, and this one is the second-to-last before the long cruise to Jupiter.
Sources
This summary was written from the documents below. Read the original before relying on any detail.
- Juice to fly past Earth for third gravity assist(opens in a new tab)
European Space Agency · Official announcement · esa.int · published
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