Successful Solar Orbiter gravity assist manoeuvre at Venus

Since its launch in 2020, Solar Orbiter has carried out a number of gravity assists at Earth and Venus to gradually shrink its orbit and bring it closer to the Sun, but never before has it come as close to a planet as it did on 18 February 2025, when it came within just 379 km of Venus. For comparison, astronauts aboard the International Space Station orbit the Earth at an average altitude of 408 km.
 
“Getting so close to the planet allows us to use its gravity to significantly change the spacecraft’s orbit without using much fuel,” says ESA Flight Dynamics expert Julia Schwartz. “The planets in our Solar System orbit the Sun in the same roughly flat plane. Today’s encounter with Venus will use the planet’s gravity to significantly ‘tilt’ Solar Orbiter’s orbit with respect to that plane. This will grant Solar Orbiter a much better view of the Sun’s polar regions, which cannot be seen from within the plane.” Future Venus flybys, such as the one in December 2026, will further tilt the spacecraft’s orbit and enable high-resolution imaging of the Sun’s entire polar regions.
 
Passing so close to Venus presents a number of challenges for the team at ESA’s European Space Operations Centre (ESOC) in Germany. Precise calculations and minor course corrections were needed before and after the flyby to keep the spacecraft on track. Several parts of the spacecraft have experienced a significant temperature increases, but all components remained well within their design limits.
 
 
During the manoeuvre, Solar Orbiter’s MAG and RPW instruments remained switched on to record the planet’s magnetic and plasma environment. Initial results show that Solar Orbiter has crossed Venus’ ionosphere, which interacts with the solar wind in a unique way.
 
Contact at IAS : Frédéric Auchère
 
Link : ESA press release
 
 

Solar Orbiter’s orbital plane changes thanks to its Venus flyby, improving its view of the Sun's polar regions.