Proba-3: Twin spacecraft will launch to create an artificial solar eclipse

The European Space Agency (ESA) is aiming to create an artificial eclipse in space with the Proba-3 mission, which will help study the sun and demonstrate a highly precise formation in one millimeter in flight.

Scheduled to launch on December 4 on India’s PSLV-XL rocket, the mission consists of two spacecraft. After launch, they will be placed in a highly elliptical orbit around the Earth, 600 kilometers from the planet, but 60,000 kilometers from it.

One spacecraft, called the Occulter, is equipped with a 1.4 meter wide disc made of carbon fiber and plastic. The other spacecraft will fly about 150 meters behind the first one, with a camera pointed at it. From this vantage point, Occulter’s disk will block the surface of the sun, just as the moon appears to cover the sun. total solar eclipse. This allows him to see the visual arts solar crownthe atmosphere of the sun in unprecedented detail.

“The corona will be the closest we’ve seen to the Sun in visible light,” says Damien Galano, ESA’s Proba-3 mission manager. “This can give us detailed information about the temperature of the corona, the generation of the solar wind and how the corona spreads out into space.”

Proba-3 will achieve this feat by flying with incredible precision. Both spacecraft are loaded with sensors to track their position in space and Occulter will use 12 nitrogen thrusters to autonomously maintain position with its partner to within a millimeter of accuracy. The thrusters can only put out 10 millinewtons of thrust, 50 times less force than a human breath.

Each artificial eclipse will last 6 hours when the spacecraft is farthest from Earth to limit the destabilizing effect of Earth’s gravity. More than 1000 eclipses are predicted during the two-year mission. Galano says this is the first artificial eclipse experiment in space since an attempt was made Apollo-Soyuz Test Project in 1975.

The experience gained from the Proba-3 mission may have applications in resupplying spacecraft, developing large telescopes in space, etc. “So far, we’ve been able to do it to within a centimeter or so,” says Steve Buckley, chief engineer for Proba-3 at US company Onsemi, which developed some of the mission’s sensors. “This is 10 times better.”