ICT Desk

Two European satellites were launched into orbit on Thursday, marking the first mission designed to create artificial solar eclipses using advanced formation flying in space, reports AP.

Starting next year, each artificial eclipse will last approximately six hours, significantly longer than the brief totality of natural eclipses on Earth. This extended duration will allow scientists to study the sun's corona, its outer atmosphere, in greater detail.

The satellites were launched from India.

“We are a very happy science team here,” said Joe Zender, mission scientist for the European Space Agency (ESA), via email.

As part of a technological demonstration, the satellites will separate in about a month and maintain a formation 492 feet (150 meters) apart. Once positioned high above Earth, one satellite will align with the sun and cast a shadow on the other.

Achieving this requires extreme precision, with alignment accuracy within one millimetre — about the thickness of a fingernail, according to ESA. To maintain this positioning, the satellites will use GPS, star trackers, lasers, and radio links to fly autonomously.

Each satellite is cube-shaped, measuring under 5 feet (1.5 meters) across. The shadow-casting satellite carries a disk designed to block sunlight from the telescope on the other satellite. The setup mimics the effect of a natural total solar eclipse, with the blocking satellite resembling the moon and the telescope-equipped satellite representing Earth.

“This has a huge scientific relevance in addition to testing high-precision formation flying,” said Dietmar Pilz, ESA’s director of technology and engineering.

Scientists need the sun’s face entirely obscured to study the corona, particularly its wispy structure near the solar rim. They aim to understand why the corona is hotter than the sun’s surface and to investigate coronal mass ejections — massive eruptions of plasma and magnetic fields. These events can trigger geomagnetic storms that disrupt power and communication systems on Earth while producing spectacular auroras in unexpected regions.

The satellites will follow an elliptical orbit ranging from 370 miles (600 kilometers) to 37,000 miles (60,000 kilometers) from Earth. Completing an orbit will take nearly 20 hours, with six hours at the farther end dedicated to creating eclipses. Other orbits will focus on formation flying tests, ESA reported.

The first eclipse data is expected in March after initial spacecraft checks.

According to Zender, eclipses will be generated at least twice weekly, with six hours of totality per event for corona observations. The frequency will depend on solar activity, providing significant opportunities for research compared to the fleeting three to five minutes of totality during natural eclipses.

The $210 million mission, named Proba-3, aims to achieve at least 1,000 hours of “on-demand” totality over its two-year operational period. Afterward, the satellites will gradually deorbit and burn up in Earth’s atmosphere within approximately five years.

A last-minute issue with the backup propulsion system on one satellite, critical for precision flying, delayed liftoff by a day. Engineers resolved the problem with a software fix, ESA confirmed.