Indian rocket PSLV-XL has successfully launched a pair of European Proba-3 satellites into orbit. They are designed to create artificial eclipses.
Artificial eclipses in space
The Proba-3 mission has been in development by ESA since the beginning of the last decade. Its goal is to study the solar corona, the outer, thinnest and hottest layer of the stellar atmosphere, whose temperature is millions of degrees Celsius. Observations of the corona are seriously obstructed by the fact that it is hidden in the dazzling brilliance of the Sun. Therefore, astronomers have to cut off its light. To do this, a flap called a coronagraph is installed in the telescope.
But the thing is that the light scattered on the elements of the optical system still creates a bright halo around the disk of the coronagraph. This causes a blind spot with a radius of about 2.5 solar disks, making it impossible to see the inside of the corona.
To solve this problem, ESA decided to launch a pair of Proba-3 spacecraft. The first one will act as an artificial moon and cover the Sun, while the second one will study the corona. This approach reduces the size of the blind spot to just 1.1 solar disks.
Proba-3 begins its observations
The Proba-3 satellites were launched on December 5 from the Satish Dhawan Space Center in Sriharikota, India. They successfully separated from the rocket, after which they got in touch with the Earth. The vehicles are in a high elliptical orbit with a perigee of 600 km and an apogee of 60,000 km.
The pair of vehicles will remain attached to each other for the next week while engineers test their systems. The separation should take place in early 2025. After that, the vehicles will turn into a formation with a distance of 150 meters between them. Their position will be measured to the nearest millimeter by a laser system and corrected by a set of high-precision motors.
If all goes according to plan, the first observations of the solar corona will begin about four months after launch. Observations will be made when the satellites are at apogee. According to experts’ forecasts, the duration of the artificial eclipse during one rotation will be up to 6 hours.
Proba-3 has the status of a demonstration mission. Its success will open the way for new, more complex and ambitious projects that will allow astronomers to learn even more about the Sun, the processes taking place in its atmosphere and how they impact the Earth.
Provided by ESA
