ISRO’s PSLV Launches European Sun Satellite Proba-3 with Precision

The European satellite Proba-3 was successfully launched into space on December 5 from Sriharikota, following a delay of its scheduled lift-off on December 4 due to a technical issue.

Proba-3, a state-of-the-art Sun-observing mission, is aboard the PSLV-C59, the flagship rocket of the Indian Space Research Organisation (ISRO). Its primary goal is to enhance global efforts in understanding the economic and technological risks posed by space weather.

Proba-3, which has a two-year mission life, is intended to create an artificial eclipse in order to investigate the Sun’s corona at a completely new scale. (Photo: ESA)

ISRO's next major mission, according to chief S. Somnath, is the Space Docking Experiment (Spadex), which could take place as early as December.

Spadex will involve two 400-kg satellites, named "Chaser" and "Target," launched together aboard a PSLV-class rocket.

Once positioned at an altitude of 700 km, the satellites will perform a highly coordinated rendezvous, culminating in their autonomous docking to form a single unit in orbit.

This manoeuvre is vital for future missions requiring docking, such as space station assembly, satellite refueling, and the transfer of astronauts or cargo between spacecraft.

Understanding Proba 3

‘Proba’ refers to a series of experimental missions carried out by the European Space Agency (ESA), with its name derived from the Latin phrase "Let us try." The journey began with Proba-1, followed by Proba-2 in 2009, which focused on observing the Sun, and Proba-V in 2013, which monitored Earth’s vegetation.

The Proba-3 mission, developed with contributions from teams across 14 European nations and 29 industrial partners, was built at an estimated cost of 200 million euros. Collaborating with ISRO’s commercial arm, NewSpace India Limited (NSIL), which helped develop the launch vehicle, the teams spent over a decade working on the satellites for this mission. Designed for a two-year mission life, Proba-3 aims to create an artificial eclipse to explore the Sun’s corona at an unprecedented scale.

The PSLV-C59 rocket launched two ESA satellites, each weighing approximately 550 kg, into a highly elliptical orbit with an apogee of 60,530 km and a perigee of 600 km, resulting in a 19.7-hour orbital period. The satellites were launched at 4:12 pm from the first launch pad at the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.

Proba-3 Mission Objectives

The newest addition to ESA's series of in-orbit demonstration missions, Proba-3 consists of two spacecraft launched together, which will separate in orbit to perform highly precise formation flying, with an accuracy of just one millimetre, roughly the thickness of an average fingernail.

Proba-3’s ambitious scientific goal is to demonstrate its performance by achieving a highly controlled alignment with the Sun, with the two spacecraft positioned 150 meters apart. One will cast a precise shadow onto the other.

On Earth, total solar eclipses occur only once every 18 months on average and last only a few minutes, requiring solar scientists to travel worldwide to observe them. Proba-3, however, will generate solar eclipses on demand, observing the Sun closer than any previous Earth- or space-based instrument—down to just 1.1 solar radii. It will maintain this observation for six hours of its 19-hour 36-minute orbit.

(This Article was originally published by Business Today)