ISRO commenced an 8.5-hour revised countdown on Thursday for the European Space Agency’s (ESA) Proba-3 mission. Initially planned for launch at 4:08 PM on Wednesday, the lift-off was postponed to December 5 at 4:04 PM, following a last-minute request from ESA. The launch will take place from the Sriharikota spaceport.
NewSpace India Ltd, ISRO’s commercial arm, secured the contract for this mission from ESA. The Proba-3 mission, short for “Project for Onboard Autonomy,” comprises two satellites Coronagraph (310 kg) and Occulter (240 kg). These satellites will operate in precise formation, separated by just one millimeter, to study the Sun’s corona, its outer atmosphere.
According to ESA, the corona is significantly hotter than the Sun’s surface and is the source of space weather. The Proba-3 mission will contribute valuable data to this area of scientific and practical interest. For ISRO, it is an opportunity to gain deeper insights into conducting solar experiments, following the successful launch of its Aditya-L1 mission in September 2023.
Proba-3 is a technology demonstration mission funded under ESA’s General Support Technology Programme. The instruments onboard the satellites will allow them to orbit closer to the Sun’s rim, with each spacecraft following a 19-hour orbit around Earth. The mission aims to demonstrate precise formation flying, with the two satellites launching in a stacked configuration before separating to achieve their required formation.
The PSLV-C59 rocket, a 44.5-meter-tall vehicle, will carry the satellites. This launch marks the PSLV’s 61st flight and the 26th mission using the PSLV-XL variant, which is typically used for heavy payloads. After an 18-minute journey post-launch, the satellites will reach their designated orbit.
Once in position, the Occulter satellite will block the Sun’s disk, allowing the Coronagraph to study the corona and its surrounding atmosphere in detail. The spacecraft will maintain a separation of 150 meters, operating as a single unit for this advanced scientific observation.
The term “Proba” means “let’s try” in Latin, reflecting the mission’s experimental nature. It is a significant collaboration between ISRO and ESA, advancing solar research and satellite technology.
The Proba-3 mission marks the first ESA-ISRO satellite launch since 2001’s Proba-1 Earth observation mission, showcasing ISRO’s growing prominence in global space exploration through its reliable PSLV platform.
