ISRO Set to Launch Proba-3 Mission Today for Groundbreaking Solar Research

Sriharikota: The European Space Agency’s (ESA) Proba-3 mission, aboard Indian Space Research Organisation's ( ISRO ) PSLV-C59 rocket, is all set to lift off from Satish Dhawan Space Centre in Andhra Pradesh's Sriharikota on Thursday, December 5. 

This mission marks a key milestone in ESA-ISRO cooperation, being the first such partnership since the Proba-1 Earth observation mission in 2001.

The mission meant for solar experiment was originally scheduled for launch on Wednesday, however, it was postponed due to an anomaly detected minutes before the launch. The Bengaluru-headquartered space agency had originally planned to launch the Proba-3 mission at 4.08 pm on Wednesday from the spaceport here.

"As per the ESA's request, the launch of PSLV-C59/PROBA-3 has been rescheduled as follows: Date: 05th December 2024 Time: 16:04" (4.04 pm), the space agency announced on Wednesday. The revised launch was earlier fixed at 4.12 pm on Thursday.

According to ESA Director General Josef Aschbacher, the anomaly occurred in the redundant propulsion system of the Coronagraph spacecraft which was onboard the PSLVC59 mission and currently the scientists were involved in identifying the cause of the incident.

"During Proba3's pre-launch preparations at the Satish Dhawan Space Centre in India, an anomaly in the redundant propulsion system of the Coronagraph Spacecraft occurred. This propulsion system is part of the attitude and orbit control subsystem of the satellite and used to maintain orientation and pointing in space." Aschbacher said in a social media post.

"The anomaly is currently under detailed investigation. The use of a software solution by the mission control team at @ESA’s ESEC centre at Redu, Belgium is being evaluated to allow a launch on Thursday 5 December at 11:34 CET (10:34 GMT, 16:04 local time)," he further wrote.

Proba-3 mission: LIVE Links to Watch the Launch

The launch will be streamed live on ISRO’s YouTube channel and ESA’s Web TV.

Dubbed as world's first initiative of its kind, the Proba-3 (Project for Onboard Anatomy) consists of two satellites -- Coronagraph (310kgs) and Occulter (240kgs) -- in which two spacecraft would fly together as one, maintaining precise formation down to a single millimetre to study the Corona, the Sun's outer atmosphere.

The European Space Agency (ESA) said the Corona is much hotter than the Sun itself and it is where space weather originates. It is also a topic of widespread scientific and practical interest.

For ISRO, this launch would provide key insights on taking up scientific experiments on the Sun after its maiden mission--Aditya-L1 which was successfully launched in September 2023.

Proba-3 is a technology demonstration mission funded via the General Support Technology Programme. The instruments onboard the satellites would travel closer to the solar rim for up to six hours at a time and each spacecraft would take up approximately a 19-hour orbit around the Earth.

NewSpace India Ltd, the commercial arm of ISRO has bagged the order from the ESA.

The 25-hour countdown was progressing smoothly since it commenced on Tuesday at 3.08 pm and scientists at the spaceport here have been working on preliminary works for the launch.

'Probas' is a Latin word, meaning 'Let's try'.

The mission objective is to demonstrate precise formation flying and the two spacecraft inside the satellites would be launched together in a stacked configuration after the desired orbit level is reached.

PSLV-C59 is a 44.5 metre tall rocket and is on its 61st flight and the 26th with the PSLV-XL variant which is normally used to place heavy satellites.

The two satellites (Coronagraph and Occulter) would undertake an 18-minute journey to reach the desired orbit.

After reaching the preparatory conditions, the two spacecraft would fly 150 metres apart (as one large satellite structure) in tandem so that the 'Occulter' spacecraft would block out the solar disk of the sun enabling 'Coronagraph' to study the corona of the Sun or the surrounding atmosphere, for scientific observation. 

(With PTI inputs)