ISRO reschedules launch of PSLV-C59 due to anomaly detected in PROBA-3 spacecraft

Indian Space Research Organisation (ISRO) has rescheduled the launch of PSLV-C59 to Thursday due to an anomaly detected in the PROBA-3 spacecraft. The launch was set for 4:08 PM on Wednesday.

"Due to an anomaly detected in PROBA-3 spacecraft PSLV-C59/PROBA-3 launch rescheduled to tomorrow at 16:12 hours," said ISRO in a statement on X.

The PSLV-C59 is a joint initiative between ISRO and NewSpace India Limited (NSIL).


Proba-3 is a technology demonstration mission of European Space Agency (ESA). Proba-3 is ESA's and the world's first precision formation-flying mission. A pair of satellites will fly together, maintaining a fixed configuration as if they were a single large rigid structure in space, to prove innovative formation flying and rendezvous technologies.

Read More: ISRO launches PSLV XL Proba 3 Satellite to Sun's Corona

As per the ESA, the mission will demonstrate formation flying in the context of a large-scale science experiment. The two satellites will together form an approximately 150-m long solar coronagraph to study the Sun's faint corona closer to the solar rim than has ever before been achieved. Beside its scientific interest, the experiment will be a perfect instrument to measure the achievement of the precise positioning of the two spacecraft. It will be enabled using a wide variety of new technologies.

Proba-3 will function as an orbital laboratory, demonstrating acquisition, rendezvous, proximity operations and formation flying, while validating innovative metrology sensors and control algorithms, opening up novel methods of mission control. The two satellites will adopt a fixed configuration in space, 150m apart while lined up with the Sun so that OSC blocks out the brilliant solar disk for the CSC. This will open up continuous views of the Sun's faint corona, or surrounding atmosphere, for scientific observation.

Posting about the imminent launch, ISRO wrote posted on its social media platform on X, "Countdown is progressing smoothly as PSLV-C59, an initiative led by NSIL and supported by ISRO's expertise, prepares to launch ESA's Proba-3 satellites into a highly elliptical orbit."

ISRO also highlighted the various stages of the mission, including multiple stages of ignition, the multiple stages of separation of parts until the PROBA-3 satellite gets separated from the launch vehicle.

The mission consists of two spacecrafts, namely Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC) which will be launched together in a "stacked configuration" (one on top of another).

PSLV is a launch vehicle which helps carry satellites other various other payloads to space, or according to ISRO's requirements. This launch vehicle is India's first vehicle to be equipped with liquid stages. The first PSLV was launched successfully in October 1994.

The PSLVC-59 will have four stages of launch, according to ISRO. The total mass which the launch vehicle will be lifting off is around 320 tonnes.

The PROBA-3 is an "In-Orbit Demonstration (IOD) mission" by the European Space Agency (ESA).