Proba-3 mission launch postponed due to anomaly

“Due to an anomaly detected in PROBA-3 spacecraft PSLV-C59/PROBA-3 launch rescheduled to tomorrow at 16:12 hours,” the Indian Space Research Organisation (ISRO) said.

The launch was progressing as scheduled even at the one-hour mark before the launch.

“Countdown is progressing smoothly as PSLV-C59, an initiative led by NewSpace India Limited (NSIL) and supported by ISRO’s expertise, prepares to launch ESA’s Proba-3 satellites into a highly elliptical orbit,” the space agency had said.

India’s workhorse rocket PSLV was to launch the Proba-3 mission — a pair of experimental satellites that will fly in a formation parallel to each other for long durations to study the outer layer of the Sun’s atmosphere.

The ISRO will launch both the satellites stacked together in a highly elliptical orbit of 600 x 60530 km. Later, the satellites will be separated and put in a parallel orbit.

Satellite instruments designed to study the solar corona — such as the one on India’s Aditya L1 mission — have a coronagraph that looks at the sun and an occulter that blocks the light from the brighter, lower layers of the sun. However, instead of having both as one instrument on a single satellite, Proba-3 mission will have one satellite with the coronagraph and another one with the occulter.

The satellites will be flying in a parallel formation at distances of around 150m from each other for a duration of six hours a day. For the formation, the satellites will use a laser shone from one of the satellites on a reflector on the other, to maintain relative position.

Since it would require too much fuel to remain in formation throughout the day, the two satellites will fly in formation for six hours, separate away and then rendezvous again.