This IAF pilot chased the sun's shadow

For an Indian Air Force (IAF) fighter pilot chasing a target at Mach 2.5 or more than twice the speed of sound and yet not managing to play catch seems like something out of a sci-fi film. But for Air Marshal S. Mukerji, chasing the sun's shadow during the total solar eclipse on Oct 24, 1995, that's exactly what happened.

Heralding the IAF's participation in scientific study of total solar eclipse, Mukerji, presently the Air Officer-in-Charge Personnel at Air Headquarters and the then commanding officer of IAF's only MiG-25 reconnaissance squadron based at Bareilly, undertook a sortie in the giant plane to record the celestial event. He got the rare opportunity to film the Sun's corona from an astounding altitude of 80,000 feet.

"We flew at Mach 2.5 in the path of the eclipse at 80,000 feet along the planned central axis of the eclipse over Neem ka Thana (in Rajasthan's Sikar district)," recalled Mukerji of his historic sortie.

The sortie finds a mention in his flying log book simply as "Supersonic Profile".

"The weather and visibility were not any constraints as clarity at stratospheric levels is far better than that nearer the ground," he said.

After the total solar eclipse of 1898 over India, the next occurrence took place in 1980. And in the subsequent total solar eclipse in 1995, the IAF assisted the Department of Science and Technology (DST) in their quest to film this celestial alignment. This was possible with aviation speeds streaking way past the supersonic barrier.

With a manual camera mounted above the instrument panel, a special lead and button provided to the other pilot, Wing Commander Y.S. Babu, seated in the front cockpit, the duo, with special solar filters on their visors flew straight towards the Sun for a minute and 24 seconds, photographing never-before seen images of the spectacle during the total solar eclipse.

"A lot of preparation went into the sortie. It had to be charted and axis programmed on the inertial navigation system, with briefings by scientists armed with NASA charts. The aircraft was first jacked up and the angle-of-attack simulated on the ground to harmonize the camera along the axis.

"In addition, the aircraft's belly camera could capture the shadow beneath that was 85 km in width," Mukerji explained.

During Wednesday's eclipse, a 10-member team of scientists and a camera team will be flying in an AN-32 transport aircraft from the Agra airbase in an endeavour to film the event. The aircraft will fly along the central axis on a north-westerly direction at an approximate altitude of 25,000 feet, turn around at Khajuraho and land back at Agra.

This apart, a Mirage-2000 trainer will also take off from the Gwalior airbase and the pilot in the rear seat will take photographs as the fighter flies on an angular track to the central axis of the Sun's shadow.