 Complete the following phrase:  P. Radhakrishan Nair, Paramaswaran Radhakrish is a veteran space scientist, author and speaker from India. He retired from the Indian Space Research Organisation as the Deputy Director of Liquid Propulsion Systems Centre. Radhakrish was one of the two trainees slated to travel to space in the STS-61-I Challenger mission in September 1986 as a Payload Specialist for INSAT-1C, but the flight was cancelled after the 