 Between the 1970s and 1990s, Kalam made an effort to develop the Polar Satellite Launch Vehicle (PSLV) and SLV-III projects, both of which proved to be successful.Kalam was invited by Raja Ramanna to witness the country's first nuclear test Smiling Buddha as the representative of TBRL, even though he had not participated in its development.In the 1970s, Kalam also directed two projects, "Project Devil" and "Project Valiant", which sought to develop ballistic missiles from the technology of the successful SLV programme.