Crater from India's first atomic bomb

The device used a high explosive implosion system, developed at the Defence Research and Development Organisation (DRDO)'s Terminal Ballistics Research Laboratory (TBRL), Chandigarh, based on the American design from World War II. But the Indian design was simpler and less sophisticated than the American system. The 6 kg of plutonium came from the CIRUS reactor at BARC, Trombay, Mumbai (then Bombay). The neutron initiator was a Polonium-Beryllium type (again like those used in early U.S. bombs of the Fat Man type) code-named "Flower." The complete core was assembled in Trombay before transportation to the test site. Prof.Dr. Abdul Kalam, was the pioneer behind the launch. An aeronautical engineer from Tamilnadu paved the way for India's ascent into an elite group of Nuclear states. Fondly called as 'Missile Man of India'

The fully assembled device had a hexagonal cross section, 1.25 m in diameter and weighed 1400 kg. The device was detonated at 8.05 a.m. in a shaft 107 m under the army Pokhran test range in the Thar Desert (or Great Indian Desert), Rajasthan. Coodinates of the crater are [show location on an interactive map] 27°05′42″N 71°45′11″E / 27.095, 71.753. Officially the yield was reported at 12 kt, though outside estimates of the yield vary from 2 kt to 20 kt. Pokhran is the test site for India's nuclear program.