Mark 21 nuclear bomb
The Mark 21 nuclear bomb was a United States nuclear gravity bomb first produced in 1955. It was based on the TX-21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954. While most of the Operation Castle tests were intended to evaluate weapons intended for immediate stockpile, or which were already available for use as part of the Emergency Capability Program, Castle Bravo was intended to test a design which would drastically reduce the size and costs of the first generation of air-droppable atomic weapons (the Mk 14, Mk 17 & Mk 24). At long, in diameter, and weighing , the Mk-21 was half the length and one-third the weight of the Mk-17/24 weapons it replaced. Its minimum yield was specified at four megatons.
Anastasio Ballestrero
Ballestrero agreed to scientific testing being performed on the Shroud of Turin in October 1978 but refused to permit radiocarbon dating testing as it required removing samples from the shroud itself. Once technical improvements made it possible to use samples the size of postage stamps the cardinal permitted samples to be cut in April 1988 which he himself supervised to ensure it was carried out in an appropriate manner. These would be tested in three labs in Switzerland as well as in the United States and the United Kingdom.