1894day.year
Norway formally adopts the Krag–Jørgensen bolt-action rifle as the main arm of its armed forces, a weapon that would remain in service for almost 50 years.
Norway adopts the Krag–Jørgensen bolt-action rifle as its standard service weapon, a design that would remain in use for nearly five decades.
On April 21, 1894, the Norwegian government officially adopted the Krag–Jørgensen bolt-action rifle as the primary infantry weapon for its armed forces. Designed by Ole Herman Johannes Krag and Erik Jørgensen, the rifle featured a smooth action and unique magazine system that allowed rapid reloading. Its selection followed rigorous trials comparing domestic prototypes with foreign arms, underscoring Norway’s commitment to self-reliance in defense procurement. Over the next forty-nine years, the Krag–Jørgensen proved reliable in harsh Nordic conditions and influenced rifle development worldwide. The adoption marked a milestone in military technology for Norway, combining innovative engineering with national industrial capability.
1894
Krag–Jørgensen
1964day.year
A Transit-5bn satellite fails to reach orbit after launch; as it re-enters the atmosphere, 2.1 pounds (0.95 kg) of radioactive plutonium in its SNAP RTG power source is widely dispersed.
A Transit-5bn satellite fails to orbit on April 21, 1964, dispersing radioactive plutonium over the Pacific.
On April 21, 1964, the U.S. Navy launched the Transit-5bn navigation satellite from Vandenberg Air Force Base. The mission failed to achieve orbit, causing the spacecraft to re-enter the atmosphere and disperse its SNAP RTG power source. Approximately 0.95 kg of radioactive plutonium was released into the environment over the Pacific Ocean. This accident raised concerns about the safety of nuclear power sources in space missions. Investigations led to improvements in launch procedures and containment of radioisotope generators. The incident influenced future satellite design and policy on spaceborne nuclear materials.
1964
Transit-5bn
plutonium
SNAP
RTG
1972day.year
Astronauts John Young and Charles Duke fly Apollo 16's Apollo Lunar Module to the Moon's surface, the fifth NASA Apollo Program crewed lunar landing.
Apollo 16's lunar module touches down on the Moon on April 21, 1972, marking NASA's fifth crewed landing.
On April 21, 1972, astronauts John Young and Charles Duke piloted the Apollo Lunar Module Orion to a smooth landing in the Descartes Highlands of the Moon. This mission, part of NASA's Apollo Program, aimed to explore lunar geology and test scientific instruments on the surface. Over their three-day stay, Young and Duke collected rock samples, conducted experiments, and deployed the first lunar surface television camera. They reported clear skies and stunning views of lunar terrain. Apollo 16's success further demonstrated human capability in space exploration. The mission's findings expanded scientific understanding of the Moon's highlands and volcanic history.
1972
John Young
Charles Duke
Apollo 16
Apollo Lunar Module
Apollo Program