Space Exploration

Chandra

Chandra X-Ray Observatory

On July 23, 1999, NASA launched the Chandra X-Ray Observatory to observe x-rays from outside the Earth’s radiation field. The mission was originally intended to last just five years, but Chandra is still orbiting the Earth and making discoveries today, more than 20 years after launch.

Melvin Calvin stamp

Birth of Melvin Calvin

Biochemist Melvin Calvin was born on April 8, 1911, in St. Paul, Minnesota. He earned the 1961 Nobel Prize for Chemistry for his discover of the Calvin cycle – the conversion of carbon dioxide into organic molecules during photosynthesis.

Skylab

On July 11, 1979, Skylab, the first manned US space laboratory, returned to Earth after six years in space.