June 21

On June 21, 1993, NASA’s Space Shuttle Endeavour launched on mission STS-57 from Kennedy Space Center, tasked with retrieving the unmanned European Retrievable Carrier (EURECA). The flight marked the first shuttle deployment of the Spacehab pressurized module, enabling a variety of microgravity experiments. Astronauts conducted a successful spacewalk to secure EURECA in Endeavour’s payload bay before returning it to Earth for analysis. The mission demonstrated the shuttle’s versatility in satellite servicing and science operations. Over its nine-day flight, STS-57 set the stage for future modular laboratory work on the Shuttle program. The data collected aboard Spacehab contributed to advancements in materials science, biology, and fluid physics in microgravity.

On June 21, 2004, SpaceShipOne, a suborbital spaceplane developed by Scaled Composites and funded by Paul Allen, completed the first privately financed human spaceflight. Piloted by Mike Melvill, the aircraft reached an altitude of over 100 kilometers, securing the Ansari X Prize for non-governmental spaceflight. This pioneering mission demonstrated the potential for private companies to enter the space industry and inspired a new wave of commercial space initiatives. The success of SpaceShipOne paved the way for ventures in space tourism and reusable spacecraft technologies. It also shifted perceptions of space travel, showing that innovation outside government agencies could achieve historic milestones.

On June 21, 2006, the International Astronomical Union formally named two recently discovered satellites of Pluto as Nix and Hydra. These moons had been first observed by the Hubble Space Telescope in 2005, and their names pay homage to mythological figures associated with the god Pluto and the underworld. The designation followed a call for public name suggestions and a scientific review to ensure clarity and consistency in planetary nomenclature. The settlement of these names completed the recognized roster of Pluto’s known satellites at the time, enhancing our understanding of the dwarf planet’s complex system. The discovery and naming of Nix and Hydra offered insights into the formation and evolution of distant celestial bodies.