OTD…Sept. 20 and Endeavour retirement

A last-of-its-kind piece of space hardware — the only remaining shuttle external fuel tank — makes its way along the city streets of Los Angeles to the California Science Center.

#OTD in 2009, shuttle Discovery delivers power payload to space station.

The flight of Gemini 4 launched today in 1965 for NASA’s first Extra Vehicular Activity spacewalk by Ed White on a four-day orbital mission with commander Jim McDivitt.