On this day in 1970, the NASA command module Odyssey blasted off from the Kennedy Space Center, bringing a start to the Apollo 13 mission. Two days after liftoff, an oxygen tank would explode within the module, thwarting the mission's intended lunar landing and leading astronaut Jack Swigert to utter the second-most famous phrase in the history of space exploration: "Houston, we've had a problem." Pictured above is NASA's diagram of that module.

Below, recent Pictures of the Day:

Image: NASA.