The National Aeronautics and Space Administration (NASA) is the US government agency that is responsible for the civilian space program and aeronautical research. It was established by President Eisenhower in 1958 run by civilians rather than military ) to promote peaceful exploration of space. The agency replaced the The National Advisory Committee for Aeronautics. Since then, NASA has had the lead in manned and unmanned space missions including Mercury, Gemini, Apollo, Sklab, the space shuttle and the International Space Station. Under their unmanned programs, they championed earth orbiting satellites, interplanetary probes and space science missions. In recent years, many of their functions have been contracted to private companies. Their most recent goal is to return to the moon in the next decade.
In The Big Bang Theory, NASA has tasked Howard with his various missions, building things to go into space, journeying to the space station, making speeches and representing NASA as one of their astronauts. Howard also works the Jet Propulsion Laboratory, a NASA facility.
In "The Lizard-Spock Expansion", Howard wrecks the NASA [[Mars Rover] and then erases all the evidence. Later his actions cause NASA to discover that there was life on Mars, but the agency doesn't know who to thank.
In "The Werewolf Transformation", Howard reports to Houston for his astronaut training which he suffers through.
In "The Friendship Contraction", Howard shows the guys the official NASA press release announcing his mission to the space station.
In "The Holographic Excitation", Howard gives out autographed copies of his official NASA portrait.
In "The Table Polarization", NASA asks Howard to return to the space station to repair the telescope which he is excited about. Bernadette has an intervention to convince him not to go since he was so miserable there.
In "The Friendship Turbulence", Howard offers to take Sheldon to Houston for a tour of NASA headquarters where he is speaking.
In "The Mommy Observation", Howard gives a talk at NASA's Houston Manned Spacecraft Center and gives Sheldon a tour.