It's the 12th annual Space Day, even, which is held every year by NASA and Lockheed Martin. The theme this year is "Celebrating Human Space Flight: Past, Present and Future." I think that theme is pretty discriminatory actually, since it's clearly designed to gloss over the animals that have made for our swashbuckling space glory possible. And of course, the greatest animal hero of them all, Spacebat.
But if you're okay with leaving them out, you can join NASA's prejudiced, self-congratulatory celebration at the Smithsonian, which will have a live broadcast from the International Space Station. [Space Day via io9]