The final Endeavour launch — which could be the final space shuttle launch — was slated for April 19th but had to be moved 10 days primarily because of a scheduling conflict. The Russian resupply space vehicle is also scheduled to be docked at the International Space Station during that time and the station is not outfitted to support two docked vehicles. Apparently Russia doesn’t know how to share Google Calendars.
The delay also allows NASA to repair slight damage recent Florida storms caused to the protective foam on the shuttle’s external fuel tank. But if all goes as planned, the youngest of all the Space Shuttles is set to blast off from the Kennedy Space Station for the very last time on April 29th. Sad.
Image from Wikipedia and here’s a link to a massive version in case you want to make a poster.