On Thursday, March 10, the Space Shuttle Endeavour began its last 5 km trek to the launch pad.

When it launches on April 19 (scheduled at 19:48 EDT), Endeavour will bring parts and supplies to the International Space Station, as usual, but it will also be carrying the 7 ton the Alpha Magnetic Spectrometer-2, a scientific instrument that, among many goals, will try to detect antimatter (to solve a long-standing puzzle of why so little exists in our Universe) and look for the subatomic signature of dark matter. This will be Endeavour's final scheduled flight. Image Credit: NASA/Jim Grossmann