Space shuttle Endeavour has reached its destination. Endeavour docked at the International Space Station on Wednesday morning, two days after blasting off on the next-to-last flight of the shuttle program.
Endeavour and its six astronauts are delivering a $2 billion particle physics detector. Commander Mark Kelly says it's the most expensive payload ever carried by a space shuttle.
At the heart of the Alpha Magnetic Spectrometer is a 3-foot, doughnut-shaped magnet. It will seek out invisible dark matter as well as antimatter. The findings will help explain how the universe formed.
The astronauts will attach the detector to the space station Thursday.
Kelly is married to wounded Arizona congresswoman Gabrielle Giffords.