The mission is complete. Astronauts on the Endeavour space shuttle  has placed the final part of a robotic arm onto the International Space Station. The task was completed after logging in over 1,000 assembly hours. The final completion was 12 years in the making since the project started in December 1998. This marks the last spacewalk and flight for the Endeavour. 

The detachment and reattachment onto the space station was performed by astronauts Greg Chamitoff and Mike Fincke. The robotic crane  costs $200 million, which needed to be attached to a 12 foot tall robot weighing over 3,400 pounds. Chamitoff marveled at the giant space station after its completion. 

Twelve years of building and 15 countries and now it's the Parthenon in the sky and hopefully the doorstep to our future....So congratulations everybody on assembly complete, said Chamitoff.  We're floating here on the shoulders of giant...This space station is the pinnacle of human achievement and international cooperation.

The Endeavour crew completed four spacewalks in one week and plans to return back to earth in about 5 days. The Endeavour and shuttle crew's final return flight home will mark Nasa's second to final flight. The Endeavour space shuttle will be handed over to museums in California once it touches back down to earth.