NASA's space shuttle will be retired after the International Space Station is completed next year leaving manned space missions mostly in Russia's hands. "NASA launch managers this morning cleared space shuttle Endeavour to lift off before dawn Sunday from Kennedy Space Center in Florida, one of the five remaining flights before the shuttle program concludes this year or early next. The planned launch comes less than a week after the future of human spaceflight in the U.S. was shaken by President Obama, whose budget request for fiscal year 2011, released Monday, would cancel Constellation, the planned successor to the shuttle. The final space shuttle mission is scheduled for September 16, but the probability of weather or technical delays in the intervening months make that launch likely to slip into 2011. Once the shuttle is retired, NASA will rely on the services of foreign partners, namely Russia, for manned missions in the near future. With Obama's plan, commercial firms would instead step in once they demonstrate the ability to safely and cost-effectively deliver astronauts to orbit."