NASA awarded $4.2 billion to Boeing and $2.6 billion to SpaceX to send astronauts to the International Space Station and return them safely home, with the goal of meeting all of NASA's safety and performance requirements by 2017.
Despite the discrepancy in contract amounts, both companies must meet the same standards, showing that they can safely ferry crew and cargo between Earth and the space station. The spacecraft must also be able to serve as a lifeboat that can evacuate the space station in an emergency.
The certification process includes a test flight to send at least one NASA astronaut to the space station. Once the companies are certified, they will conduct two to six service missions to the space station with a crew of four astronauts. Because these missions will increase the number of crew at the space station, the amount of scientific research done on the space station will double, said Kathy Lueders, manager of NASA's Commercial Crew program.