Isn't SpaceX Under a private own Corporation and not part of NASA?
All three spacecraft are actually designed and built by private corporations... the Dragon v.2 by Space Explorations Technologies (SpaceX), the CST-100 by Boeing / Bigelow Aerospace, and Dreamchaser by Sierra Nevada Corporation. They are competing for NASA's Commercial Crew Development (CCDev) program. NASA want's to not only get out of designing spacecraft, they also want to get away from operating them.
The idea is NASA will tell industry what they want to do, and industry will say "Our rocket model A-1 will do that", and NASA hires that company's services. It's a good way to spur industrialization and commercilization of space. I wish NASA had proper funding and could fund all three spacecraft, but one will win the big funding, with another company getting "research level" funding.
I'm rooting for SpaceX, as it's a local company (Hawthorne CA) that designs and builds the entire system (capsule and rocket) in-house. The Boeing capsule is based on / updated from the Apollo design. Sierra Nevada's spaceplane is based on HL-20 / HL-10 / M2F2 / DynaSoar design. Both Boeing and SD plan on using an Atlas V as launcher, at least initially. Unfortunately, the Atlas uses Russian designed and built rocket engines (the RD-180), and our "good friends", besides overcharging us, have threatened twice to cut off the flow.
As the nation that designed some of the greatest rocket engines and spacecraft ever, we are in a pretty poor spot now.