Earlier today, NASA announced the winners of contracts for developing spacecraft to send astronauts to the Interantional Space Station. Both Boeing and SpaceX have been awarded contracts, with Boeing receiving $4.2 billion and SpaceX getting $2.6 billion.
I would guess that Boeing received the most because it has a long track record of supplying equipment to the US government. NASA can safely assume that Boeing is capable of completing the contract. SpaceX hopes to be able to do spaceflight cheaper than anyone else but also hasn’t previously been involved in such a major undertaking. The contract shows that NASA is confident that SpaceX can do it, but they also won’t want to risk the whole program by awarding all the money to a company that hasn’t shown itself to be reliable.
Having two options is also a good idea so that a delay in one of them doesn’t necessarily delay the return of NASA-led manned launches. It might also turn out that the two vehicles are better at different things, so maybe some missions will favor Boeing and some SpaceX. Having some competition might also keep costs down.
NASA hopes to have the first launches in 2017, so we’ll still have a couple more years without having manned launch capabilities. Many had criticized the US government for ending the shuttle program because of this gap with no manned launch vehicle. The shuttle was a decades-old design that was very expensive and very risky for the crew, so I think that discontinuing shuttle launches was probably the right move. We should have already had a replacement vehicle ready, but not having one is not a sufficient justification to continue risking astronauts’ lives when safer but not US-led options were available.