Comment Re:What else is needed... Rocket engines (Score 5, Interesting) 140
However, the real reasons that astronauts like Chris Hadfield et al think that the Russian Soyuz will be hard to replace are hard to fit into a single post.
- Consider, for instance, that the Soyuz TMA-M can hang around the space station for 6 months, and be ready for use to return astronauts safely back to Earth, without a maintenance crew having to go and check every nut and bolt - a feat that even the Space Shuttle could never muster (for the record, the Space Shuttle had a mission duration of about 12 days - a few Columbia missions went up to 16/17 days).
- Another example is that it takes the Soyuz just 6 hours to go from launch to docking with the space station (for comparison, it took the space shuttle almost 3 days to reach the space station after launch).
- There are many other little things like these that are not cool or sexy, but make the ruthless efficiency and effectiveness with which the Soyuz executes and fulfils its purpose is second to none. It will take a lot more than a larger tin-can and a more comfortable ride to convince astronauts to put their lives in SpaceX's hands.
OK, keep in mind orbital parameters. The ISS's orbit was specifically placed the way it was to allow the Russians to get to it with ease. It's on a steep incline that takes orbital corrections to manuver to from any other launch site than Baikanour. It passes directly over Canaveral occasionally, but the delta-v required to do a one shot insertion orbit to ISS from Canaveral is expensive. That's why the Shuttle was downrated for ISS missions in payload and duration.
Shuttle was also a hell of a lot more complicated than a Soyuz capsule. It's like comparing a Prius to a Model T. Soyuz was designed for no-frills get them to orbit. Shuttle was designed to get a shitpile of cargo to orbit along with the crew and the gear to operate independently of anything once there. Think of it more like a spacegoing Winnebago.