The contenders

By awarding two companies contracts under the same program, NASA kicked off a new kind of space race. In one corner, we have the SpaceX Crew Dragon, a successor to the original Dragon capsule it's been using to deliver supplies to the ISS. The seven-seater vehicle appears to be quite the looker, with fairly large windows to give passengers a stunningly clear view of their journey -- a feature you'd definitely appreciate if you were a paying customer. The company already has a solid idea of what to do with the capsule outside of its Commercial Crew responsibilities. In fact, it already sold two seats to take private citizens on a trip around the moon next year ... but only if it has already started taking astronauts to the ISS for NASA.

In the other corner, we have Boeing's CST-100 Starliner, which the company has been working on since 2010. Boeing has three different types of Starliners in production, each serving a different purpose. Starliner 1 will remain Earth-bound, specifically designed for ground testing. Its sibling, Starliner 3, will blast off to space for the capsule's first unmanned orbital mission to the ISS. That leaves Starliner 2, which Boeing intends to use for its first manned-flight test.

Both commercial crew partners were on track for a 2017 launch at the beginning of the program, but by the end of 2016, they admitted that they wouldn't be able to stick to their original schedules. NASA had to purchase additional seats on Russian Soyuz rockets for late 2017 and early 2018 to make up for the delay. While it's unfortunate that NASA can't end its reliance on the Russian space agency Roscosmos just yet, the companies had valid reasons to adjust their calendars.

Boeing had to push back its timeline because a Spacecraft 3 dome was damaged during the manufacturing process. Rebecca Regan, the company's Commercial Crew communications specialist, told Engadget that Boeing needed time to identify the root causes of the damage as well as find solutions for it. The company is now looking to launch its first unmanned orbital test flight sometime in the third quarter of 2018; its first manned flight with two astronauts onboard is slated for the fourth quarter.

Things weren't any easier for SpaceX. It, too, was forced to delay its first CCP flights after a Falcon 9 exploded on the launch pad in 2016. SpaceX needed more time to assess the rocket and to investigate the incident with government authorities because Crew Dragon will blast off from a modified Falcon 9. If things go more smoothly for Elon Musk and his team going forward, an unmanned Crew Dragon will be zooming toward Low-Earth Orbit in the second quarter of 2018, while a crewed mission will follow in the third quarter. Both companies will be sending two astronauts to the ISS for their tests flights, which will last for 14 days.