Click on events in the timeline for more details.

SpaceX's upcoming launch of the Dragon spacecraft to dock with the International Space Station is finally happening. Probably.

Originally, SpaceX thought this flight could take place in 2010, but that was later changed to the summer of 2011 and then the fall and winter. This year alone the launch date slipped from Feb. 7 to April 30, and then May 7. Such delays are inevitable in the complicated business of space.

Back in 2004, companies like Virgin Galactic were optimistically forecasting regular private tourist flights in 2007. Here we are five years later and such launches won't start until next year at the earliest. And NASA is certainly no stranger to mission delays – their James Webb Space Telescope was originally envisioned to launch in 2007, though now the agency is pushing for a 2018 launch date.

Despite some postponement, SpaceX has already accomplished a lot. The company has built two rockets; the smaller Falcon 1 launch vehicle can take about 1,500 pounds to low-Earth orbit while its larger counterpart, the Falcon 9, can carry 23,000 pounds. (The Space Shuttle, in comparison, could launch slightly more than 53,000 pounds).

The Dragon capsule, which sits atop the Falcon 9 rocket, is the first reusable spacecraft built by a private company and should one day ferry supplies and crew to the International Space Station. SpaceX also has plans to develop the beefed-up Falcon Heavy rocket, which would be capable of bringing 120,000 pounds to space.

In the timeline above, Wired takes a look at some of the company's past triumphs and tribulations as well as their preparations – no matter how tenuous – for the future.