NASA are somewhat at odds with themselves, stating the first launch opportunity is at 6:35 a.m. PDT/ 9:35 a.m. EDT on July 22 (2:35 p.m. BST, 3:35 p.m. CET), yet their countdown to launch clock states the 20th July. I'm assuming the clock is working on updated information and the dates are, um, out of date.

The countdown timer above is based on NASA's countdown timer, but updates more frequently so is less likely to be out of synch with real time. Watch this page for updated information as we move closer to and beyond launch.