Update: They just had an ignition failure, but it looks like they're going to give it another go in a few minutes.
Update 2: And it's away! Apart from that slight hiccup on the first attempt (and a parachute that didn't quite fully deploy), it's looking like the launch was a complete success. We're also still waiting for confirmation on exactly how high the rocket got, but the team is apparently pleased with the results regardless. Head on past the break for a video of the launch.