If you want to watch live coverage of the Orion liftoff, check out the following links:
The liftoff has already been delayed several times due to wind, core engine temperature readings and a fuel and drain valve that did not close. Let's hope there is a launch today within the time window remaining.
For those of you who don't follow NASA's activities, Orion is an unmanned flight that will launch atop a Delta IV heavy rocket. It will be a two-orbit, four-hour flight followed by landing in the Pacific Ocean. The launch will be at Cape Canaveral in Florida, and will be a flight test of the systems that are most critical to safety. The ultimate and future goal is to take astronauts further into space than they've ever gone before.