UPDATE: Due to a valve issue, today's launch is delayed 24 hours to Friday, Dec. 5th at 7:05am EST.
At 7:05am EST on Thursday December 4, 2014, the Orion spacecraft sitting atop a Delta IV Heavy rocket will be launched from Cape Canaveral. Over the course of 4 hours, it will orbit the Earth twice and reach a peak altitude of 3,609 miles (or 15-times higher than the International Space Station). Finally, it will be aimed back at the Earth and hit the atmosphere at 20,000 mph where its heat shield will have to withstand temperatures around 4,000 degrees.
Orion is the crew module that is slated to send humans back to the Moon, to asteroids, and eventually to Mars. The Dec. 4th launch will test flight controls, re-entry, and radiation levels.
You can watch it live on NASA TV! (via NASA)
A schematic of the Dec. 4th test. Image: NASA