Video: Animation of Vulcan launch

The countdown began Saturday evening and will continue through the start of a simulated launch window opening at 9 p.m. EST Monday. The test started two days late because of predicted arctic weather along Florida’s Space Coast.

Fresh off its first terrestrial test drive, NASA’s Mars 2020 rover was displayed to media last week at the Jet Propulsion Laboratory in California before it’s packed up and flown across the country to Cape Canaveral in February to begin final launch preparations for liftoff in July.

A record number of Atlas 5 launches, the return of Delta 2 and a Delta 4-Heavy at the dawn of a new space exploration era highlighted 2014 for United Launch Alliance.