NASA's newest Martian explorer – the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft – is finally ready for lift-off. Currently poised atop an Atlas V rocket at Cape Canaveral in Florida, the Mars-bound orbiter is slated to launch this afternoon at 1:28 pm ET. Live coverage of the launch begins right now!


Above: A full moon rises behind MAVEN at the Cape Canaveral Air Force Station Space Launch Complex 41, Cape Canaveral, Fla. on Nov. 17, 2013. Image Credit: NASA/Bill Ingalls.

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The countdown to this afternoon's launch from Cape Canaveral Air Force Station Space Launch Complex 41 began bright and early this morning at 6:28 a.m. ET. Continuous coverage can be had on the NASA Launch Blog and NASA TV's coverage of the countdown (streaming above) will begin at 11 a.m. ET sharp. The launch window will be open for two hours, extending to 3:28 p.m.


The second mission under NASA's Mars Scout Program, MAVEN will use its suite of eight scientific instruments to investigate Mars' upper atmosphere. Planetary scientists hope the data MAVEN Collects will help them better understand how the planet lost its thick atmosphere, and went from being warm, wet, and maybe even green to being cold, dry, and famously red.


Today's launch window will be open for two hours, extending to 3:28 p.m. ET. Weather permitting, it will set out on its 10-month journey today, and arrive in Mars orbit in September 2014.

Saddle up, everyone – we're going to Mars! Fingers crossed for a safe and successful launch!