[Update] The Curiosity rover appears to have landed successfully.

If you think your testing job is stressful, you have no idea what the folks at NASA’s Jet Propulsion Laboratory are feeling tonight. That’s because in less than 12 hours, the Mars Science Laboratory will begin its harrowing descent into the Martian atmosphere. The payload for this mission is a rover named Curiosity. It’s small by Earth standards, but it’s huge compared to anything we’ve sent to Mars before.

Since Curiosity is so large and heavy, it presents some new challenges for landing on Mars. Past rovers landed using giant airbags which inflated right before impact, allowing them to bounce across the terrain before coming to a stop. That won’t work this time because Curiosity is simply too large and heavy.

For this trip, NASA is using a brand new approach called the “sky crane” technique. The rover will land using a complicated arrangement of parachutes, thrusters, and a mechanism where a flying carrier will lower the rover to the surface on long cables. This carefully orchestrated dance will be incredibly prone to error; and any bug, mistake, or glitch in the software or hardware could mean the end of a mission costing $2.5 billion. Take a look at this video to see the details:

While every single component of Curiosity has been checked and rechecked, there’s no way to truly test it until it reaches its destination. Mars has so many differences compared to Earth – lower gravity, a thinner atmosphere, and no magnetic field. In a system as complicated as the sky crane, there’s no way to know how it works until the time comes for it to land. In the past, just 15 out of 39 missions to Mars have succeeded.

Interested in watching the landing? The whole thing happens on Monday, August 6 at 05:31 UTC. You can follow the landing on Twitter or watch NASA TV online (they even have NASA TV apps for iOS and Android). And if you want to hang out with like-minded space nerds, Gizmodo has the scoop on landing parties happening around the world.