NASA is preparing to launch its next Mars rover, Curiosity, on August 5. But safely reaching the surface of the Red Planet is no short order.
The operation is filled with engineering challenges described in this video put out by the agency's Jet Propulsion Laboratory.
How difficult is the mission?
Well, entry, descent and landing is what those in the space world call "the seven minutes of terror." That's because the rover has seven minutes to get from the top of the atmosphere to the surface of Mars going from 13,000 miles per hour to zero. Meanwhile, 76 pyrotechnic devices must fire at exactly at the right time, including the ejection of a supersonic parachute, with absolutely no help from the ground.
Don't forget the surface of Mars doesn't exactly come with a neat little landing strip; it's filled with all sorts things that get in the way like large rocks, craters and dust.
Mars also has a very thin atmosphere (1/100th the atmospheric density of Earth), which makes it really hard to slow down (hence: the heavy-duty parachute).
Basically, you only get one shot to land on Mars.