How Things Work: Dropping in on Mars
NASA's Curiosity rover will try a new way of landing on another planet.
- By Tony Reichhardt
- Illustrations by Harry Whitver
- Air & Space magazine, January 2012
If the giant, bouncing airbags that delivered NASA’s previous rovers (Sojourner, Spirit, and Opportunity) to the Martian surface initially made some people nervous, the Sky Crane maneuver designed for the new Curiosity Mars Science Laboratory looks every bit as scary—at first. The most advanced and expensive rover ever sent to Mars, the $2.5 billion Curiosity will be lowered from a hovering, thrusting descent stage, on a bridle of three nylon cords, to a soft touchdown on the surface. No landing platform required: This explorer will start off on its own wheels. It may seem treacherous, but the Sky Crane maneuver was inspired by Sikorsky CH-54B helicopters that routinely airdrop heavy cargo on Earth. The method has advantages over bouncing airbags, which couldn’t have handled Curiosity’s one-ton weight. The landing should be precise and gentle, and because the descent stage flies away after dropping off the rover, there’s no rocket exhaust to contaminate the arrival site, as happens with conventional landers. The journey to Mars takes nine months, but the final, stomach-churning landing sequence, scheduled for August 5, 2012, takes less than a minute. Stay tuned.