For Safe Landings On Two Planets
The 2013 National Air and Space Museum Trophy Winners.
- By The Editors
- Air & Space magazine, April 2013
NASA / JPL-CalTech
The National Air and Space Museum trophy is an annual award recognizing both past and present achievements in the management or execution of a scientific or technological project, a distinguished career in air and space technology, or a significant contribution in chronicling the history of air and space technology. For outstanding current achievement, this year the Museum recognizes the Mars Science Laboratory Entry, Descent and Landing team, led by Adam Steltzner, which brought the Curiosity rover to a safe landing on Mars last August. For lifetime achievement, the Museum honors Joe Sutter, the chief project engineer for the world’s first wide-body airliner, the Boeing 747.
Mars Science Laboratory Entry, Descent and Landing Team
Adam Steltzner led the 40-member team at NASA’s Jet Propulsion Laboratory that developed the Sky Crane landing system for the Mars Science Laboratory Curiosity rover. The team began work on the entry, descent, and landing procedures and design in 2003; the rover touched down on Mars on August 6, 2012.
How was the Sky Crane developed?
The Sky Crane came into existence over several years, in fits and starts, with several contributions from different people. Its final germ happened in a great brainstorming session in the fall of 2003. In 1999-2000, after the loss of the Mars Polar Lander, there were some teams working to try and understand how we would land the rover for the Mars Sample Return, which then was on the books for 2003 or 2005. It had been planned to use a legged lander, like the one that had failed on MPL, but the mishap investigation helped underscore some of the weaknesses of a legged lander system. So the teams were looking at [other] ways of delivering a large lander.
There were several ideas out there, one of which was called Rover on a Rope. If you were to imagine the Mars Pathfinder or Mars Exploration Rover landing system and just strip away the airbags and have the rover naked at the end of the bridle, it was akin to that. But that idea was discarded by the teams as being too unstable and unusable.
The method that was chosen was something called the Pallet Lander, in which you take the legged lander and you give it six legs instead of three and you spread them out very flat to make the thing very stable. So the MSL went ahead with the Pallet Lander. Unfortunately, we were struggling with the Pallet Lander [because it was too unstable]. We couldn’t use airbags or legged landers, but the experiences from them were there for us to understand how to innovate. We were forced into innovating by the laws of physics, but it was the experience of the past that allowed us to know how to make a system that was as successful as it was.
So in the fall of 2003, we got [about a dozen engineers] together for a big brainstorming session and threw out on the table everything that we’d previously considered, whether we’d rejected it or not. And we tried to work our way through to get past this logjam we were in with the Pallet. It was out of that brainstorming session and some modifications of the ideas from Rover on a Rope but with some very important additions, like leaving the parachute behind when the two bodies [the rover and its rocket-powered descent stage] are still attached, and waiting until the last minute in vertical flight to do the rover deployment. Those ideas really were the germs that made the Sky Crane happen.
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