WASHINGTON – On Aug. 5, 2012, after completing a nine-month, 354 million mile journey, mission controllers at NASA’s Jet Propulsion Laboratory will attempt to break the fall of a rover-carrying spacecraft traveling at about 13,000 miles per hour to zero and set down the rover in a Martian crater.
The landing sequence for the Mars rover Curiosity is called the “Seven Minutes of Terror.”
For the first time, NASA will use an untried descent and landing technique to lower Curiosity to the surface near Gale Crater using a sky crane. The entire landing sequence will be controlled by computers relying about 500,000 lines of code that will control no less than 76 rockets and thrusters.Mission managers won’t know whether it worked for 14 minutes, the time it takes a signal from Mars to travel back to Earth.
To the casual observer, using a sky crane to land on Mars may look crazy, but “it is the result of reasoned engineering thought,” argues JPL’s Adam Steltzner, chief engineer for the Mars Science Laboratory.
“If any one thing doesn’t work just right, it’s game over,” adds JPL’s Tom Rivellini.
Previous Martian landings used what amounted to air bags to break the fall of rovers. Curiosity is too big and heavy – about the size of an SUV – to use that landing method. Hence, JPL engineers came up with a system of braking rockets, a huge parachute and the sky crane to slow Curiosity’s fiery entry into the faint Martian atmosphere and gently deposit it in Gale Crater, which is suspected of harboring signs of Martian life.
The JPL engineers and scientists are sticking their necks way out on this mission, and that’s precisely the type of technological risk-taking that is needed to explore the solar system with our marvelous machines.
As we know, it landed successfully! CONGRATULATIONS TO EVERYONE AT JPL! I said it before and I'll say it again, you guys should have a holiday named after you and a ticket-tape parade! I can't begin to express how happy I am for you all! Congrats! Congrats! Congrats!
From July 16 NASA press conference:
"We expect to get Curiosity safely onto the ground, but there is no guarantee. The risks are real," said Pete Theisinger, the Jet Propulsion Laboratory's Mars Science Laboratory project manager.
A reader asked earlier whether NASA had calculated the chances for successfully landing Curiosity on Mars in August. Here is the full response to our question from a spokesman at the Jet Propulsion Laboratory, which is subject to different interpretations:
"No. Important risks are the unknowns, which resist calculating."
Very nice video. At least I can appreciate why MSL went way over budget. The first question that came to my mind - why did Curiosity have to be so big and heavy as to require such an elaborate landing method? When I think of the best value for our space dollar, I think of Spirit and Opportunity, which lasted years beyond their required mission life.
We thought the video was was very relevant to our engineering audience because the JPL engineers were sticking their necks out and trying to come up with a solution. It's highly likely this won't work, but these guys are being honest and their mistakes will be public for all the world to see. That's the way we've always done it, and no one can touch us in terms of space exploration.
Very interesting article and discussion...but I am unable to enjoy the video. For whatever reason, not all of the controls are visible. I wanted to watch full-screen, so I clicked around, but no go. Now I get no sound.
I am using Firefox 13.0.1 up-to-date. I also tried IE9, but results are the same (no full-screen button visible, no sound).
Can this be fixed? Or can someone provide a link to somewhere else I can see the video directly?
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.