August 3, 2012
JPL prepares for ‘7 minutes of terror’
The atmosphere at Caltech’s Jet Propulsion Laboratory (JPL) will be a mixture of fear and anxiety on Sunday, Aug. 5, as its engineers and scientists hope to make history with the successful landing of the Curiosity rover on Mars.
The landing, described in the viral video, “7 Minutes of Terror,” is a risky descent into the Martian atmosphere that will require the lander to go from 13,000 mph to an almost dead stop in seven minutes—all without direct help from JPL.
“Sunday is the big day. The ‘7 Minutes of Terror’ video is not far off from how the landing will look. This really is the scariest part of the mission. However, we are all looking forward to it and [are] very excited,” said Richard Kornfeld, deputy lead for the mission’s entry, descent and landing (EDL) phase.
The Curiosity rover is NASA’s latest Mars Science Laboratory (MSL) mission, part of NASA’s Mars Exploration Program, a long-term effort devoted to the robotic exploration of Mars. Similar in design to past rovers Spirit and Opportunity, Curiosity is about twice as long and nearly five times as heavy — about the size of a Mini Cooper. At $2.5 billion, it’s the most expensive Mars mission to date.
Launched from Cape Canaveral on Nov. 26, 2011, Curiosity has traveled 352 million miles over more than 8 months. The rover’s mission is to determine whether conditions on Mars were once favorable for microbes.
The world will not know Curiosity’s fate until about 21 minutes after the rover first begins its landing at 10:31 p.m. PST. Once it enters Mars’ atmosphere, it will take seven minutes for the rover to land, but 14 minutes for the data to travel to Earth.
Following entry into the Martian atmosphere, which is 100 times thinner than Earth’s, the spacecraft will slow from 13,000 mph to 1,000 mph. With the release of a 100-pound supersonic parachute, the craft is expected to then drop its heat shield and slow to 200 mph. A descent stage, with the rover attached, will then separate and fire its rockets to navigate away from the spacecraft. Once hovering over Gale Crater, the descent stage will lower the rover via a sky-crane maneuver, cut its cords and then fly away.
A video camera on board Curiosity is expected to record several minutes of the landing.
[Story continues after the jump]
“We are all going to be very nervous on Sunday, but also very optimistic. We’ve done every test we can imagine over the past years, but there are no guarantees. And, because landing on Mars doesn’t have a good track record, there will be a sense of nervousness in the air,” said Jonathan Grinblat, avionics subsystem Lead for cruise, approach and EDL operations.
Past mission failures are on the minds of JPL’s engineers.
In 1999, NASA lost its $125 million Mars Climate Orbiter when the craft entered too low of an orbit. An investigation traced the problem to a Lockheed Martin engineering team’s use of English units rather than standard metric units when writing part of the probe’s software.
Grinblat said that failed attempts helped with the Curiosity landing.
“The unsuccessful missions are definitely in the back of our minds. But we learned from those attempts what types of mistakes we can anticipate. It’s helping us to think outside of the box,” he said. “The hardest part is really trying to anticipate things we can’t even think of. We have to plan for the unknown. We have to make the rover robust enough to deal with things we can’t even imagine. And that’s the hardest part, being able to make the rover autonomously deal with the potential failure modes of landing on Mars and be able to recover.”
If successful, the rover will explore the planet for at least 687 Earth days (1 Martian year). During that time it will study the climate and geology of Mars, which will help NASA plan for a future manned mission to Mars.
“If everything goes well, it will be a pretty exciting science mission. On Monday morning, the science teams will take over and it switches to exploration and discovery mode,” said Robert Zimmerman, power systems engineer. “In terms of the future, it is hard to say what scientific data we are going to find and what we are going to be able to do with it. But one way or another, we learn a whole lot from this landing.”
Curiosity’s landing will be live-streamed on several Web sites and can be viewed on the NASA TV Media Channel. The Griffith Observatory will be hosting live coverage of the event with commentary and questions Sunday night from 9 p.m. to midnight.