Space Grant Consortium’s Yingst to play critical role in Mars rover mission

The buzz is building over an early August landing planned for NASA’s most advanced planetary rover — and R. Aileen Yingst, director of the Wisconsin Space Grant Consortium, headquartered at UW-Green Bay, is one of the scientists at the heart of the operation.

R. Aileen Yingst

R. Aileen Yingst

The Curiosity rover is scheduled to land in the early morning hours (local time) Monday, Aug. 6 beside a Martian mountain to begin two years of unprecedented scientific detective work. Its planned landing is so complex that it’s been dubbed the “seven minutes of terror,” and Yingst will have a critical role in the daring endeavor.

“This mission is the unmanned equivalent of Apollo in terms of how tremendously difficult it has been, is and will be,” said Yingst, who left July 29 for NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “I tell my kids you have to dare big to accomplish big — and that’s what we’re doing here.”

She isn’t kidding. To achieve the precision needed for landing safely inside Gale Crater, the spacecraft will fly like a wing in the upper atmosphere, instead of dropping like a rock. To land the one-ton rover, an airbag method used on previous Mars rovers will not work. Mission engineers at the Jet Propulsion Laboratory (JPL) in Pasadena have designed a “sky crane” method for the final several seconds of the flight. A backpack with retro-rockets controlling descent speed will lower the rover on three nylon cords just before touchdown.

During a critical period lasting only about seven minutes — the aforementioned “seven minutes of terror” — the Mars Science Laboratory spacecraft carrying Curiosity must decelerate from about 13,200 mph (about 5,900 meters per second) to allow the rover to land on the surface at about 1.7 mph (three-fourths of a meter per second). Curiosity is scheduled to land at approximately 12:31 a.m. local time Aug. 6.

“Those seven minutes are the most challenging part of this entire mission,” said Pete Theisinger, the mission’s project manager at JPL. “For the landing to succeed, hundreds of events will need to go right, many with split-second timing and all controlled autonomously by the spacecraft. We’ve done all we can think of to succeed. We expect to get Curiosity safely onto the ground, but there is no guarantee. The risks are real.”

If Curiosity’s landing is successful, Yingst could be in Pasadena for several months in her role as deputy principal investigator for one camera on the mission. Her instrument, the Mars Handlens Imager (MAHLI) will return pictures of the martian surface at 12 µm/pixel (for comparison, a human hair is about 80 microns across). At this scale, Yingst  said, the surfaces of individual minerals, or even sand grains, can be seen. The MAHLI camera will be critical in determining what rocks are made of at the Mars Science Laboratory landing site, where Yingst and her colleagues expect the rocks will be sedimentary (broken up bits of other rocks, transported there by wind, water or volcanic activity).

And while Yingst will be across the country for this unprecedented event, she’s also bringing a bit of Wisconsin to mission control. Yingst’s camera is mounted on the instrument package at the end of the turret (the “arm”). The turret is informally known by some engineers as the “cheesehead.” (Yingst, for the record, is a Packers fan).

During the initial weeks after the actual landing, JPL mission controllers will put the rover through a series of checkouts and activities to characterize its performance on Mars, while gradually ramping up scientific investigations. Curiosity then will begin investigating whether an area with a wet history inside Mars’ Gale Crater ever has offered an environment favorable for microbial life.

Curiosity will use tools on a robotic arm to deliver samples from Martian rocks and soils into laboratory instruments inside the rover that can reveal chemical and mineral composition. A laser instrument will use its beam to induce a spark on a target and read the spark’s spectrum of light to identify chemical elements in the target.

Other instruments on the car-sized rover will examine the surrounding environment from a distance or by direct touch with the arm. The rover will check for the basic chemical ingredients for life and for evidence about energy available for life. It also will assess factors that could be hazardous for life, such as the radiation environment.

The chosen landing site is beside a mountain informally called Mount Sharp. The mission’s prime destination lies on the slope of the mountain. Driving there from the landing site may take many months.

“Be patient about the drive. It will be well worth the wait and we are apt to find some targets of interest on the way,” said John Grotzinger, MSL project scientist at the California Institute of Technology in Pasadena. “When we get to the lower layers in Mount Sharp, we’ll read them like chapters in a book about changing environmental conditions when Mars was wetter than it is today.”

Mars Science Laboratory is a project of NASA’s Science Mission Directorate. The mission is managed by JPL. Curiosity was designed, developed and assembled at JPL, a division of the California Institute of Technology in Pasadena.

You can follow the mission on Facebook and on Twitter. Information about the mission, along with the new video game and other education-related tools, is available online, here and here. You can also watch the “Seven Minutes of Terror” video.


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