Sample cache, seven payloads to fly on Mars rover
BY STEPHEN CLARK
Posted: August 3, 2014
NASA's next Mars rover will identify, gather and store rock core samples for possible pickup by future robots or astronauts, continue the quest for evidence of past life, and likely employ redesigned wheels to avoid the dings and holes now afflicting the Curiosity rover on the red planet.
Space agency officials announced Thursday the seven instruments selected to fly to Mars aboard the rover, which is set for launch in 2020.
The Mars 2020 mission will use the entry, descent and landing system demonstrated on Curiosity when it arrived on Mars in 2012, along with the same rover chassis. Engineers will tweak some of the design to account for parts obsolescence, improve landing accuracy, and will likely change materials used for the rover's wheels, officials said.
John Grunsfeld, head of NASA's science division, said NASA's target budget for the Mars 2020 mission is $1.9 billion, less than the $2.5 billion spent on Curiosity.
"We've built up this incredible portrait of Mars as this potentially habitable world," said Ellen Stofan, NASA's chief scientist. "[Mars] 2020 will take us the next step, making more sophisticated measurements to really try to understand this fundamental question that drives so much of what we do at NASA: Are we alone in our solar system [and] in our universe?"
The instruments selected for the Mars 2020 rover include contributions from scientists and institutions in Norway, Spain and France.
Here is a list of the rover's payloads from NASA:
NASA selected the seven instruments from more than 50 proposals by U.S. and international science teams, according to Jim Green, director of the agency's planetary science programs.
Grunsfeld said the rover's payload is expected to cost about $130 million and weigh about 40 kilograms, or 88 pounds. The mass figure does not include a new drilling system and a cache to house rock core samples for potential retrieval by a later mission.
Curiosity carries a larger $180 million, 165-pound sensor suite, but NASA officials said the 2020 rover will pack a bigger scientific punch than Curiosity.
"I consider this a real improvement of all the instruments that are on-board, and also the potential science this rover can do is more than what Curiosity can do right now," said Michael Meyer, NASA's chief scientist for Mars exploration.
According to Grunsfeld, the Mars 2020 mission will feature instruments to do enhanced imaging, improved mineralogy mapping, and collect measurements never before attempted on the Martian surface.
"This really is a souped-up instrument suite compared to Curiosity, and the two together, especially if we get to look at two different, diverse sites on Mars, may be completely transformative," Grunsfeld said.
The MOXIE payload, sponsored by NASA's human exploration and operations directorate, will attempt to extract oxygen from the Martian atmosphere. Officials said MOXIE will be a pathfinder for future missions, when astronauts could utilize the Martian environment to produce rocket fuel, breathable air, water and other resources.
"We'll get a chance to look at things like in situ resource utilization, [where] we look at the ability to use some of the resources on Mars to see if they actually have applications for human missions in the future," said Bill Gerstenmaier, associate administrator for NASA's human exploration and operations division. "Those will dramatically change how we plan and get ready for those missions."
The Martian oxygen generator on the Mars 2020 rover is the first of its kind to go to the red planet.
Michael Hecht, principal investigator for MOXIE from the Massachusetts Institute of Technology, said the instrument will produce up to 20 grams of oxygen per hour through a process known as electrolysis.
"This is essentially a fuel cell run in reverse," Hecht said. "We start with CO2, which is usually a product of fuel cells. We put in electricity instead of getting electriciy out, and we get out oxygen and [carbon monoxide]."
The Mastcam-Z camera suite on the Mars 2020 rover will capture the sharpest views yet of the planet's rust-colored terrain. The camera will collect stereo images, giving scientists, mission engineers and the public a look at Mars is if they were there.
Several of the instruments, including Mastcam-Z, the Supercam sensors for mineral and organic molecule detections, and the MEDA weather station, are upgraded versions of sensors flown on Curiosity.
Other payloads like the MOXIE oxygen generator and the Norwegian-led subsurface sounding radar are flying to Mars for the first time.
Svein-Erik Hamran, lead scientist on the radar from the Forsvarets Forskning Institute in Norway, said his payload "can determine what kind of geology the rover is driving through."
"The radar is very good at detecting and following layers, so it can detect different outcrops and show if they are in the same geological unit," Hamran said. "The radar can also see other interesting structures beneath the ground, such as possible ground ice or ground water."
Engineers are still completing development of the rover's sample cache system.
"The basic idea is that we will take a core sample that is about the dimension of a piece of chalk for writing on a chalkboard," said Ken Farley, Mars 2020 project scientist at NASA's Jet Propulsion Laboratory. "The core will be inserted in a tube that fits tightly around it, and that tube will be sealed to prevent gases from being lost."
The rover's cache is the first step required to return Martian samples to Earth. The sample storage capability was the top recommendation by the National Research Council's last decadal survey in planetary science, which prioritizes missions to visit destinations in the solar system.
The second priority in the council's 2011 survey report was a mission to study Jupiter's icy moon Europa.
The Mars 2020 rover will store approximately 30 sealed rock core samples, officials said. The samples should be preserved for at least 20 years, according to Meyer.
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