WASHINGTON — NASA’s plan to simplify the Mars 2020 rover’s mission by letting the Curiosity-clone dig up and drop surface samples instead of babysitting them until a fetch rover arrives is starting to win hearts and minds within the agency, NASA’s Mars czar said in a June 25 interview.
When Mars 2020 was conceived in 2012, NASA engineers and scientists thought the rover would drill sample cores from the martian surface, tuck them away in tubes, and tuck the tubes into a collection box to be carted around with the rover like cash in an armored car. In a subsequent mission, Mars 2020’s cache would be transferred to a Mars ascent vehicle that would carry the samples to orbit for return to Earth.
But “about a month ago,” Jim Watzin, the agency’s Mars Exploration Program director, said he approved a plan conceived in a November system concept review to remove the caching box from Mars 2020. Under the new plan, Mars 2020 will collect and tube samples, then leave the tubes in piles wherever the rover’s operations team thinks is best.
“The science community in general has been very receptive,” Watzin said in a June 25 phone interview. “Once they started to ponder the architecture, they saw the flexibility it gives to make decisions to maximize the science during the mission.”
Watzin contends that forcing Mars 2020 to carry samples all across the red planet might make mission planners unduly averse to risk. As the size of the cache grows, Watzin said, the consequences of losing it eventually outweigh the risk of proceeding to another sample spot in an attempt to improve the haul.
On the other hand, periodically thinning the cache until the ground is littered with enough cores to make a fetch-and-return rover scientifically intriguing gives operators flexibility to take greater risks for greater rewards with Mars 2020.
Support for the dig-and-drop approach, which NASA calls “adaptive caching,” snowballed within the agency to the point where Watzin approved it as part of Mars 2020’s baseline design. That means the approach will be carried into a preliminary design review scheduled for December, when a review team will examine the soundness of NASA’s initial design.
Mars 2020 is a crucial step in an eventual Mars sample return campaign the White House has not formally embraced because of the years-long commitment and substantial cost of the endeavor. However, the Obama administration cleared NASA to begin chipping away at the task and, as part of its 2013 budget request, to build the Mars 2020 rover out of spare parts from the Curiosity rover that landed on the red planet in 2012.
Ultimately, NASA’s associate administrator for science, John Grunsfeld, will have to sign off on the Mars 2020 design. The concept will also have to survive both the preliminary design review in December, and a critical design review that will follow it.
While adaptive caching could get the thumbs down during either review, a recently announced Mars 2020 procurement decision lends credence to the idea that the agency is serious, and confident, about the dig-and-ditch approach.
In March, a Pasadena, California, company called Motiv Space Systems got an $11 million cost-plus contract from NASA’s Jet Propulsion Laboratory to build Mars 2020’s robotic arm.
The company’s orders? Use the robotic arm from Curiosity as a jumping-off point.
“Right now, the Mars 2020 robotic arm is very similar to the Curiosity robotic arm,” said Chris Thayer, president and chief executive of Motiv Space Systems.
That is significant because, as Ken Farley, Mars 2020 project scientist at NASA’s Jet Propulsion Laboratory, told the Mars Exploration Program Analysis Group earlier this year, forcing Mars 2020 to slot sample cores into a storage canister that would be picked up by a subsequent mission would mean fitting the rover with a more massive and capable arm than Curiosity’s.
Still, JPL gave Motiv a cost-plus deal, meaning the center is free to levy additional design requirements and pay the contractor to meet them.
Motiv, founded in 2014 by a group of former MDA Corp. veterans, has about half a dozen active contracts, Thayer said. Most are space related, and most of those are for either JPL or the Goddard Space Flight Center in Greenbelt, Maryland — NASA centers known for robotics programs.
As for the caching system itself, which will consist of what Watzin called “pristine” tubes to store martian surface cores, procurement decisions will wait at least until after the preliminary design review in December.