When a global storm overtook Mars, NASA got a view of the chaos thanks to a plucky little actuator.
Over the summer, the biggest news on the Martian surface was the massive dust storm. Growing to eventually cover the entire planet, the storm presented a major challenge to NASA’s ongoing exploration of Mars. A new look at the storm’s events show NASA’s Curiosity rover relying on an unexpected source: a tiny actuator which was able to keep it powered and functioning through the worst of the dust.
Curiosity landed on Mars on August 6, 2012 and has been roaming the planet ever since. Alongside NASA’s Opportunity rover, it is one of two artificial objects on Mars that are still transmitting data back to Earth. Around the size of a four door sedan, it has been successful in its goals: before the storm hit this year, it had discovered organic compounds containing carbon — a building block of life.
However, the storm was rising quickly on the planet. On May 30, the Mars Reconnaissance Orbiter (MRO), a satellite orbiting the planet, detected dust accumulating in the atmosphere near where the Opportunity rover was operating. On June 5, on the other side of the planet in the Gale Carter, Curiosity was detecting something similar: the dust storm was rapidly growing. A few days later on June 8, the solar-powered Opportunity rover would be knocked out of commission by the dust.
NASA was clued into the new and changing conditions through an obscure part on Curiosity: a motor which, according to NASA’s press release, “powers a lid to a funnel that takes in samples of powdered Martian rock dropped in by Curiosity’s drill.” Curiosity has a chemistry lab on board that it uses to remotely analyze powdered rock for NASA. And unlike Opportunity, Curiosity is powered by a plutonium generator unbothered by the dust.
“All my charts showed the dust storm effect on the actuator because it’s exposed; it’s sitting out there on the rover deck,” says Benito Prats, a Goddard electromechanical engineer in the press release. “All of a sudden, I saw the daytime temperature drop really quickly.”
The actuator was showing temperatures falling during the day and rising at night, each one outside of normal parameters. These are classic dust storm patterns, with the dust clouding the sun during the day and warming the surface at night.
With a close eye on the surface temperatures, Prats was able to predict where the storm was going. Understanding the exact temperatures, combined with an historic knowledge of Martian storms, allowed him to make an estimate.
“At sol 2125 (July 28), I noticed a linear trend,” he says. “So I said OK, I can predict that sol 2180 (September 23) is going to be when we’re going to get out of the dust storm and the temperature will return back to normal, though I later updated that to sol 2175 (September 18).”
As it would turn out, Prats was right. Things started to settle around the 18th just as predicted. Martian dust storms are still a major unknown for scientists, who are unable to predict them with the same accuracy as they can the rest of Martian weather. Curiosity’s on-the-ground data gave scientists like Prats a distinct edge.
Sadly, Curiosity isn’t out of the woods yet. Mars is a tough place to be, global dust storm or not. Curiosity is experiencing some sort of computer glitch at the moment. Until that problem gets sorted out, it won’t be able to send any further data back home.