Despite signs of wear and tear, the intrepid spacecraft is about to begin an exciting new chapter of its mission as it scales a Martian mountain.
Ten years ago, a jetpack lowered NASA’s Curiosity rover onto the Red Planet, beginning the SUV-sized rover’s search for evidence that, billions of years ago, Mars had the conditions necessary to support microscopic life.
Since then, Curiosity has traveled nearly 18 miles (29 kilometers) and climbed 2,050 feet (625 meters) while exploring Gale Crater and the foothills of Mount Sharp within it. The rover has analyzed 41 rock and soil samples, drawing on a suite of scientific instruments to learn what they reveal about Earth’s rocky brother. And it has pushed a team of engineers to come up with ways to minimize wear and tear and keep the rover going: in fact, Curiosity’s mission was recently extended for another three yearsallowing it to continue among NASA’s fleet of important astrobiological missions.
A generosity of science
It’s been a busy decade. Curiosity has studied the skies of the Red Planet, capturing images of bright clouds Y drifting moons. The rover’s radiation sensor allows scientists to measure the amount of high-energy radiation. to which future astronauts would be exposed on the Martian surfacehelping NASA figure out how to keep them safe.
But most importantly, Curiosity has determined that liquid water, as well as the chemicals and nutrients necessary to support life, were present for at least tens of millions of years in Gale Crater. The crater once contained a lake, the size of which increased and decreased over time. Each layer higher up on Mount Sharp serves as a record of a more recent era of the Martian environment.
Now the intrepid rover is driving through a canyon that marks the transition to a new region, thought to have formed when the water was drying up, leaving behind salty minerals called sulfates.
“We’re seeing evidence of dramatic changes in the ancient Martian climate,” said Ashwin Vasavada, Curiosity project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “The question now is whether the habitable conditions Curiosity has found so far persisted through these changes. Did they disappear never to return, or did they come and go over millions of years?
Curiosity has made amazing progress up the mountain. In 2015, the team captured a picture of “postcard” from distant hills. A mere speck within that image is a rock the size of a curiosity nicknamed “Ilha Novo Destino” – and, nearly seven years later, the rover passed it last month en route to the sulfate region.
The team plans to spend the next few years exploring the sulfate-rich area. Within it, they have targets in mind like the Gediz Vallis Canal, which may have formed during a flood at the end of Mount Sharp’s story, and large cemented fractures showing the effects of groundwater further up the mountain.
How to keep a rover running
What is Curiosity’s secret to maintaining an active lifestyle at the ripe old age of 10? A team of hundreds of dedicated engineers, of course, working both in person at JPL and remotely from home.
They catalog each and every crack in the wheels, test every line of computer code before it’s beamed into space, and drill endless rock samples at JPL’s Mars Yard, ensuring Curiosity can safely do the same.
“As soon as you land on Mars, everything you do is based on the fact that there’s no one around to fix it for 100 million miles,” said Andy Mishkin, interim project manager for Curiosity at JPL. “It’s about making smart use of what’s already on your rover.”
Curiosity’s robotic drilling process, for example, has been reinvented several times since landing. At one point the drill was out of service for over a year as engineers redesigned its use be more like a hand drill. More recently, a set of braking mechanisms that allow the robotic arm to move or stay in place stopped working. Although the arm has been working as usual since engineers contracted for a spare set, the team also learned to drill more carefully to preserve the new brakes.
The team has taken a similar approach to managing the rover’s slowly declining power. Curiosity builds on a long life nuclear powered battery instead of solar panels to keep rolling. As the plutonium pellets in the battery break down, they generate heat that the rover converts to energy. Due to the gradual breakdown of the pellets, the rover cannot do as much in one day as it did during its first year.
Mishkin said the team continues to budget for how much power the rover uses each day and has figured out what activities can be done in parallel to optimize the power available to the rover. “Curiosity is definitely doing more multitasking where it’s safe to do so,” Mishkin added.
Through careful planning and engineering tricks, the team has every hope that the plucky rover still has years of exploration ahead of it.
More about the mission
JPL, a division of Caltech in Pasadena, built Curiosity for NASA and is leading the mission on behalf of the agency’s Science Mission Directorate in Washington.
News Press Contacts
Jet Propulsion Laboratory, Pasadena, California.