Despite signs of wear and tear, the intrepid spacecraft is about to begin an exciting new chapter of its mission as it climbs a Martian mountain.
Ten years ago today, a jetpack lowered NASA’s Curiosity rover onto the Red Planet, launching the SUV-sized discovery after evidence that billions of years ago Mars had the conditions needed to support microscopic life.
Since then, Curiosity has driven nearly 18 miles (29 kilometers) and climbed 2,050 feet (625 meters) as it explores Gale Crater and the base of Mount Sharp within it. The rover has analyzed 41 rock and soil samples, based on a range of scientific instruments, to find out what they reveal about Earth’s rocky siblings. And that has pushed a team of engineers to find ways to minimize wear and tear and keep the rover running: In fact, Curiosity’s mission was recently extended for another three years so it can continue among NASA’s fleet of important astrobiology missions.
An abundance of science
It has been a busy decade. Curiosity has been studying the Red Planet’s sky, taking pictures of shimmering clouds and drifting moons. The rover’s radiation sensor allows scientists to measure the amount of high-energy radiation future astronauts will be exposed to on the Martian surface, helping NASA figure out how to keep them safe.
But most importantly, Curiosity has determined that liquid water as well as the chemical building blocks and nutrients needed to support life were present for at least tens of millions of years in Gale Crater. The crater once held a lake, whose size waxed and waned 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, one thought to have formed as water dried up, leaving behind salty minerals called sulfates.
“We see evidence of dramatic changes in the ancient Martian climate,” said Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “The question now is whether the habitable conditions that 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 striking progress up the mountain. Back in 2015, the team took a “postcard” photo of distant Baker. One spot in the image is a Curiosity-sized boulder nicknamed “Ilha Novo Destino” — and nearly seven years later, the rover rolled past it last month on its way to the sulfate-rich region.
The team plans to spend the next few years exploring the sulfate-rich area. Within it, they have targets in mind such as the Gediz Vallis channel, which may have formed during a flood late in Mount Sharp’s history, and large cemented fissures that show the effects of groundwater higher up the mountain.
How to keep a rover rolling
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 every crack in the wheels, test every line of computer code before sending it into space, and drill endless rock samples into JPL’s Mars Yard to ensure Curiosity can safely do the same.
“Once you land on Mars, everything you do is based on the fact that there’s no one around to repair it for 100 million miles,” said Andy Mishkin, Curiosity’s acting project manager at JPL. “It’s about making intelligent 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 offline for more than a year as engineers redesigned its use to be more like a handheld drill. Recently, a set of braking mechanisms that allow the robot arm to move or remain in place stopped working. Although the arm has been working as usual since engineers inserted a set of spares, the team has also learned to drill more gently to preserve the new brakes.
To minimize damage to the wheels, engineers keep an eye out for treacherous spots like the knife-edged “gator-back” terrain they recently discovered, and they developed a traction control algorithm to help.
The team has taken a similar approach to dealing with the rover’s slowly waning power. Curiosity relies on a long-lasting nuclear-powered battery instead of solar panels to keep rolling. As the plutonium pellets in the battery decay, they generate heat that the rover converts into power. Because of the pellet’s gradual decay, the rover cannot do as much in a day as it did in the first year.
Mishkin said the team continues to budget how much energy the rover uses each day and has figured out what activities can be done in parallel to optimize the energy available to the rover. “Curiosity is definitely doing more multitasking where it’s safe to do so,” Mishkin added.
Through careful planning and technical hacks, the team has every expectation that the smart rover still has many 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.
For more on Curiosity, visit:
http://mars.nasa.gov/msl and https://www.nasa.gov/mission_pages/msl/index.html
News Media contacts
Jet Propulsion Laboratory, Pasadena, California.
Karen Fox / Alana Johnson
NASA Headquarters, Washington
301-286-6284 / 202-358-1501
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