For a spacecraft that’s traveled millions of kilometers across space and driven on the surface of Mars, Curiosity is holding up pretty darned well. That’s the assessment from the operations team at NASA Jet Propulsion Laboratory. This week they celebrated ten years of the rover’s exploration across one of the more forbidding terrains in the solar system.
Curiosity landed on the Red Planet on August 5th, 2012. As it made its way down to the surface, the entire world waited for news of a safe landing. That included a dangerous seven-minute ride from Mars orbit to the surface. Ever since, the rover has worked to deliver a “YES!” answer to the question: could Mars have supported ancient life?
Curiosity Explores Gale Crater and Looks for Water
Curiosity’s been busy over the past decade. It’s in remarkably good shape, considering what it’s facing on the planet. There are extreme temperatures, rough terrain, high radiation levels, and dust storms. Through all that, it continues to send back “webcam on Mars” views of the terrain and rocks of Gale Crater and Mount Sharp. Not only that, it’s been providing a look at the sky, sunsets, clouds, and even glimpses of Phobos and Deimos. The rover has analyzed 41 rock and soil samples from its travels around the crater and up the mountain slopes. The engineering team has used that meandering trip to learn more about the wear and tear on the rover and worked to minimize the damage so that the mission can continue for another three eventful years. And, much more.
Its most crucial job is to show the history of water on Mars. Curiosity has shown that Mars had liquid water, plus the chemical building blocks and nutrients that life needs in order to exist. Gale Crater has been a spectacularly wonderful place to look since it once held a lake. Each time the lake subsided and then filled again, it left evidence on the slopes of Mount Sharp. And, Curiosity is there to read that record for us. As it makes its way up Sharp, it will soon be showing scientists more places where water dried out, leaving behind salty mineral deposits.
“We’re seeing 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 up to now persisted through these changes. Did they disappear, never to return, or did they come and go over millions of years?”
Keeping Curiosity Alive
The Curiosity mission demonstrates once again just how well-engineered these Mars surface missions can be. They’re built strong to last, and hundreds of dedicated engineers keep them going. For Curiosity, they monitor everything about the rover, catalog cracks in the wheels, and test-drill into rock samples here on Earth before Curiosity does the same on Mars. Computer engineers constantly test the code before sending commands to the rover, and watch carefully as the rover goes through its paces.
“As soon as 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 all about making intelligent use of what’s already on your rover.”
Curiosity’s robotic hardware usage and drilling processes, for example, have been reinvented multiple times since landing. More recently, a set of braking mechanisms on the robotic arm stopped working. Although the arm has been operating as usual since engineers engaged 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 that could harm the rover. To deal with these areas, they developed a traction-control algorithm to help.
The team has taken a similar approach to manage the rover’s slowly diminishing power. Curiosity relies on a long-lived nuclear-powered battery rather than solar panels to keep on rolling. Because of the gradual decay of nuclear fuel, the rover can’t do quite as much in a day as it did during its first year.
Curiosity’s Immediate Future
So, what’s up next for Curiosity? Everyone hopes it will stay curious. It should spend quite a bit of time over the next few years checking out sulfate-rich areas in Gale Crater. They also have their eyes on a flood channel called Gediz Vallis. It may be an ancient flood-created feature and could tell more tales about water on Mars. Through careful planning and engineering hacks, the team expects this hardy rover to be exploring for years to come.