Thirteen years after NASA's Curiosity rover landed in the vast Gale Crater on Mars with a spectacular maneuver known as the "sky crane," this tireless robotic explorer shows no signs of slowing down. In fact, engineers at NASA's Jet Propulsion Laboratory (JPL) have designed and implemented a series of software upgrades that allow it to work more productively than ever. With new skills, including greater autonomy and the ability to perform multiple tasks simultaneously, Curiosity is ready to make the most of every precious watt of energy as it continues to unravel the key mystery of the Red Planet: how a world once covered in lakes and rivers turned into the cold, dry desert we know today.

The mission is currently in a crucial phase, exploring the foothills of Mount Sharp (Aeolis Mons), a colossal mountain about 5 kilometers high that rises from the center of Gale Crater. The rover recently rolled into a geologically extremely interesting region full of so-called "boxwork" formations. These unusual, hardened network-like structures stretch for miles and look like petrified honeycombs. Scientists believe they were formed by the action of groundwater billions of years ago. Mineral-rich water penetrated through cracks in the rocks, depositing minerals that eventually created these solid ridges. Later, the softer surrounding rock eroded under the influence of wind, leaving behind only the more resistant mineral veins. Analysis of these formations could provide key insights into whether microbial life could have existed in Mars's subsurface biosphere, potentially extending the planet's period of habitability deep into the era when its surface was becoming increasingly dry and inhospitable.

The Heart of the Mission - An Indefatigable Power Source

This complex detective work on another planet requires enormous amounts of energy. In addition to driving over inhospitable terrain and using its sophisticated robotic arm to study rocks and cliffs, Curiosity must also power its radio for communication with Earth, numerous cameras, and a suite of ten scientific instruments. On top of all that, energy is also consumed by multiple heaters that maintain the optimal operating temperature of sensitive electronics, mechanical parts, and instruments in the extreme Martian conditions, where temperatures can vary by more than 100 degrees Celsius between day and night.

Unlike its predecessors such as the Spirit and Opportunity rovers or the InSight lander, which relied on solar panels to charge their batteries, Curiosity uses a nuclear power source. That technology carries the risk of dust storms covering the panels or simply not having enough sunlight to operate. Curiosity and its younger "brother," the Perseverance rover, use a Multi-Mission Radioisotope Thermoelectric Generator, better known as an MMRTG. This system works on the principle of heat released by the natural decay of plutonium-238 pellets. This heat is then converted into electrical energy that continuously charges the rover's lithium-ion batteries. The MMRTG provides a stable and reliable source of energy, independent of the time of day or weather conditions, and is known for its longevity – similar systems have been powering the legendary Voyager spacecraft since 1977. However, as plutonium slowly loses its radioactivity over time, the amount of generated heat and, consequently, electrical energy, gradually decreases. This means that over the years, it takes longer and longer to charge the batteries, leaving less available energy for scientific activities each Martian day (sol).

A Revolution in Daily Work: A Rover Learning New Skills

To counteract this natural decline in power, the mission team carefully manages the rover's daily energy budget, taking into account every device that draws power from the batteries. Although all components were extensively tested before launch, only years of operation in the extreme Martian environment – exposure to dust, radiation, and sharp temperature changes – have revealed the specific "quirks" of the complex systems that engineers could not fully predict. "At the beginning of the mission, we were like overly cautious parents," colorfully described Reidar Larsen from JPL, who led the group of engineers responsible for developing the new capabilities. "Now it's as if our 'teenage' rover has matured and we trust it to take on more responsibility. As a child, you do one thing at a time, but as you grow up, you learn to perform multiple tasks simultaneously."

A typical workday for Curiosity begins with engineers from Earth sending a list of tasks for the rover to complete one after another, before it ends the day and goes to "sleep" to recharge its batteries. Back in 2021, the team began to study whether two or three tasks could be safely combined, thereby reducing the rover's total activity time. For example, Curiosity regularly sends data and images to an orbiter passing overhead, which then relays that data to Earth. The question arose: can the rover communicate with the orbiter while simultaneously driving, moving its robotic arm, or taking photos? Consolidating tasks would shorten the daily plan, requiring less time for heaters to run and for instruments to be on standby, resulting in significant energy savings. Tests have shown that Curiosity can perform this safely, and all of these combined operations have now been successfully demonstrated on Mars.

Another clever trick involves giving the rover the autonomy to decide to go to "sleep" on its own if it finishes its tasks earlier than planned. Engineers always add a certain time buffer to their activity duration estimates in case of unforeseen difficulties. Now, if Curiosity completes all its tasks before the allotted time expires, it will automatically switch to a sleep state. Allowing the rover to manage its own rest means that less time is needed to charge the batteries before the start of the next day. Even actions that shorten an individual activity by just 10 or 20 minutes add up over the long term and significantly contribute to maximizing the lifespan of the MMRTG, ensuring more science and exploration in the years to come.

Adaptation is the Key to Survival on Mars

These are not the first adjustments Curiosity has undergone. The team has implemented numerous new capabilities over the years in response to challenges. Several mechanical problems with the drill on the robotic arm required a complete redesign of how the rover collects samples of powdered rock. Driving capabilities have also been improved with software updates. When the color filter wheel got stuck on one of the two cameras (Mastcam) on the rover's movable "head," the team developed an innovative solution that still allows it to capture beautiful color panoramas.

JPL also developed a special algorithm to reduce the wear and tear on Curiosity's wheels, which have suffered damage from sharp rocks. A photograph taken at the end of July 2025 shows a strangely shaped rock, resembling a coral, as a testament to the billions of years of wind erosion that shaped the landscape. Although engineers closely monitor every new damage to the wheels, they are not concerned. After traveling more than 35 kilometers and extensive exploration, it is clear that, despite some punctured parts, the wheels have many more years of travel ahead of them. In the worst-case scenario, Curiosity could even shed a damaged part of the wheel "tread" and continue moving on the remaining, undamaged part. All these measures together ensure that Curiosity remains as busy and productive as ever, continuing its historic mission to uncover the secrets of the Red Planet.