Inside the seven-hour shift that tells Curiosity what to do on Mars
Every working day, a few dozen people meet at NASA’s Jet Propulsion Laboratory in Pasadena. They get about seven hours to decide what a car-sized robot will do next. That robot, the Curiosity rover, sits more than 100 million miles away on Mars. Ashwin R. Vasavada is the project scientist for Curiosity, and he described this daily routine himself. His account appeared in The Conversation and was republished by Robohub on September 21, 2026. It is the clearest public look in a while at how a Mars rover really works. Nobody drives it. They plan it.
Vasavada writes that he gets to the Rover Operations Center at 7:30 a.m. Overnight, Curiosity finished its Martian day. It sent its pictures and measurements up to a spacecraft circling Mars, and that spacecraft passed them on to Earth. The shift starts at 8:15 a.m. The team then has three hours to do three things. They check that the rover is healthy, study the new science data, and agree on what to do next. After that, they spend about four more hours turning those choices into commands. The commands must be safe. They must also fit the time and power the rover has. Soon after, the Sun rises on Mars and Curiosity listens for its instructions.
Why nobody has a joystick
All that structure exists for one reason. You cannot steer a rover on Mars live. Data comes in batches, whenever the orbiting spacecraft passes by. The finished list of commands goes back out through NASA’s Deep Space Network, a group of big radio antennas on Earth. So a whole Martian day of work must be written ahead of time. It runs as hundreds of commands. And once it starts, no human can step in. Vasavada notes that on Fridays the team plans three days at once. That is because the results will not come back until Monday. As he puts it, Curiosity works weekends.
The science part of the day is a negotiation. Vasavada describes a screen covered in dots. Each dot marks a possible target for the rover’s cameras, its laser, or the tools on its arm. There are “way too many dots,” he writes. A trained moderator trims the list while teachers, researchers and students from around the world argue for their favorites. Vasavada breaks the tie. He says he rarely has to.
A field of honeycomb cracks
The day he describes begins with a letdown that becomes a discovery. The route planners had aimed Curiosity at ground that looked very smooth in pictures from orbit. They used it to drive 120 feet (37 meters) in one go. That is a long drive for this rover. But the new pictures did not show flat slabs. They showed a surface covered in small shapes with straight edges, “as if someone covered Mars in honeycomb wallpaper.”
NASA put numbers on that ground in its own announcement on July 29, 2026. The cracked shapes sit in a valley nicknamed Valle Grande. Each one measures about 1.5 to 3 inches (4 to 8 centimeters) across. Curiosity shot a 360-degree panorama on June 19 and 20. Those were the 4,930th and 4,931st Martian days of the mission. The picture shows the shapes running off in every direction. They also wrap around a small hill capped with sand, nicknamed Miraflores, roughly 20 feet (6 meters) tall. The mission had spotted small patches of such cracks before. It had never seen them on this scale.
“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” Vasavada said in the NASA release. “We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed.”
Nobody knows yet how they formed. NASA says some shapes found earlier in the mission were clearly dried mud cracks. But other causes can make similar patterns. Repeated swings between warm and cold can do it. So can pressure that squeezes water out of buried sediment. That uncertainty is what the day’s target list was meant to tackle. Which pictures and chemical readings best tell the rival explanations apart?
The engineering half of the day
After the science meeting, Vasavada walks into the room next door. There, a robotics engineer uses a 3D model to check how Curiosity’s arm, which bends at five joints, will reach the chosen rocks. Another engineer runs a test model of the next drive. Their verdict on the ground ahead: no more parking lot, “all curbs.” By noon the science team is done for the day. Then the rover and instrument operators turn the requests into the actual strings of commands.
Here is how long this has been going on. Curiosity landed in Gale Crater on August 5, 2012. Since 2014 it has been climbing a mountain called Mount Sharp, also known as Aeolis Mons. Its layers hold about 3 miles (5 kilometers) of rock built up from old sediment. The rover has climbed through roughly a vertical half-mile (1 kilometer) of it. Along the way it moved from clay-rich mudstones into younger, salty sandstones. Vasavada writes that the team has run this planning routine more than a thousand times.
The limits are just as clear. Curiosity has drilled samples that hold small molecules built on carbon, plus signs of lakes that lasted a long time. That was enough for the team to conclude that Gale Crater could once have supported life. But NASA says plainly that the rover’s data cannot show where those carbon molecules came from. They could be from living things, or from ordinary rock chemistry. Settling that, Vasavada writes, means bringing Martian rock back to labs on Earth. Such a return mission has no confirmed plan or timetable yet.
