At NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, the teams operating the Curiosity rover work each morning on data sent from Mars. Ashwin R. Vasavada, Curiosity project scientist, describes a typical day in the control center, where a few dozen engineers and scientists have a short window to prepare the rover’s activities for the following day.
The rover finishes its exploration day during Earth’s night and transmits its latest images and measurements to a Mars orbiter, which relays them to Earth. The data then waits on servers at JPL and other partner institutions around the world. The operational cycle begins at 8:15 a.m., giving the team three hours to check the rover’s status, analyze new scientific data, and agree on the next activities. An additional four hours are then spent turning these plans into commands, ensuring they are safe and compatible with the rover’s available time and energy.
Reading the rocks
NASA designed Curiosity to search for signs of ancient habitable environments, meaning those with liquid water and the chemicals, nutrients, and energy sources necessary for life. JPL met these requirements with a car-sized vehicle equipped with a drill. The rover was sent to Gale Crater to climb Mount Aeolis, whose layers of sedimentary rock, spanning 3 miles (5 kilometers), preserve a record of environmental conditions dating back about 3.5 billion years.
According to the evidence gathered, a thicker atmosphere once protected streams and lakes. Curiosity has already climbed a vertical half-mile (1 kilometer) of rock layers, where clay-rich strata give way, at higher elevations, to more recent sandstones laden with salty minerals. The team believes lakes persisted for millions of years before the climate became arid and sand dunes covered these bodies of water.
Samples drilled from the lakebed sediments contain small organic molecules, meaning carbon-based ones, which are the building blocks for potential life. For the team, the combination of wet environments, these molecules, and a mix of chemicals similar to what microbes use on Earth to produce energy leads to the conclusion that conditions in Gale Crater were capable of making life possible. Determining with certainty whether life ever actually took hold there, however, will require bringing these rocks back to laboratories on Earth.
Preparing a plan
The day before, the engineers responsible for plotting the rover’s route were instructed to traverse an area that appeared exceptionally smooth and flat in images taken from orbit. After years of difficult off-road driving, they were able to drive the vehicle across 120 feet (37 meters) of this Martian ‘parking lot,’ a significant distance for Curiosity.
The latest images show surfaces covered in small polygons, a few inches wide, resembling a honeycomb. Geologists suspect these polygons outline fractures formed by desiccation, like cracks in drying mud, or by thermal cycles, or by compression. On the screens, each point represents a potential target for the rover’s cameras, laser spectrometer, or arm sensors. The chosen targets will be selected during the debate, with the goal of determining which images and chemical measurements will best distinguish how these polygons formed.
Transmitting the commands
Since it’s a Friday, the activities planned for the next three days will take place over the weekend, and the results will be expected in the next slot on Monday, as Curiosity also works on weekends. Around noon, the science team’s part in the operations is finished. The rover and instrument operators then transform the day’s scientific requests into hundreds of commands, destined for NASA’s Deep Space Network, the antenna network that handles communications with space missions.
