Thursday afternoon, Perseverance, NASA’s most ambitious autonomous rover, will attempt the agency’s toughest landing on Mars. Perseverance involves a series of science experiments that will search for signs of life, launch a drone helicopter, and record the audio of the planet for the first time. But the conduct of these experiments depends solely on “Percy’s” ability to hold the landing.
“I just want to say that landing on Mars is difficult,” said Gregorio Villar, systems engineer on the entry, descent and landing team at NASA’s Jet Propulsion Laboratory. Historically, about half of all attempted Mars landings by the United States have failed, and Perseverance will be the largest rover attempting to do so. The location also complicates matters: the rover is targeting Jezero Crater, a dry remnant of what scientists believe to be a river delta 3.5 billion years ago. “Usually we try to go to safe places, like very flat areas that are not too scary,” says Villar. “But it’s kinda boring for scientists, isn’t it?”
Perseverance launched from Cape Canaveral Air Force Base in Florida on July 30, but its journey really started about ten years ago. “There are literally thousands of people over 10 years who have worked on this,” says Villar. New technology on board the craft was designed to make difficult landings more realistic and Mars missions more intriguing possible.
This mission is mainly centered on the search for ancient traces of life. Once in the crater, Perseverance will use tools like the Planetary Instrument for X-ray Lithochemistry to examine soil textures for patterns indicating past microbial activity. The autonomous driving the rover is equipped with a very first microphone, plus 23 cameras, including the SuperCam, a laser and camera setup that will analyze the chemical makeup of Martian dust and minerals, potentially revealing traces of life from a long time ago.
The rover also carries technology unrelated to the search for extraterrestrials. Ingenuity, a small helicopter aboard Perseverance, will perform the first controlled flight to another planet. Wright Brothers moment for JPL. And the experiments are powered by a battery that recharges continuously with Plutonium fuel made in the USA.
Since July, as Perseverance heads to Mars, the many antennas on board have been sending high-frequency signals to engineers on Earth. An X-band signal relayed a sort of “heartbeat” throughout the rover’s journey. “Every certain number of seconds it’s going to be like, ‘OK, I’m still good, I’m still good,’” says Villar.
Separate ultra-high frequency signals in the megahertz range can also transmit heavier files, such as images from Perseverance’s on-board cameras. The rover will communicate with the satellites orbiting the red planet, and these will transmit its signals to Earth. (From NASA Mars Reconnaissance Orbiter, the Maven satellite, and their cousins at NASA have a new company: United Arab Emirates Mission Hope recently placed a probe into orbit, which returned its first images.) These communication channels will continue to ping NASA on the day of landing.
But even with all the cameras and microphone, don’t expect instant video feed. The transmission of these large files will take some time. Even rudimentary communications like the “heartbeat tone” take 11 minutes and 22 seconds to reach Earth at this time of year. This delay means that NASA engineers will not have real-time communication with the craft during the famous “seven minutes of terror”, when it will have to survive its descent into the Martian atmosphere and land autonomously.