Watch (and listen) how NASA perceived to take the first epic selfie on Mars

persévérer selfie avec ingéniosité

The historic photo of the rover next to a Martian helicopter turned out to be one of the most complex selfies ever taken. The video, with extra sound, highlights the process.

Have you ever wondered how Martian rovers take a selfie? A color video from NASA's Perseverance shows how the rover took the historic photo of itself on April 6, 2021, next to the Mars Creativity helicopter. As a bonus, the vehicle's input, descent, and landing microphone captured the hum of the boom engines during operation.

Selfies allow engineers to check the wear of the rover. But it also inspires a new generation of space enthusiasts: many members of the rover team can cite a favorite photo that sparked their interest in NASA.

"I got into it because I saw an image of Sojourner, NASA's first spacecraft on Mars," said Vandi Verma, chief engineer of Perseverance for Robotic Operations at NASA's Jet Propulsion Laboratory in Southern California. Verma acted as a driver for the agency's "Opportunity" and "Curiosity" vehicles and helped set up Curiosity's first selfie, taken on October 31, 2012. "When we took our first selfie, we didn't think it was going to get so creative and routine," she said.

The video from one of Perseverance's navigation cameras shows the robotic rover's arm moving and maneuvering to capture the 62 images that make up the image. What it doesn't capture is the amount of work required to make this first selfie. Here's a more in-depth look.

NASA's rover captured a historic group selfie with a Mars Creativity helicopter on April 6, 2021. But how was the selfie taken? Vandi Verma, Perseverance's chief engineer for robotic operations at NASA's Jet Propulsion Laboratory in Southern California, explains the process in this video. Credit: NASA/JPL-Caltech/MSSS

working as a team

The persevering selfie came together with the help of a core group of a dozen people, including rover drivers, engineers who performed tests at the Jet Propulsion Laboratory, and camera process engineers who developed the camera footage and image processing and assembled them. It took about a week to schedule all the required individual orders.

Everyone was working on "Mars time" (the day on the red planet is 37 minutes longer than on Earth), which often means getting up in the middle of the night and enjoying sleep during the day. These team members sometimes give up this sleep just to take the selfie.

NASA's Persistent Mars probe captured a selfie with its Ingenuity helicopter, shown here about 13 feet (3.9 meters) from the rover. This image was taken with the WASTON camera on the robotic arm of the rover on April 6, 2021, the 46th day of Mars, or Day of the Sun, of the mission. Credit: NASA/JPL-Caltech/MSSS

JPL worked with Malin Space Science Systems (MSSS) in San Diego, which built and operated the camera responsible for the selfie. The camera, dubbed WATSON (Topographic Sensor for Wide-Angle Operations and Electronic Engineering), is primarily designed for detailed close-ups of rock formations, not wide-angle images. Since each WATSON image covers only a small part of the scene, the engineers had to order the rover to take dozens of individual photos to produce the self-portrait.

"The thing that got the most attention was putting Ingenuity in the right place in the profile picture," said Mike Raven, director of advanced projects at the MSSS. "Because of its small size, I think we did a good job."

This computer simulation shows NASA's "Persevering Mars" rover taking its first self-portrait, on April 6, 2021. A view of the rover's WATSON camera was included to show how each of the 62 images was taken before being sent back to Earth and linked together in a selfie. Credit: NASA/JPL-Caltech

When the images come down from Mars, the MSSS image processing engineers begin their work. They start by cleaning up the imperfections caused by the dust that has settled on the camera's light detector. Then they group individual photo frames into a mosaic dataset and read their layers using the program. Finally, the engineer twists and cuts out the mosaic so that it looks more like an ordinary camera image that the audience is used to seeing.

computer simulation

Like Rover Curiosity (this black and white video Since March 2020, how a selfie is taken), Perseverance has a rotating tower at the end of its robotic arm. Along with other scientific instruments, the tower includes the WATSON camera, which stays focused on the rover while taking selfies while being tilted to capture part of the scene. The arm acts as a selfie pole, remaining completely out of frame in the final product.

It's harder to persevere to pull a selfie stick in action than Curiosity. Where Curiosity has a width of 22 inches (55 cm), the tower of perseverance is much larger, with a width of 30 inches (75 cm). It's like waving something whose diameter of a road bike wheel is a few centimeters in front of the perseverance mast, the "head" of the rover.

The JPL has a program in place to ensure that the pole does not hit the rover. Each time a collision is detected in the ground simulations, the engineering team adjusts the trajectory of the arm; The process is repeated dozens of times to ensure that the movement of the arm is safe. The final control sequence brings the robotic arm "as close as possible to the rover's body without touching it," Verma said.

They run other simulations to ensure, for example, that the Ingenuity helicopter is correctly positioned in the final portrait or that the microphone can pick up the sound of the robotic arm motors.

selfie voice

In addition to the input, descent, and landing microphone, the Perseverance embeds a microphone in its SuperCam instrument. The microphones are a first for NASA's Mars spacecraft, and the sound promises to be an important new tool for rover engineers in the years to come. Among other uses, it can provide important details about the proper functioning of something. In the past, engineers had to content themselves with listening to an experimental vehicle on the ground.

"It's like your car: even if you're not a mechanic, you sometimes hear a problem before you realize something is wrong," Verma said. "

Although they haven't heard anything yet, the hum of the engines seems surprisingly musical as it reverberates into the rover's body.

Learn more about the mission

Astrobiology is one of the main objectives of the persistence mission to Mars, including the search for signs of ancient microbial life. It will characterize the planet's geological rover and past climate, paving the way for human exploration of the Red Planet, and will be the first mission to collect and store Martian rocks and regolith (fractured rocks and dust).

Subsequent NASA missions, in cooperation with the European Space Agency (ESA), will send spacecraft to Mars to collect these surface-sealed samples and send them back to Earth for further analysis.

The Mars 2020 Perseverance mission is part of NASA's lunar exploration approach to Mars, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

The Jet Propulsion Laboratory, operated by the NASA-administered California Institute of Technology in Pasadena, California, built and operated the rover's operations.

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