NASA’s Perseverance Rover Took Its First Historic 62-Image Selfie With Ingenuity Helicopter

Just a few days after National Selfie Day, NASA showed an interesting piece from its Perseverance Rover, who took its first selfie from Mars with the Ingenuity Mars helicopter.

In addition, the Rover's microphone took the sound of the arm's motors operating, NASA said in its Mars Exploration Program website. These selfies would help engineers in checking the wear and tear of the Rover.

On April 6, NASA's Perseverance rover took a historic selfie beside the Ingenuity copter on the Martian surface. It used a camera, called WATSON, at the end of its robotic arm to snap the shot. Surprisingly, when the final image was released by the US space agency, the robotic arm was not visible and it made viewers wonder how the “selfie” was taken. Now, NASA has explained how the complex feat was achieved. It said the rover took 62 individual images that were then stitched together into a single selfie.

“I got into this because I saw a picture from Sojourner, NASA’s first Mars rover,” said Vandi Verma, Perseverance’s chief engineer for robotic operations at NASA’s Jet Propulsion Laboratory in Southern California. Verma worked as a driver for the agency’s Opportunity and Curiosity rovers, and she helped to create Curiosity’s first selfie, snapped on Oct. 31, 2012. “When we took that first selfie, we didn’t realize these would become so iconic and routine,” she said

Video from one of Perseverance’s navigation cameras shows the rover’s robotic arm twisting and maneuvering to take the 62 images that compose the image. What it doesn’t capture is how much work went into making this first selfie happen. Here’s a closer look.

Perseverance’s selfie came together with the help of a core group of about a dozen people, including rover drivers, engineers who ran tests at JPL, and camera operations engineers who developed the camera sequence, processed the images, and stitched them together. It took about a week to plot out all the individual commands required.

Everyone was working on “Mars time” (a day on the Red Planet is 37 minutes longer than on Earth), which often means being awake in the middle of the night and catching up on sleep during the day. These team members sometimes passed up that sleep just to get the selfie done.

JPL worked with Malin Space Science Systems (MSSS) in San Diego, which built and operates the camera responsible for the selfie. Called WATSON (Wide Angle Topographic Sensor for Operations and eNgineering), the camera is designed primarily for getting close-up detail shots of rock textures, not wide-angle images. Because each WATSON image covers only a small portion of a scene, engineers had to command the rover to take dozens of individual images to produce the selfie.

“The thing that took the most attention was getting Ingenuity into the right place in the selfie,” said Mike Ravine, Advanced Projects Manager at MSSS. “Given how small it is, I thought we did a pretty good job.”

When images come down from Mars, the MSSS image processing engineers began their work. They start by cleaning up any blemishes caused by dust that settled on the camera’s light detector. Then, they assemble the individual image frames into a mosaic and smooth out their seams using software. Finally, an engineer warps and crops the mosaic so that it looks more like a normal camera photo that the public is used to seeing. 

The video shared with the blog had the sound of the robotic arm twisting and maneuvering to take the images. Vandi Verma, Perseverance's Chief Engineer for Robotic Operations, explained the difference between a selfie taken by a human and the one taken by the rover. She said that even with the robotic arm fully extended the camera cannot cover the entire rover in a single image as the WATSON camera is designed to capture close-up detail shots for scientific research. So scientists took multiple images and then stitched them together for the selfie.

Verma worked as a driver for NASA's Opportunity and Curiosity rovers. She also helped create Curiosity's first selfie snapped on October 31, 2012. This image was composed of 55 high-resolution images.

“When we took that first selfie, we didn't realize these would become so iconic and routine,” said Verma.

A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

June 26, 2021