Perseverance

At 4 pm today, NASA’s Perseverance rover touched down on the surface of Mars. It is the agency’s most ambitious mission yet to the red planet. Launched last July aboard an Atlas V rocket, it is huge—SUV-sized and jam-packed with gadgets and scientific instruments. Onboard are 23 cameras, lasers, X-rays, a spectrometer, a robotic arm with a drill to bore into rocks, and ground-penetrating radar, all powered by plutonium to keep the batteries topped up.

The journey to get to this point has been remarkable. After seven months, the spacecraft hit the thin Martian atmosphere traveling at 12,000 miles per hour, or 3.4 miles per second. Years of planning, research, engineering, testing, troubleshooting, and a 300 million mile journey came down to just a few moments. In what NASA calls “seven minutes of terror” the capsule entered and descended through the thin Martian atmosphere guided entirely by internal systems. Its heat shield protected it from 2,400 degree temperatures, thrusters aimed it toward the designated landing area, a supersonic parachute deployed. Then, in a complex and amazing maneuver called the sky crane, the rover was lowered on cables from the descent stage while rockets fired, hovering a few yards above the ground. The cables detached and the descent stage flew off to crash a safe distance away. There was nothing the flight crew could do should something have gone wrong. In fact, with the 11-minute delay in communications, by the time they received the signal that EDL (entry, descent, and landing) had begun, the rover was already on the surface, one way or the other. They could only cross their fingers, trusting that they’ve done everything they can.

I’ve been fascinated with the Mars missions ever since the (comparatively tiny) rovers Spirit and Opportunity arrived in 2004. They were equipped primarily with the tools of geology, searching rocks and sediments for signs of water. It was the photos they sent back, though, that were so mesmerizing. National Geographic published 3D panoramas taken from the rovers (even included the glasses!), and I pored over those boulder-strewn desert landscapes. How lucky was I to live in a time to see this! A truly alien world—eerily familiar, but different. There were rolling hills, mountains, cliffs, and desolate plains under a hazy orange sky, all so so unfathomably far away.

Spirit and Opportunity had a planned lifespan of a few months, but they ended up lasting far beyond that. Opportunity in particular lasted an incredible 15 years and traversed some 28 miles of the Martian surface. Since then, there have been also been the Curiosity rover and Insight lander.

Perseverance will spend its time exploring Jezero Crater, which is believed to be an ancient lakebed. Aerial images show inlet and outlet channels and a delta, obvious signs of flowing water. Thanks to Spirit and Opportunity, we already know that liquid water existed at one time on Mars (perhaps still does somewhere), so this mission will go one step further, searching for organic molecules, the chemical signatures left by potential former life. It’s also possible that microbial life could have left physical traces in the form of fossilized structures called stromatolites, as they do on Earth, or in microscopic etchings on rock. The rover will investigate.

An ancient river delta in Jezero Crater. [ESA/DLR/FU-Berlin]

Its instruments are a mouthful of acronyms: PIXL (Planetary Instrument for X-Ray Lithochemistry), SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals), MEDA (Mars Environmental Dynamics Analyzer), and RIMFAX (Radar Imager for Mars’ Subsurface Experiment). In short, it will select and vaporize rock and dust with laser or use a drill to bore and collect rock samples. It will use ultraviolet light and spectrometers to analyze their chemical composition and x-rays to scan for physical traces of life. It will take measurements of temperature, wind speed and direction, pressure, relative humidity, and dust size and shape, and ground-penetrating radar will provide centimeter-scale resolution of the geologic structure of the subsurface. The samples it collects will be stored in super-sterile cylinders that will be dropped in strategic locations, in anticipation of collection by a subsequent mission that will return them to Earth. Such a mission is possible to launch in the late 2020s.

Perseverance also has a few fun additions. It will deploy a small helicopter (nicknamed Ingenuity) for a series of 3-minute test flights. Drones are faster and more mobile than rovers for exploration, so engineers are hoping that the technology’s role can be expanded in future mission. It will test MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment), a system for creating oxygen from atmospheric carbon dioxide. If successful, it could prove useful to manned missions, either for breathing or burning of fuel for return trips. Finally, Perseverance has microphones to record the first audio from the red planet. I’m counting on that first clip of the Martian wind to be just as captivating as those 3D images all those years ago.

I’ve always admired NASA’s ability to balance the needs of scientists and researchers with current engineering capabilities and long-term planning for future missions. They have managed to stay (mostly) above the political fray. It is among the most well-respected government agencies, with an overwhelming majority of Americans agreeing that its work is a good investment. Its achievements are applauded around the world. NASA represents the best of us.

In the coming days, weeks, and months, we can expect to get high resolution images, reports of instrument testing and diagnostics, and maybe a flight of the copter. I’ll be watching closely for updates. But for now, its good just to know that it made it. Watching the cheers and fist bumps of the fully-masked, half-capacity NASA control crew once safe touchdown was confirmed brought back a wave of pride and awe for these missions. After such a difficult year, the name of the new rover is appropriate. We can do big things. We can keep going. It’s good to be reminded of that.