The Sojourner Rover Paved The Way For Perseverance

The Pathfinder lander took this mosaic photo of the Sojourner rover after rolling off the ramp at … [+]

The Perseverance rover’s landing on Mars earlier this month resulted in incredible footage and has already produced some of the sharpest, most detailed photos of Mars ever seen. Last week, sharp-eyed observers noticed the tiny “family portrait” painted on the rover’s hull: outlines of four Mars rovers and the Ingenuity helicopter, a space robot version of the ubiquitous stick figure families we humans like to put on our Earth cars.

Curiosity has been trundling around out there since 2012. In 2018, space fans mourned the loss of the Opportunity rover, whose sibling Spirit lost touch with home back in 2010; the twin rovers reached Mars in 2004. But the very first rover to set wheels on another planet was a tiny space robot called Sojourner.

Spirit towers over a model of Sojourner.


Weighing in at just 23 pounds, the 26-inch-long, 12-inch-high Sojourner rover is dwarfed by its older siblings; Perseverance is about the size of an average car. And back in Sojourner’s day, there were no skycranes like the ones that set Curiosity and Perseverance safely on the Martian surface. Sojourner also didn’t have to bounce to a stop wrapped in inflatable cushions. In Sojourner’s day, rovers arrived on Mars with simple dignity, rolling off the rear ramp of the Pathfinder lander.

Pathfinder’s camera took this photo of Sojourner napping on the lander’s solar panel just before … [+]

The little rover carried an X-ray spectrometer and three cameras, which it used to study the rocks and sediment around the Pathfinder landing site: the northern end of an ancient channel called Ares Vallis, which runs northward out of Argyre Crater and ends in a delta-like fan of sediment called Chryse Planitia. Although Sojourner travelled just over 110 yards, it surprised its human coworkers by lasting 83 Martian days, or sols, when its mission plan only called for 7 sols of roving.

And in that time, Sojourner sent back some amazing images of its home base, dubbed the Sagan Memorial Station. 25 years later, Curiosity and Perseverance have captured more visually impressive and more scientifically interesting photos of Mars, but Sojourner’s photos really made Sagan Memorial Station look and feel like a real, tangible place. The images and mosaics of images from Sojourner’s 484×768 pixel camera feel real in a way that makes a distant robot camp on Mars feel personal, somehow.

The rock just to Sojourner’s left is called Barnacle Bill, and the large rock up ahead is called … [+]

(Take a moment to marvel at the fact that we live in an age where “Who’s your favorite Martian robot photographer?” is a valid question.)

Not only was Sojourner NASA’s first rover, it’s the only rover the agency has named for an actual person: Sojourner Truth, an American abolitionist, suffragist, temperance advocate, and civil rights activist. The formerly enslaved woman fled her enslavers and attained her freedom in 1827. A few years later, she became a travelling revival preacher, and then she began speaking publicly about abolition. As she met other speakers and activists during her career, Truth became an outspoken advocate for suffrage for women and Black people. In fact, she had a public disagreement with Frederick Douglass over the issue of suffrage for Black women; Douglass believed that formerly enslaved men should be the suffrage movement’s priority, but Truth believed firmly in suffrage for all.

The Sojourner rover, like Perseverance, got its name from a contest in which NASA invited students to submit essays proposing a name for the intrepid space robot. The winner, then a Connecticut high school student, chose Sojourner Truth.

“’It’s only logical that the Pathfinder be named Sojourner Truth, because she is on a journey to find truths about Mars,” she wrote. “The Pathfinder should have strong personalities in order to go under harsh conditions like that on Mars.”

I am a freelance science journalist, bringing you interesting science tidbits, tales of discovery and critical looks at everything from deadly diseases to space