Opportunity Rover: Robots on Mars

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It was perhaps the most dramatic birth this channel will ever cover. In January 2004, a bright spot of light streaked across the skies of Arabia Terra. The burning ball of fire sliced through the atmosphere at over 16,000 kilometers per hour, far above the empty desert wastes. But this was no ordinary shooting star, and this was no ordinary desert. Inside the fireball was one of the most advanced pieces of technology ever created: a rover designed to shatter scientific records. Its destination: the frozen, windswept plains of the planet Mars. If the rover survived its traumatic birth, the plan was to have it live in this hostile environment for up to 90 Martian days—90 days in which it would travel perhaps one kilometer from its landing site, conducting science experiments along the way. Instead, Opportunity would remain active on the surface of Mars for a staggering 14 and a half years.

In today’s experimental episode of Biographics, we’re delving into the life of not a man or a woman, but a machine—a robot that traveled to our celestial neighbor and, in doing so, opened humanity’s eyes to the wonders of our solar system.

Normally, when making these biographies, we open unsurprisingly with the subject’s birth, but that’s just not going to work with Opportunity. By NASA’s definition, the rover was born when it emerged from its protective cocoon shortly after impacting the surface of Mars on January 25, 2004. But starting our video there would miss half the story. With this particular subject, we’re going to have to rewrite the rules by opening way back, before Opportunity was even just a twinkle in NASA’s eye.

Back in an era when Mars exploration more often than not meant gigantic, really expensive screw-ups, the path that led to Opportunity, affectionately known as “Oppy,” can be said to have begun on an utterly miserable day back in 1993. That day, everyone at NASA Mission Control was nervously watching as their shiny new craft approached the red planet for an expensive mission costing over $800 million. Mars Observer was an orbital probe that promised to open a whole new era in Martian exploration. Unfortunately, that fatal day, NASA lost contact with Mars Observer just 72 hours before orbital insertion. Despite whispered prayers, clever seeming solutions, and a whole lot of stress, the probe was never heard from again. Just like that, $800 million of taxpayer money had been flushed down a cosmic toilet, and that meant there was going to be hell to pay.

The aftermath of the Mars Observer debacle saw NASA’s biggest institutional shake-up since the Challenger disaster. Faced with an angry Congress in budget-cutting mode, the space agency hastily implemented a new policy with the motto “faster, better, cheaper.” That meant no more hyper-expensive orbiters; instead, cheaper landing craft would spearhead the new phase of exploration, and none would be twice as celebrated as Pathfinder, the first soft landing on Mars since the 1976 Viking missions. Pathfinder was designed to do groundbreaking science while also costing a quarter of the lost Mars Observer.

For our story, though, the key is that the lander came with a bold little experiment attached to it—one that would pave the way for not just Opportunity, but scores of other missions to come. The name of that experiment was Sojourner. Weighing just 11.5 kilograms and a little more than half a meter long, Sojourner was Opportunity’s direct ancestor—a tiny, adorable little robot that ventured away from Pathfinder on a mission of its own.

Being the first Martian rover, Sojourner’s baby steps were tentative at best. Over a lifespan of 83 Martian days, known as “sols,” it covered a mere 100 meters. But in doing so, it changed history in the same way the Wright brothers’ initial flight time of 12 seconds was both unimpressive sounding and an utter game changer. Sojourner’s adventure opened a galaxy of possibilities. Unfortunately, those possibilities were soon put on ice by even more NASA budget cuts, which made a second Mars rover an unaffordable luxury.

Thankfully, though, events would soon conspire to change the agency’s mind. After 1993, 1999 was another year of NASA Martian screw-ups. In the space of three months, two probes—the Mars Climate Orbiter and the Mars Polar Lander—were lost or destroyed, in one case due to a mix-up between metric and imperial units. The death of the two probes put a temporary break on Martian exploration as NASA slammed the 2001 launch window shut to conduct a review. There would be no more Mars missions until 2003.

This pause would turn out to be exactly what scientists needed. Three individuals—Ray Arvidsson and Larry Soderblom—had spent the last decade pitching separate Mars projects to NASA, only to see them lose out to faster and cheaper options. Now, as “faster, cheaper, better” seemed to be dying, the trio began to put their rivalry aside and work on a team pitch. One might not be cheap, but it would certainly be better—a pitch that would ultimately see them take the unofficial role of Opportunity’s “parents.” It was the moment of the rover’s conception, the spark that would soon light up the history of Mars.

NASA Administrator Daniel S. Goldin, although initially hesitant about sending another costly rover to Mars, eventually embraced the idea. He suggested sending two rovers, which would provide built-in redundancy in case one went the way of Mars Observer. It would also mean they could land them on separate parts of the planet and study entirely different kinds of rock. From a mission viewpoint, it was an awesome suggestion.

However, the engineering team faced a daunting challenge. NASA greenlit the project in mid-2000 with an immovable mid-2003 launch date, but the team estimated they would need 48 months to build the rovers. NASA just gave them 34. Thus began the most stressful three years of the engineering team’s lives.

For Opportunity, under sister rover Spirit, this was akin to their period of gestation—the robot equivalent of the nine months humans spend inside the womb. Work on Opportunity’s hardware and software took place 24 hours a day, seven days a week, split between three eight-hour shifts. It was grueling. The twin rovers were giant, golf cart-sized machines weighing 185 kilograms each, equipped with all sorts of cameras and scientific experiments. The software was also a nightmare because of the time lag between sending a signal from Earth and receiving it on Mars. Rovers on the Martian surface can’t be steered in real-time, meaning they need to be capable of operating independently, which makes them far more complex to program.

Even amid the stress, there were precious moments. Perhaps the most significant was the inclusion of a tiny piece of scrap metal within Opportunity’s body, salvaged from the wreck of the Twin Towers. Including parts of it within Opportunity and Spirit was intended as a tribute to the families affected by 9/11, showing that the American spirit had not been crushed.

In 2003, NASA launched a competition to name its new rovers. The winner was a short essay by a young adoptee, Sophie Carlos, who recalled how the distant stars outside her Russian orphanage’s window made her feel less lonely. She wrote, “In America, I can make all my dreams come true. Thank you for the spirit and the opportunity.” The names became official in June that same year, just in time for takeoff on July 7, 2003. A rocket blasted off from Cape Canaveral on a 455 million kilometer journey, with Opportunity traveling nearly a month behind her twin.

But only if they survived the journey. The official birth of these two rovers was not a time of great beauty or joy, but of nail-biting stress.

In early 2004, it looked like NASA might have another Mars Observer on their hands. On January 4, Spirit had landed in the Gusev Crater three weeks ahead of her sister. The first 18 sols crept by without any problems, and then sol 19 began. NASA lost all contact. In the agonizing days that followed, it became clear that a software bug was to blame, and the still unborn Opportunity likely suffered the same problem. Suddenly, it began to seem like 1993 or 1999 all over again—like yet another mission was destined to fail, leaving the combined $820 million spent on the rovers to evaporate into the Martian skies.

But you already know that’s not what happened. With perhaps the loudest exclamation of relief ever uttered by humans, the engineers were able to locate the issue and fix it. A patch was sent to Opportunity while she was still in space, and a scientific miscarriage was averted.

So we get to where our introduction began—with a streak of light shining over the Martian desert. On January 25, 2004, Opportunity landed on Meridiani Planum. It wasn’t exactly a gentle landing, but unlike the controlled descents later rovers like Curiosity would utilize, Opportunity came crashing to Earth inside a giant cocoon of airbags. It smacked into the planet’s surface 26 times before bouncing across the desert wastes, finally coming to rest in Eagle Crater.

Shortly after, a whirring could be heard, and at long last, Opportunity peered out onto the world she had been born into. It was a world unlike anything anyone on Earth expected to see. Opportunity saw a completely different terrain—all sand, craters, and distant cliffs. It was like seeing a brand new planet—a Mars that would be her home for the rest of her life.

While we’ve been using Opportunity as a living creature metaphor to talk about human things like gestation and birth, no one at NASA expected their baby to last as long as any mammal. Instead, Opportunity was designed to be something more like a mayfly—a rover that would hatch out of its cocoon of airbags and then live a mere 90 sols before expiring. The reason for this was all that Martian dust. Unlike today’s nuclear-powered rovers, Opportunity and her sister were solar-powered. The expectation was that this would be fine for around 90 sols, at which point so much dust would collect on the panels that they’d stop working.

That meant Oppy had to start her short life at a sprint and gather as much data as fast as possible. That’s exactly what she did. Barely a newborn, the rover began examining her landing site and almost immediately turned science on its head by analyzing tiny spheres of hematite NASA dubbed “blueberries.” Opportunity discovered they had formed billions of years ago when liquid water flowed across them. It was the first direct evidence of liquid water once flowing across the surface of Mars—a major stepping stone for assessing if the planet was ever habitable.

Sadly, the evidence at this stage was less that Mars had been a nurturing mother and more like a killer queen. The rocks Opportunity examined could have only been formed by extremely acidic water. Still, it was a major achievement for the young rover.

On April 4, 2004, something strange happened: Spirit crossed the 90-sol mark, thereby outliving its expected lifespan. Less than a month later, Opportunity did the same. While NASA intentionally lowballs mission lifespans so everyone is happy when probes exceed them, what was unusual was that Spirit and Opportunity just kept on living and living and living.

It turned out the Martian winds were stronger than anyone had realized—so strong they periodically blasted all the accumulated dust off the rover’s solar panels. In other words, Opportunity might be able to keep going for years. Even so, it would surprise everyone just how long the plucky little rover managed to live.

In many ways, the mid to late 2000s can be thought of as Opportunity’s salad days—a time characterized by being young and carefree. As her controllers on Earth were swept along on the currents of ordinary life through financial meltdowns and elections, Opportunity simply kept trundling along on Mars, following her remarkable mission.

She was just finding out as much about the red planet as possible. In this, she was helped immensely by her sibling. While Opportunity was busy examining Endeavour Crater and identifying the first meteorite ever found on Mars, Spirit was making discoveries of her own.

While Opportunity’s landing site had been a jackpot in terms of science, Spirit had touched down in a place that everyone agreed looked remarkably boring. In fact, it looked so boring that it was only due to a massive fluke that the rover made her greatest discovery. During a drive through some loose dirt, Spirit developed a drag on one of her wheels, which wound up digging a small trench as she moved. This revealed that the soil beneath was brighter—in fact, it was almost pure silica. To be created in such quantities would almost certainly have involved water interacting with rock at a high temperature, such as around springs or hydrothermal vents.

That, in turn, provided yet more evidence of an ancient Mars that once appeared not red and dusty, but blue with seas. It’s easy to forget now, but until Opportunity and Spirit arrived, we had no confirmation if our neighbor ever had liquid surface water. Their joint discoveries transformed our understanding of the early solar system and opened the door for a question that still haunts scientific exploration to this day: Given evidence of ancient water, might Mars have once played host to alien life?

This is serious philosophical stuff. Had the rovers died after these two independent confirmations of liquid water in the distant past, they would have been remembered as major successes. Fortunately, dying is almost what they did. As much as we’ve romanticized Opportunity’s mission, Mars is a hostile and unforgiving environment—even for robots.

In 2007, a massive dust storm enveloped the planet in a howling nightmare of near darkness, reducing the already faint sun to a smudge in an evil sky. Opportunity was barely able to get any juice from her solar panels. From an average of 700 watts, power dropped to only 128 watt-hours—a near terminal decline that threatened to plunge her into eternal night. For six long weeks, Mission Control waited like anxious parents watching over a badly ill child, hoping to see if she would pull back from the brink or simply fade away before their eyes.

Finally, the storm abated, the surface of Mars grew calm once more, and there on the windswept plain, she still stood—Opportunity, her solar panels clean enough to function. A journey far from over. Sadly, though, it would be a journey that she’d mostly make alone. While Spirit had likewise survived the mid-2007 dust storm, the rover’s twin wouldn’t be around much longer.

On May 1, 2009, Spirit’s wheels got stuck in soft soil on the edge of a plateau, leaving her unable to move for nearly a year. NASA tried everything. Eventually, it was decided to use her like one of the agency’s former landers—a mobile platform conducting science in one place. All they could do was tilt her solar panel slightly to get enough sunlight over the Martian winter. But even this would prove to be too much. On March 22, 2010, NASA lost contact with Spirit. Despite over a year of trying, the rover never responded to any of their commands. Finally, on May 25, 2011, they announced the inevitable: Opportunity’s sister was gone, now little more than a lifeless piece of metal turning to dust over half a world away.

Opportunity was now officially alone on Mars. After her twin’s untimely death, Opportunity dealt with the loss in the same way that many humans do—she kept herself busy, setting off on a new mission to explore the 23-kilometer-wide Endeavour Crater and its ancient rocks. Because the journey involved a long detour and a swath of soft sand, it would wind up taking three years—three years in which Opportunity would break the first of many records.

On May 20, 2010, two months after Spirit stopped responding, Opportunity completed the 116th day of her mission’s seventh year. That’s an important number because it’s the length of time the Viking 1 had survived on the Martian surface, which meant that Opportunity was now the longest-running Mars surface mission in history.

From a science standpoint, though, the most impressive moment came after the rover finally reached Endeavour in August 2011. Those ancient rocks the crater held turned out to be perhaps the oldest Mars rocks ever studied, and they told what was by now becoming a familiar story: formed by non-acidic running water some four billion years ago. The rocks confirmed that Mars was once home to rushing rivers, deltas, and churning seas—surface water that lasted perhaps 500 million years.

It was another amazing find—more confirmation that Mars had once been conducive to life. Yet it was also perhaps the last gasp of Opportunity as the cutting-edge scientific tool she had been designed to be. Already, the next generation was on its way. On August 5, 2012, the first of that new generation arrived when Curiosity rover parachuted into Gale Crater, some 8,400 kilometers from Opportunity. Within a decade, it would be joined by even more advanced pieces of technology from NASA’s Perseverance rover and Ingenuity helicopter to China’s Zhurong rover.

With these new arrivals came a subtle shift in the center of gravity. While Opportunity would keep making discoveries, she would no longer be at the forefront. Instead, her fame would come to rest more on her incredible longevity—not to mention all the records broken. In May 2013, that included breaking the NASA record for distance covered on a celestial object, overtaking the 35.744 kilometers clocked in 1972 by the Apollo 17 lunar roving vehicle. A year later, in July 2014, she broke the overall distance record, snatching the crown away from the Soviet Union’s Luna 24, which clocked 39 kilometers on the moon in 1973.

By March 2015, she became the first human-designed machine to finish a marathon on another world, crossing the 42.195-kilometer boundary. Yet even as she pushed the bounds of human engineering to breaking point, there was no getting around one sadly obvious fact: the salad days, such as they were, were now long over, and Opportunity was getting old.

Like in a human, the signs of aging manifested themselves physically—a joint that became stiff and wouldn’t work properly, a wheel that could no longer steer. Eventually, even her memory started to go; commands would be forgotten—the robot equivalent of walking into a room one day and wondering to yourself, “Why am I here?”

At least her longevity was finally bringing Opportunity the recognition she deserved. Back on Earth, the rover had become a celebrity. The cameras that had come equipped with her were easily repurposed for the craze of posting selfies to social media. To be fair, she’d always been famous, but by 2017, some of her operators could remember excitedly following news of her adventures back in 2004 when they were still in