The Red Frontier: Mars Rovers' Legacy, Opportunities, and Expert Predictions from the Pioneers of Martian Ventures
48 Mars missions, 6 rovers, 3 still in action, and helicopters soaring the Martian skies. Their objectives? Some data still eludes us. Yet, 2033's delivery of Martian rocks may reveal deeper enigmas.
Issue No 47. Subscribers 7265. Featuring insights from the President of the Mars Society and a Mars planetary scientist.
In our extensive coverage of Mars exploration, we have delved into various aspects, including the obstacles hindering its realization, the design of Martian habitation modules, and even contemplated the significance of Mars exploration in the advancement of mankind as a biological species. By the way, we have a separate article on robots in space.
Presently, practical travel to Mars remains elusive. Consequently, we rely on robotic systems, such as rovers and stations, to gather data from this celestial body. These automated rovers now stand as the vanguard of Mars exploration, paving the way for future missions.
There have been 48 missions to Mars (flyby, orbiters, landing stations, rovers), of which only 13 have been completely successful! Indeed, the technological challenges associated with Martian missions remain significant. There have been 6 rovers in total, of which 3 are currently operating - five of them sent by the USA, and one by China. Rovers have already found evidence of rivers and lakes on Mars in ancient times, found organic molecules, and are also practicing technology for future Martian colonies - examining spacesuit materials and learning how to produce oxygen.
While we may not have physically set foot on Mars yet, our presence is already there through the lens of these rovers, effectively serving as our eyes on the Martian surface.
We talked to Robert Zubrin, the President of Mars Society and the author of “The Case for Mars” and got his thoughts on the role of rovers in future Martian missions:
"Exploration and colonization are key pillars of human progress. Looking ahead, the Mars Rovers are not just pioneering scientific tools, they are the trailblazers, the early settlers of our future. As we envision a Mars colony, these rovers are set to play an integral role. They will assist in laying the foundation, aiding in the construction of habitats, and even supporting resource extraction and agriculture on Martian soil. The Mars Rovers are more than robots; they're our proxies, our eyes and hands in an alien world, ready to build a new home for humanity on the Red Planet."
So, Robots have emerged as the primary explorers in space, far outnumbering human missions beyond LEO, and they have played a crucial role in expanding our knowledge of Mars. Thanks to their tireless efforts, we have garnered a wealth of information about the Red Planet.
Over the years, Mars spacecraft, such as the twin Viking landers in the 1970s, have achieved remarkable scientific feats from stationary positions. These pioneers captured the first up-close photographs of the Martian surface. Additionally, the InSight probe has been diligently listening for Marsquakes, providing insights into the planet's internal dynamics.
However, the true potential for exploration lies in the ability of rovers to traverse the Martian terrain actively. These robotic field geologists can investigate the landscape, piecing together vital clues about its history and evolution.
Despite this, it is still quite difficult to build and operate rovers on Mars due to a number of limitations:
Signal delay of up to 20 minutes due to the huge distance the signal travels. Imagine, you move the mouse on your computer and it moves only after 20 minutes... It's the same with rovers
Electric energy supply is limited, so appliances should operate as efficiently as possible with low power consumption. Therefore, the Mars rovers travel rather slowly (the record of the Opportunity rover is more than 45 km in 14 years)
Harsh climate: on Mars, it is -80 degrees Celsius at night and up to +30 during the day depending on the time of year, there are high radiation conditions, and plenty of rocks on the rover’s way
The rover should be as light as possible to minimize fuel costs at launch.
Mars missions remain complicated, and our success rate for Mars missions (orbiters, stations, rovers) has been around 30%. However, the trend is positive, with more successful missions in recent decades, especially by NASA. Let's take a look at each of the Mars rovers, for each has a unique story to tell.
As of August 2023, there have been six successful robotically operated Mars rovers; the first five, managed by the American NASA Jet Propulsion Laboratory, were (by date of Mars landing): Sojourner (1997), Spirit (2004–2010), Opportunity (2004–2018), Curiosity (2012–present), and Perseverance (2021–present). The sixth, managed by the China National Space Administration, is Zhurong (2021–present).
NASA Mars Rover Family
Undoubtedly, NASA's family of Mars rovers stands out as the most successful mission to explore another planet. What makes them particularly fascinating is that each rover builds upon the knowledge of its predecessors, continuously uncovering fundamental and novel information from various locations on Mars. Indeed, Mars rovers represent substantial investments, with NASA's Curiosity rover costing $2.5 billion and Perseverance around $2.7 billion. Despite their expenses, these missions are significantly more cost-effective compared to manned programs, which would entail even higher costs due to the complexities of supporting human presence on Mars.
Through their missions, these rovers have already provided compelling evidence of Mars' past water-rich environment and favorable conditions for potential life. Currently, the Perseverance rover is meticulously conducting its search for traces of past life on the Red Planet, adding to the remarkable legacy of Mars exploration.
First Mars Rover - Sojourner
The pioneering Mars rover, Sojourner, marked the beginning of our baby steps into planetary exploration when it was launched in 1996. NASA engineers faced uncertainties, as creating such a vehicle was uncharted territory for them, with the USSR's Lunokhods being the only prior experience in this field. Despite the challenges, they embraced the dream, dedicated their efforts, and ultimately succeeded in crafting the rover.
Belief in the vision, coupled with determined endeavors, proved to be the winning formula. The success of Sojourner paved the way for a series of remarkable achievements in Mars exploration, reinforcing the notion that with perseverance and ingenuity, we can overcome any obstacle to unveil the secrets of the cosmos.
Indeed, Sojourner, the first baby explorer on Mars, was relatively small, comparable in size to a microwave. Despite its limited capabilities and the challenges posed by communication delays, it persevered on the Martian surface for three months. Its slow pace was a result of inexperience, and its communication constraints restricted its range to no more than 100 meters from the landing module.
Although primarily a test mission to demonstrate the viability of a rover, Sojourner managed to conduct valuable scientific work with its X-ray spectrometer. This little machine analyzed the chemical composition of 15 Martian rocks and assessed the friction of the Martian soil. Surpassing its initial one-week mission duration, Sojourner impressively survived for 11 weeks before succumbing to the extreme cold of Mars, finally bringing its mission to an end.
The Next Rover - Teenage Twins Spirit and Opportunity
And so, the twins Spirit (landed January 4, 2004) and Opportunity (landed January 25, 2004) came into existence. Two Mars rovers were launched to increase mission reliability. With a size comparable to a golf cart, they represented a significant advancement from the earlier Sojourner. These rovers were equipped with robotic arms, a groundbreaking feature in rover evolution, enabling them to conduct increasingly sophisticated scientific tasks. Their enhanced capabilities included beefed-up cameras, three spectrometers, and a rock-grinding tool to unveil subsurface textures.
Launched a few weeks apart in 2003, both Spirit and Opportunity surpassed expectations by operating for several years, far beyond their initially anticipated three-month lifespan. Throughout their extended missions, these resilient rovers accomplished a remarkable amount of Martian exploration, significantly surpassing their original objectives.
Spirit, during its exploration, made a groundbreaking discovery of rocks that showed clear signs of having been altered by water in the distant past. Meanwhile, Opportunity, right at its landing site, provided the much-anticipated evidence of past liquid water on Mars, a momentous revelation. Subsequently, the rover continued to uncover indications of liquid water at various points in Martian history. Spirit lived for 6 years, he stopped communicating in 2010, presumably due to a power failure.
In an extraordinary feat, Opportunity surpassed all previous records by driving farther than any rover on any celestial body, including that of the Soviet rover's lunar milestone. In 2015, it reached an impressive distance of 26.2 miles (42.2 km), a distance equivalent to a marathon. To celebrate this achievement, mission controllers at JPL commemorated the milestone by awarding the Earth model analog rover a marathon medal and driving it through a symbolic finish line ribbon.
Tragically, Opportunity's incredible journey came to an end in 2019 when an intense dust storm engulfed Mars, obscuring the sun and severing the rover's access to solar power, essential for recharging its batteries. Despite its remarkable resilience, the rover succumbed to the harsh conditions, concluding its mission after a phenomenal tenure of exploration on the Red Planet.
Almost an Adult Rover - Curiosity
NASA's determination to continue advancing Mars exploration led to the creation of the Curiosity rover. Significantly larger than its predecessors, Curiosity boasted the size of a sports car, offering ample space to accommodate an array of scientific instruments. A pivotal addition was the advanced robotic arm, allowing for more complex and diverse investigations.
Due to its substantial mass, engineers devised a completely new landing scheme to safely deliver Curiosity to the Martian surface (landed on August 5, 2012). Moreover, the rover introduced a groundbreaking innovation in its power source: electricity generated through the radioactive decay of plutonium. This provided Curiosity with more energy, enabling faster movement and extended scientific operations.
Curiosity's exploration approach on Mars was indeed revolutionary. It started by surveying the surface with a camera, followed by rock analysis using a special laser. Utilizing its manipulator, the rover then carefully selected suitable rocks for further examination, including drilling into them for in-depth study. This innovative scheme allowed Curiosity to conduct comprehensive and unparalleled research on the Red Planet.
Curiosity has already marked 10 years on Mars and it's still working, in that time it has:
Rounded pebbles shaped by a once-flowing river, the first closeup look at an ancient river on Mars
Discovered evidence of an ancient lake that created life-friendly conditions for potentially many thousands of years
Discovered a range of organic molecules in many different rocks, hinting at environments that had been habitable for millions to tens of millions of years
Measured radiation levels across the surface — helpful for future astronauts
We talked to scientist Alexey Malakhov, who was part of the Curiosity science team and he told us about another important observation:
“Curiosity has sensed methane on Mars, but at the same time methane is not detected at all by the Trace Gas Orbiter (TGO) satellite from orbit (even in the same area as Curiosity). On the one hand this could mean a discrepancy in readings, on the other it may indicate some processes that we do not yet understand. For example, that methane is present on the surface, but it escapes/disperses somewhere already at an altitude of several km, where it is not picked up by the TGO”
All of these rovers became the foundation for the most powerful and maneuverable vehicle that has been to Mars.
A Serious and Mature Scientist - Rover Perseverance
Perseverance (landed February 18, 2021) is essentially a sibling of Curiosity, crafted from spare parts, yet boasting one crucial enhancement: a cutting-edge system for drilling, collecting, and preserving thin rock cores. Its primary mission centers on gathering Martian rock samples for future expeditions and delivering them to Earth, marking a historic milestone as the first robotic return of samples from Mars. This unprecedented achievement will enable scientists to conduct sophisticated analyses of Martian rocks in Earth-based laboratories. For instance, they will be able to accurately determine the age of igneous rocks through the radioactive decay of chemical elements, providing direct evidence of the rocks' age from specific Martian locations.
Perseverance stands out among Mars rovers as a veritable sports car. While Curiosity took two and a half years to cover a mere 10 kilometers, Perseverance accomplished the same distance in just over a year. Impressively, Perseverance set a Martian record by traversing nearly five kilometers in just 30 Martian days (1 Martian day (sol) - 24 hours, 37 minutes, and 22 seconds).
Additionally, Perseverance has a remarkable sidekick, Ingenuity, the first-ever helicopter to grace another world. Despite its diminutive size of only half a meter tall, Ingenuity has far exceeded its designers' expectations. It is important to note that the main difficulty of using such a helicopter is the atmosphere of Mars: the low atmospheric pressure, 1% of that on Earth. Therefore, initially, it was not clear at all whether it would be able to take off. In its first 16 months, the nimble flier completed an astounding 29 flights, far surpassing the initially planned five flights in a month. Ingenuity has played a vital role in scouting paths ahead and identifying scientific targets for the rover. The success of this partnership sets a promising precedent for future rovers, as it is highly likely they will have their own trusty "little buddy" accompanying them on their Martian journeys.
Perseverance carries a couple of experiments that hold crucial implications for future Martian bases.
One of these experiments is MOXIE - the Mars Oxygen In-Situ Resource Utilization Experiment. It serves as a portable generator, extracting oxygen from the Martian carbon dioxide atmosphere. Remarkably, MOXIE has already achieved significant success, producing up to 10 grams of oxygen per hour. This breakthrough has immense potential, as scaling up this technology could be pivotal for sustaining future colonies on Mars.
Another crucial experiment onboard the rover involves the study of materials for future spacesuits. Perseverance carries five samples of spacesuit fabric and helmet material, specially developed by NASA's Johnson Space Center. These samples will be closely monitored by the SHERLOC instrument (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) as they change the Martian environment over time. This study will provide invaluable insights into how these materials degrade on Mars.
The information gathered by SHERLOC will be instrumental for spacesuit designers, enabling them to better understand how the materials perform in challenging Martian conditions. When the first astronauts set foot on Mars, they may have SHERLOC to thank for the development of the advanced suits that will ensure their safety during their historic journey.
New Players on the Mars Arena - Chinese Rover Zhurong’s
While the United States has been a frontrunner in Mars rover exploration, it is not alone in this endeavor. In May 2021, China achieved a significant milestone by successfully landing its rover, Zhurong, on Mars. Zhurong has been actively exploring a portion of Utopia Planitia, a vast basin in the planet's northern hemisphere. The landing site lies near a geologic boundary that might be an ancient Martian shoreline. Interestingly, Zhurong's landing site is billions of years younger compared to other Mars rover locations, making these missions not redundant but complementary.
Zhurong shares similarities with Spirit and Opportunity in terms of size and mobility. Equipped with cameras, a laser spectrometer for studying rocks, and ground-penetrating radar to investigate underground soil structures, the rover mirrors the capabilities of its predecessors.
Among its initial findings, Zhurong has revealed that the Martian soil at Utopia Planitia bears similarities to certain desert sands on Earth. Furthermore, evidence suggests that water may have been present in the area, possibly as recently as 700 million years ago. These discoveries provide valuable insights into the Martian environment and further our understanding of the planet's history and potential for life.
What’s Next?
The global space community continues to push the boundaries of exploration. One major upcoming endeavor is the Mars Sample Return mission, a collaborative effort between NASA and the European Space Agency (ESA). This ambitious project aims to safely bring back samples of Martian material collected by NASA's Mars Perseverance rover to Earth. Once returned, these samples will undergo comprehensive analysis for generations to come, utilizing sophisticated instruments and laboratories only available on our home planet. The mission is expected to arrive on Earth in 2033, although specific details are yet to be revealed.
Another significant mission is ESA's Rosalind Franklin Rover, part of the ExoMars program. Its primary objective is to search for signs of life on Mars. Initially, the rover was intended to be launched alongside a Russian module for landing on Mars. However, due to a breakdown in cooperation on the project, the fate of the rover is currently uncertain. It has a unique drill that allows you to take samples from a depth of up to 2 meters, which has never been done in space, and this is actually the main device of this rover, which will greatly advance us in a number of issues (water, radiation, organics, etc).
However, technology continues to advance, leading to more efficient and powerful Mars rovers. With continued progress, there is a possibility that robots may eventually surpass human capabilities on Mars. But for now, we must work with the limitations of current technology.
Imagine that you have a remote control car and you need to explore a new continent with it. At the same time, this car has a signal delay of 20 minutes and you can travel a maximum of 50 km. Such machines are Mars rovers today. Of course, you will get new knowledge about the continent, but it will not be enough for fundamental research.
Robots have emerged as vital pioneers, laying the foundation for future manned missions in space exploration. Their role in thoroughly exploring fascinating Martian landscapes, selecting materials for spacesuits, and potentially assisting in the construction of Martian bases is undeniable. As technology progresses, robots are poised to become indispensable partners, working side by side with humans in space.
This collaborative approach mirrors the successful utilization of robots on Earth in various industries, from factories to construction sites and emergency situations. Employing these versatile machines on Mars offers numerous advantages, enhancing efficiency, safety, and productivity.
However, while robots excel in numerous tasks, there are certain aspects where human ingenuity, adaptability, and decision-making prowess are unparalleled. In a harmonious blend of human and robotic efforts, the future of space exploration promises to be a dynamic journey, maximizing the strengths of both to unlock the cosmos' secrets.
We would be thrilled to know how you see the development of rovers on Mars. Do you think a robot can fully replace a human? Or are we going to work together side by side?
Reach out to us at hello@spaceambition.org, and share your awe-inspiring insights with us, for together, we can forge a brighter future on Mars and even further.
Great photos in this article. I didn't realize that the Chinese Zhurong rover was so large. These machines are (hopefully) laying the groundwork for human footsteps on Mars sometime in the next decade. It is essential that we make life a multiplanetary species and not give up our spirit of exploration.
This may be possible giving the falling cost-to-orbit due to reusable rocketry: https://www.lianeon.org/p/the-quiet-revolution-in-space-tech