After nearly 20 years circling the Red Planet, NASA’s Mars Reconnaissance Orbiter (MRO) is pulling off a surprising new stunt—flipping almost completely upside down to get a better look underground. This bold maneuver, known as a “very large roll” or VLR, is helping scientists uncover hidden water ice beneath the Martian surface in places previously impossible to probe. It’s a thrilling new chapter for a seasoned spacecraft—and it could have huge implications for future human missions.
What Exactly Are These “Very Large Rolls”?
NASA has taught MRO to perform 120-degree backward rolls—far beyond its original 30-degree tilt capacity—to give its radar, SHARAD (Shallow Radar), a clear, interference-free view of Mars’ surface. In its default position, SHARAD sits at the rear of the spacecraft and often gets blocked by the spacecraft’s structure, which weakens its radar signal.
But now, when Mars Reconnaissance Orbiter performs a full backward roll, SHARAD’s antenna has an unobstructed path to fire radar pulses deep into the Martian subsurface. These radar returns have seen a dramatic increase in clarity—nearly 10 times stronger—enabling scientists to detect buried features that were once out of reach. According to NASA’s Jet Propulsion Laboratory, the upgraded radar signal has already opened up previously inaccessible regions on Mars for exploration.
This technique marks a significant leap in the mission’s capabilities and gives scientists powerful new tools to uncover the Red Planet’s secrets.
Why These Rolls Are a Scientific Breakthrough
The clearer radar signals achieved through these VLRs have already enabled MRO to probe 800 meters below the surface in the Medusae Fossae Formation and up to 1.5 kilometers in Ultimi Scopuli, near Mars’ south pole. These are depths that SHARAD wasn’t reaching effectively before.
That’s a big deal. Being able to explore these layers of Martian ground allows scientists to distinguish between rock, sediment, and, most importantly, subsurface water-ice. Previously, interference and signal loss blocked much of this data. Now, with a stronger signal and improved clarity, scientists can create more accurate maps of Mars’ underground structures.
What makes this even more exciting is that these regions might contain large stores of water-ice. Finding these resources is crucial for future crewed missions. Water isn’t just for drinking—it can be turned into breathable oxygen and rocket fuel, which means human explorers could live and launch from Mars without having to haul every resource from Earth.
How These Complex Rolls Are Made Possible
These dramatic flips aren’t something MRO was originally built to do. Rolling 120 degrees disables its solar arrays from tracking the sun and disconnects its high-gain antenna from Earth. That means, for a short period during each roll, MRO runs solely on battery power—and is completely out of contact with NASA.
Before every roll, mission engineers perform careful simulations to ensure the orbiter can maintain power, keep instruments thermally stable, and recover communications once the roll ends. Solar energy must be stored up beforehand, and all other operations must be precisely choreographed to avoid disruption.
This complexity is the reason MRO currently performs only one or two of these extreme maneuvers per year. However, the team is working on refining the process to eventually allow more frequent rolls. If successful, it could significantly accelerate our understanding of Mars’ underground resources.
Giving New Life to Aging Instruments
What makes this innovation even more impressive is how it’s helping not just SHARAD, but other aging instruments onboard MRO as well—especially the Mars Climate Sounder (MCS).
By 2024, MCS’s motorized gimbal, which allows it to tilt and scan atmospheric layers and the surface, became unreliable due to wear and tear. Rather than give up on its data-collecting abilities, the team repurposed the VLR maneuver to serve MCS’s needs. The rolls now allow the spacecraft itself to orient the instrument for accurate readings—no gimbal required.
This clever workaround is extending the life and usefulness of multiple systems aboard MRO. It’s a perfect example of NASA’s knack for doing more with less and showcases how creative thinking can overcome aging hardware challenges.
Why This Matters for the Future of Mars Reconnaissance Orbiter Exploration
The ability to detect water-ice beneath the Martian surface isn’t just a scientific curiosity—it’s a crucial stepping stone toward putting humans on Mars. Water is one of the heaviest resources to carry from Earth, so finding it on Mars can dramatically reduce mission costs and risks.
Moreover, the location and depth of ice deposits reveal important clues about Mars’ climate history. Layers of sediment and ice form over thousands—or millions—of years, preserving a frozen timeline of Martian environmental conditions. Understanding this helps scientists learn whether Mars was once habitable, and how its climate evolved to what we see today.
These insights feed into broader efforts to prepare for human exploration, study Mars’ potential to support life, and even learn more about Earth’s climate by comparison.
Old Spacecraft, New Tricks (Mars Reconnaissance Orbiter)
It’s remarkable that MRO, launched in 2005 and operating since 2006, is still pushing scientific boundaries nearly two decades later. The fact that such a sophisticated maneuver was made possible without new hardware—only software upgrades and planning—is a testament to the engineering foresight behind the mission.
Rather than seeing the spacecraft’s age as a limitation, NASA scientists saw an opportunity. By rethinking how they use existing technology, they’ve given MRO a second wind. Its instruments, once limited by orientation and interference, are now delivering higher-quality data than ever.
This shift in thinking is already influencing how future missions are planned. Engineers and scientists are realizing that flexibility in design—both hardware and software—can extend the scientific lifetime and value of space missions for many years beyond their original scope.
What’s Coming Next
Encouraged by early results, NASA scientists are now planning more of these large roles to target key zones across the Martian mid-latitudes and poles. These areas are believed to contain vast underground reservoirs of frozen water, just beneath the surface. Each new roll adds to the growing map of Mars’ hidden resources.
If the team can streamline the planning and safely execute more frequent flips, the scientific payoff could be tremendous. With clearer radar data, researchers can zero in on landing sites for future crewed missions, identify ISRU (in-situ resource utilization) opportunities, and build a clearer picture of how water shaped Mars’ evolution.
MRO is also expected to work in tandem with upcoming missions, like the proposed Mars Ice Mapper, which would further refine our ability to scan the Martian subsurface from orbit.
Conclusion
NASA’s decision to teach the Mars Reconnaissance Orbiter a dramatic new maneuver—rolling it nearly upside down—has paid off in a big way. The SHARAD radar is now sending back clearer, deeper, and more revealing data about the Red Planet’s underground structures. This data is not just academically exciting—it has real-world applications for future missions and for humanity’s dream of setting foot on Mars.
More than that, it’s a reminder of how creativity, adaptability, and smart engineering can breathe new life into even the oldest of spacecraft. MRO’s “very large rolls” may look like a simple tilt, but in reality, they represent a giant leap for Mars science—and for the way we explore our solar system.
Source
https://www.space.com/astronomy/mars/nasa-teaches-mars-orbiter-to-roll-over-in-quest-to-find-red-planet-water
https://www.tucsonsentinel.com/local/report/062725_mars_orbiter/mars-orbiter-learns-new-tricks-as-tucson-linked-spacecraft-continues-search-water/
