NASA’s recent advancements in shape memory alloy (SMA) technology are creating a better future for more durable and versatile rovers, allowing them to expand space exploration
Although Mars has been studied for centuries, NASA has only explored 1% of Mars’s surface.
While several robotics missions have landed on the fourth planet from the sun, its rugged surface makes it hard to traverse.
Exploring planetary surfaces
To overcome these challenges and explore more of Mars, NASA has recently completed testing a rover on simulated Martian terrain. This testing utilised innovative shape memory alloy spring tire technology developed in collaboration with Goodyear Tire & Rubber at NASA’s Glenn Research Center in Cleveland.
Mobile robots, such as rovers, are designed to explore lunar and planetary surfaces, but they require appropriate tyres suited for the environments they traverse.
Shape Memory Alloys (SMAs) are metals that can revert to their original shape after deformation. Although SMAs have been used in past aerospace applications, their use in constructing high-performance tyres for extraterrestrial rovers is a newer development.
By using SMA’s for extraterrestrial rovers, NASA hopes to address the limitations of conventional materials in extreme environments, allowing for better mobility and durability of space exploration vehicles.
SMA-based tyres
Using SMAs as researchers at NASA Glenn Research Center originally did rover tyres. The researchers have identified that the steel-based spring tyres traditionally used in planetary rovers are vulnerable to plasticising, or permanent deformation when subjected to extreme stress.
This caused a significant issue with the functionality and longevity of rover tyres.
Nickel-titanium SMAs appeared as a game-changing solution due to their ability to endure significant strain and return to their original shape. Unlike usual materials, SMAs accommodate deformation without sustaining damage, making them ideal for the rugged conditions of planetary surfaces.
Testing and validation
In 2024, NASA Glenn engineers worked with Airbus Defence and Space to test SMA spring tyres in a Mars-like environment.
The testing took place in the Airbus Mars Yard, a facility designed to simulate the challenging terrain of the Red Planet. Engineers assessed the tyres’ performance on various surfaces, including rocky inclines and sandy slopes, focusing on stability, manoeuvrability, and resistance to damage.
Observations showed minimal sliding and deformation, with the tyres maintaining stability and effectively traversing obstacles. These findings validated the performance of SMA-based tyres over their traditional counterparts, showing their potential to enhance rovers’ mobility on extraterrestrial terrain significantly.
Expanding applications for SMAs
Building on the success of SMA-based tires, NASA is exploring additional applications for these materials in extreme environments. Research is underway to extend the operating temperature range of SMAs, making them suitable for diverse conditions such as the Moon’s extreme temperature fluctuations.
SMAs could play a key role in habitat construction for lunar and Martian missions. Their energy-absorbing properties make them ideal for shielding structures against micrometeorite impacts, a critical consideration for long-term human presence on other celestial bodies.
Implications for space exploration
By improving the resilience and functionality of key systems, such as rover tyres and habitat structures, SMAs enable NASA to tackle the unique challenges of extraterrestrial environments.
These advancements support the exploration of the Moon and Mars and lay the groundwork for sustainable human habitation on these planets.
Shape Memory Alloys are driving a new era of innovation in space exploration. Through collaborative research and testing, NASA has demonstrated their potential to revolutionise rover mobility and habitat construction.
As the efforts continue to refine SMA technologies, their applications are expected to grow, creating an essential solution for deep space exploration and setting the way to explore more of Mars and other planets.
