Modularity is an increasingly vital concept in the design of next-generation space exploration hardware, influencing everything from orbital stations to the vehicles that will navigate alien surfaces. The upcoming Lunar Gateway space station, for instance, will be composed of modules from different international organizations. Applying this same philosophy to planetary operations, researchers have developed a new robotic architecture where a single, adaptable rover system could perform both scientific exploration and heavy-duty infrastructure construction on the Moon or Mars.
This innovative approach, developed by engineers at Germany’s space agency (DLR), centers on a versatile ground vehicle that can connect to a variety of specialized attachments. The system is designed to provide a flexible and efficient solution for the complex challenges of building and maintaining off-world outposts. By creating a standardized framework for robotic operations, the project addresses the core needs of future settlements, particularly the ability to locate and utilize local resources, a practice known as in-situ resource utilization (ISRU). This capability is widely seen as essential for establishing a sustainable human presence beyond Earth.
A Standardized System for Versatile Operations
The architecture is built around a powerful rover that serves as a mobile prime mover, capable of pulling and operating a range of specialized units referred to as “payloads.” The key to the system is a standardized mechanical connection that allows the rover to quickly and reliably couple with any of these payloads. This interface is engineered to do more than simply form a physical link; it also facilitates the flow of electricity from the rover to the payload and can even transfer fluids between them. This multi-function connection allows the rover to transport a payload to a specific location and integrate it with other infrastructure already in place.
The adaptability of the system stems from the diversity of these potential payloads. Depending on mission requirements, a rover could attach to a mobile power supply unit to energize equipment at a remote site. For scientific missions, it might carry a sophisticated suite of instruments to analyze geological features. For construction and industrial tasks, the payloads could be attachments like a shovel, backhoe, or drilling rig. This “plug-and-play” approach eliminates the need for multiple specialized vehicles, each designed for a single purpose, thereby reducing mission mass and complexity.
Advanced Locomotion for Alien Worlds
A critical component of this architecture is the rover itself, which is derived from the TransRoPorter (TRP) concept previously developed at DLR. The vehicle employs a “hybrid” locomotion system that combines the advantages of both wheels and legs. Each of the rover’s wheels is mounted at the end of a long, articulated leg, providing exceptional mobility and stability on challenging terrain. This design allows the rover to step over obstacles or adjust its posture to remain level on steep slopes, capabilities that are crucial for navigating the unstructured and often hazardous landscapes of the Moon and Mars.
This configuration offers distinct benefits over other hybrid mobility systems, such as the one used by the Curiosity rover on Mars. One of the most significant advantages of the TRP design is its speed. The legged arrangement allows for a more efficient and rapid traverse across a variety of surfaces compared to more traditional rocker-bogie suspension systems. Standardized communication and control interfaces are also integral to the design, ensuring seamless interaction between the rover and its various payloads.
Rigorous Simulation and Performance Trade-offs
To determine the optimal design for the rover, the research team conducted more than 1,500 detailed simulations. These virtual tests allowed them to analyze how different configurations would perform under a wide range of conditions without the expense of building numerous physical prototypes. The simulations explored several key variables, including the method of wheel control. One setup was “serial” control, where wheels on an entire side of the rover moved in unison, while another was “parallel” control, where a wheel on each side was paired with another.
Other tested variables included the specific geometry of the legs, the presence or absence of a payload, and the type of terrain the rover was required to cross, including different surfaces and slope angles. The comprehensive results showed that there was no single “best” configuration; instead, the design choices represented a series of trade-offs. Metrics such as the torque required at the hip joints and the rover’s ground clearance were the most heavily influenced by the design, with certain configurations leading to unacceptable outcomes in these areas. In contrast, the overall stability of the system remained remarkably consistent across most designs. The simulations also revealed that power consumption was most significantly affected by whether the rover was carrying a payload, regardless of the specific leg and wheel configuration.
Enabling In-Situ Resource Utilization
A primary application for this modular robotic system is the extraction of water ice on the Moon, a critical step for producing drinking water, breathable air, and rocket fuel. In a typical mission scenario, a TRP-derived rover would first act as a scout, traversing the lunar surface to identify promising locations where water ice may be present. Once a potential deposit is discovered, the rover could return to a base and attach to the necessary equipment, delivered as a modular payload.
With the mining payload attached, the rover would travel back to the site to begin extraction. After the ice has been excavated, the rover could then be used to transport the raw material from the mining site to a processing plant or astronaut habitat where it can be converted into usable resources. This entire operational chain, from prospecting to transportation, could be managed by the same type of rover, demonstrating the immense efficiency and flexibility of the modular architecture. Such complex, multi-stage tasks are made significantly more manageable through the use of standardized connectors and control interfaces.
Future Outlook and Development Path
This research represents another major step forward in DLR’s long-standing efforts to develop advanced legged rovers for space exploration. As the focus of space agencies shifts from pure exploration toward establishing long-term off-world colonies, the ability to build and maintain infrastructure will become paramount. Understanding the optimal configurations for robotic systems that can perform these construction and logistical tasks is therefore critical.
The true strength of this modular concept is the ability to switch between different configurations depending on the immediate context of a mission. While there are currently no firm plans to launch these specific rovers into space, the successful development and simulation of this architecture means the technology has taken a significant leap in readiness. When the call comes to build the first settlements on the Moon or Mars, these versatile robots will be prepared to do the heavy lifting.
