A Jumping Robot Could Leap Over Enceladus' Geysers

By Andy Tomaswick - February 11, 2025

Locomotion is the mechanism by which organisms move, and it's critically important to understand how different forms of locomotion perform in various environments. This concept is particularly relevant in the field of space exploration, as traditional Earth-based locomotion methods—such as wheeled rovers or aerial drones—often face challenges when applied on extraterrestrial surfaces. Among these, jumping as a form of locomotion has garnered attention as a specialized method for navigating challenging terrains, especially when exploring the icy environment of moons like Enceladus.

Among the funded projects by the NASA Institute of Advanced Concepts (NIAC), one of the most innovative is the Legged Exploration Across the Plume (LEAP) program, designed to leverage a newly conceived jumping robot to explore the lower regions of the geysers that erupt from Enceladus. This particular study utilizes the advancements of the Salto jumping robot, which was initially developed by a team at UC Berkeley and refined further by Dr. Justin Yim during his PhD studies.

Dr. Yim, who is now a professor at the University of Illinois and a grantee for the NIAC Phase I program, highlighted the Salto robot's unique capabilities. Measuring only about 50 centimeters and weighing less than 0.5 kilograms, Salto can leap upward to 100 meters horizontally across Enceladus’s surface. This impressive range provides a significant advantage in an environment devoid of a substantial atmosphere where traditional flying mechanisms hinder the potential for exploration due to their reliance on fuel.

The robotic design allows LEAP to utilize its energy efficiently, requiring relatively little power for multiple jumps without exhausting its battery. The ability to soar above the planet's complicated icy terrain opens vast possibilities for research. It allows direct access into Enceladus' plumes—the finest features of this moon—which are of immense scientific interest, providing vital insights into potential astrobiotic conditions and the ingredients for life.

Your typical rover would struggle to navigate the rugged, icy landscape due to its design, which is optimized for traversing solid ground. In contrast, LEAP’s jumping ability permits it to interact with Enceladus's environment without the limitations faced by traditional robotic vehicles.

"The notion of a robot designed to jump over geysers unconventionally extends the capabilities of robotic exploration and reflects our ongoing endeavors to unlock the secrets of celestial bodies." - Dr. Andy Tomaswick

The Mechanisms Behind LEAP's Jumping Ability

LEAP is not only about jumping; it's designed to master complex movements and adapt to various circumstances during its exploratory missions. For effective navigation, the robot is equipped with:

• Advanced Reaction Wheels: Initially, Salto employed a single reaction wheel to maintain its altitude during jumps. However, LEAP intends to include multiple reaction wheels to enhance its control over its movement, allowing for precision maneuvers during traversal.
• Terrain-Agnostic Features: The robot's design takes into account the unique icy surface of Enceladus, allowing it to activate features that facilitate better landing and take-off, thereby collecting essential scientific data.
• Energy Efficiency: The ability to perform multiple jumps consumes less power while enabling exploration across various terrains within the plumes—the very regions containing insights into potential habitability.

Jumping Through the Geysers

One of the most appealing opportunities that LEAP presents is its capacity to leap directly into Enceladus' geysers. These plumes are composed of water vapor and organic molecules, both indicative of the moon's potential to harbor subsurface liquid water and possibly life. Direct access to these geysers is essential for understanding their composition and origins.

In contexts where the Enceladus Orbilander mission is exploring the upper portions of the geysers during its orbital functions, LEAP would provide a crucial ground-based experiment, capable of collecting much-needed data unobtainable from an altitude. This special mission paradigm highlights a collaborative potential between landers and jumping robots, which can share information, thus expanding the scientific findings of extraterrestrial studies.

Challenges and Considerations

While LEAP is promising, the project must address several engineering challenges. One significant issue is the coordination of reaction wheels for diverse maneuvering options. Achieving a balance between size, weight, and functionality is crucial. The following factors are critical:

Trade-offs in Robot Design

• Size vs. Capability: A compact design leads to greater energy efficiency but might limit the payload size and complexity of instruments. Consequently, LEAP will mainly carry basic equipment like a camera and flow meters instead of more intricate sensors.
• Weight Constraints: Lower weight is essential to achieve the necessary jumping capacity; hence the equipment must be lightweight to ensure that LEAP can operate effectively while having limited battery pack parameters.
• Environmental Factors: The icy surface of Enceladus comprises rough, varied terrain that must be considered to ensure that LEAP can adapt and respond dynamically during operations.

As stated by Dr. Yim, these considerations emphasize the necessity for extensive research on robotics moving forward, especially regarding how exciting new jumping methods can be integrated into future missions that will explore other celestial bodies.

Expected Contributions to Future Research

This innovative design strategy represents a paradigm shift in how we perceive extraterrestrial exploration. The outcomes of the LEAP program could influence the development of future robotic missions.

As advancements in our understanding of hopping and jumping robots evolve, their use may become common in investigations beyond Enceladus. NASA's broader research agenda also anticipates integrating such technologies within missions targeting other moons and planets, such as Europa, to determine their potential for life, pointing to a future where adaptive robotic agents could lead the exploration frontier.

For more information on LEAP and future robotic explorations, consider the following resources:

• LEAP – Legged Exploration Across the Plume
• A Hopping Robot Could Explore Europa Using Locally Harvested Water
• A Robot Hopper to Explore the Moon’s Dangerous Terrain
• Miniaturized Jumping Robots Could Study An Asteroid’s Gravity

Lead Image: Artist’s depiction of the LEAP robot jumping over a geyser on Enceladus. Credit – NASA / Justin Yim

Reference: Universe Today