“Still operating on an $85 million budget,” the notion of Mars chopper Ingenuity falling prey to something like “too much sand” might seem ridiculous. Yet this exact thing brought the little chopper’s flight career to an abrupt close. Ingenuity’s final flights over the Jezero Crater have laid bare the critical weakness of the chopper’s navigation design: the inability to navigate an area without marked topographical points to follow. This very issue has been the engine behind the current crop of Earth-based testing to confirm the next crop of aerial expeditions to the Red Planet have the capability to navigate the most barren regions of the planet.
1. Ingenuity’s Navigation Weak
Ingenuity was intended to make estimates of motion based on tracking the visual features on the surfaces. “Ingenuity was intended to fly over very textured terrain, making estimates of motion based on tracking visual features on terrain. However, Ingenuity had to fly over regions with less interesting terrain sooner or later,” stated JPL researcher and drone pilot Roland Brockers. Ingenuity made its 72nd and final flight on steep, featureless sand dunes. Because these surfaces did not provide enough texture, its navigation system began making estimates of velocity inaccurately, causing Ingenuity’s hard landing and destroying its rotor blades. According to Ingenuity’s first pilot Håvard Grip, “The lack of surface texture provided insufficient information to its navigation system.”
2. Extended Robust Aerial Autonomy
In an effort to resolve these shortcomings, NASA’s Jet Propulsion Laboratory is working on what is known as Extended Robust Aerial Autonomy, which is essentially software aimed at maintaining reliable operations when it comes to landing and movement in regions of low texture, including sand dunes, smooth rock patches, and other areas rich in scientific knowledge but lacking texture.
3. Death Valley: A Mars Analogue Since the 1970s
Death Valley National Park has long served as a technological proving ground for Mars development, dating back to the Viking missions. Mars-like volcanic rocks and barren slopes line Mars Hill, making Death Valley an ideal location for the operation of systems as diverse as rover landing control, flying reconnaissance, or, as it is doing now, flying scientific reconnaissance. The JPL team was granted only the third-ever scientific drone license for Death Valley.
4. Field Testing in Extreme Heat
Towards the end of April and early September, the teams used three research drones to explore Mars Hill and Mesquite Flat Sand Dunes. The tests took place under conditions of more than 113 °F (45 °C), with the team operating from under the canopies to analyze the data from the flight of the drones using laptops. The tests examined the effect of filters on ground tracking while also showing the software capability to identify safe zones around rocks.
5. Dumont Dunes: The Ultimate Low-Tech Challenge
When it came to testing regions with very few visual features, the team focused on Dumont Dunes in the Mojave Desert. This location was previously employed for testing the mobility of the Curiosity rover back in 2012. The rippled sand dunes offered a perfect analogue for regions with few features that puzzled the Ingenuity drone.
6. LASSIE-M: Legged Mobility for Hazardous Terrain
NASA’s mobility initiative is not limited to rotorcraft. At White Sands National Park, the team tested the quadruped robotic prototype “LASSIE-M,” developed to change its gait in response to surface feedback. Motors in its legs determine texture: hardness, softness, or crust formation, allowing it to move effectively in rocky slopes and sandy dunes where four-wheel vehicles might sink or become stuck. Geologist Nathan Williams said, “Scientifically interesting areas aren’t always found in benign terrain, so we seek to be ready to explore even more difficult terrains than Ingenuity.”
7. MERF: Winged Flight for Long-Range Mapping
NASA’s Langley Research Center is working on a project for a Mars Electric Reusable Flyer (MERF) aerial vehicle sporting one wing and two propellers for vertical takeoff and hovering capability. The aircraft is designed to be light enough to lack a fuselage and a tail section. Thus, it has a high speed for efficient flight and a capability to map out its surroundings using sensors embedded on its underside when exploring Mars, where it will encounter a thin atmosphere. A scaled-down model of the MERF has been used to test aerodynamics and the effectiveness of light materials prior to its deployment on Mars.
8. A Coordinated Mobility Strategy
Extended Robust Aerial Autonomy, along with LASSIE-M and MERF, is one of the group of technology projects that has been selected under the Mars Exploration Program and involves a total of 25 projects that have been funded this year. Combined, these projects work towards developing an adaptable technological tool that can access areas that were deemed unapproachable in the past, using air, ground, and combined approaches that are being improved in the most Earth-like Martian conditions. In working to overcome Ingenuity’s challenges in navigating and by testing new technology in analog sites like Death Valley and Dumont Dunes, NASA is paving the way for scout craft that are capable of exploring the Martian environment’s most hostile regions without getting lost.