It’s looking more and more like the future of space exploration could involve drones in a big way.
We’ve already seen it here on Earth, where all kinds of flying drones are used by all kinds of people for all kinds of things. Drones are particularly useful in resource development, exploration, imaging, and remote sensing.
Could the future see drones flying around in the thin Martian atmosphere?
NASA has awarded #3.1 million to a group from the Lunar and Planetary Laboratory (LPL) at the University of Arizona to see if they can make that future happen. The group is led by Christopher Hamilton, an associate professor at the LPL. Hamilton specializes in volcanology and lava flows, things that feature prominently on the Martian surface.
On Mars, drones could provide critical support to a rover or lander and enhance the results of the mission for a minimal extra cost, relative to the cost of a rover mission. They could explore areas that are inaccessible to rovers, identify targets of interest, and help find paths through difficult terrain. Drones could potentially even collect samples. Hamilton’s team is calling the idea Rover–Aerial Vehicle Exploration Networks, or RAVEN.
RAVEN represents a change in how NASA has historically approached exploration of other worlds. According to Hamilton, exploration has followed a four-step process until now: flyby, orbiter, lander, and then a rover. That’s more or less how the exploration of Mars has proceeded. First, a series of Mariner probes did flybys to gather information, then the Viking program put a spacecraft into orbit around Mars and a lander on the surface. Then the Pathfinder mission delivered the tiny Soujourner rover to the surface of Mars. Currently, there are several orbiters around Mars, one lander, and one rover on the surface with more on the way.
But with RAVEN, things would look a little different.
“With RAVEN, we’re adding ‘fly’ to that list,” Hamilton said. “And not only that – the whole concept is really geared towards building new technology and procedures for two robots to work together on an extraterrestrial body. We are going to look at how a rover and a drone can work together to maximize the scientific output of such a mission.”
RAVEN will build on the work done with the Perseverance Rover. When Perseverance lands on Mars in about a month, it will be carrying the small Ingenuity helicopter with it. Ingenuity is a technology demonstration mission and will be attached to the Perseverance rover’s belly. NASA expects the tiny helicopter to perform one or more flights during its thirty-day mission.
Hamilton is the principal investigator for the group studying the feasibility of the drone-and-rover concept. They went to Iceland to work on the concept at the Holuhraun lava flow field. Large portions of the Martian surface are covered in lava fields, making the Holuhraun area a desirable analog.
“It’s some of the newest real estate in the world,” Hamilton said about the barren lava fields. “What makes it especially interesting to us is that the lava was emplaced in a sandy area, which is very similar to what some Martian terrains look like.”
Obviously, flying in Earth’s dense atmosphere is a world away from flying in Mars’ thin atmosphere. But testing RAVEN over the lava fields in Iceland will still yield useful insights and information. It’s an excellent opportunity to test out instrumentation for studying lava fields.
Using locations on Earth as analogs for Mars is not new. It’s a standard way of testing technologies and training astronauts. The Icelandic highlands have been used before, and the Apollo astronauts trained there prior to walking on the Moon.
There were eruptions in the Holuhraun area as little as five years ago, making it extremely young terrain. While most volcanic activity on Mars likely ended a long time ago, the lava fields on that planet are some of the youngest terrain features there. Scientists want to study them for a variety of reasons. Some scientists think there may still be some volcanism on Mars. If there is, there may be systems of hydrothermal vents underground.
“Volcanic terrains offer exciting targets for exploration because of their potential to generate habitable hydrothermal systems, which could support or preserve microbial life,” Hamilton said. “RAVEN would make such locations accessible for the first time.”
The lava fields are far too rough and uneven a surface for a wheeled rover to traverse. Not only at Iceland but on Mars, too. So developing a drone is the logical solution to the problem of exploring the fields. In fact, drones may become desirable additions to rovers on all other worlds, simply because flying is better than driving in many cases.
NASA knows this, and they hope to learn more about drone operations during RAVEN’s three-year run. RAVEN is not so much about testing the drone’s flight capabilities since flying on Mars is so different from flying on Earth. Instead, they hope to learn more about sample acquisition possibilities and navigation based on 3D computer terrain models. When combined with the results of the Perseverance Rover’s Ingenuity Helicopter, RAVEN’s results should provide a solid basis for developing future drones that work hand-in-hand with rovers.
“Once Mars Helicopter demonstrates the ability to fly on Mars, we would design the next-generation system capabilities,” Hamilton said. “Specifically, we’d be looking at what you would do with the next-generation architecture.”
RAVEN will be testing various payloads, including lidar, hyperspectral imaging and drilling technology. NASA’s OSIRIS-Rex used lidar to navigate down to the surface of asteroid Bennu and collect samples. Improvements in lidar systems will give future drones powerful autonomous navigation capabilities. Hyperspectral imaging allows RAVEN to take images across the electromagnetic spectrum at once, increasing the amount of data gathered during each flight.
RAVEN also features a claw prototype. The claw can be used to collect rock samples and even scoops of sand. Then it can return samples to its rover.
NASA has a long-standing relationship with the University of Arizona and the Lunar and Planetary Laboratory. The LPL managed the design and construction of the HiRISE (High-Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter. That instrument is making an enormous contribution to the study of Mars. The U of A is also highly involved in the OSIRIS-Rex mission, and the principal investigator is from the LPL at the University.
“It is a testament to the University of Arizona’s long-standing track record in planetary exploration that NASA continues to trust our experts with finding solutions to some of our biggest challenges,” said University of Arizona President Robert C. Robbins. “RAVEN is no exception, as this project is part of the bold vision to land humans on Mars in the not-too-distant future. I am excited to see where this project will lead.”