When NASA’s Perseverance rover lands next week, it will transport one of the strangest devices ever seen on Mars: a drone destined to make the first controlled flights on an alien planet.
Dubbed “Ingenuity”, the drone weighs just 4 pounds and stays stowed under the rover’s belly while Persistence goes through its first surface checks and experiments.
But by mid-April, the rover will explore a flat area with no large rocks to deploy the drone, and soon after, Perseverance will release Ingenuity to make its first flights on Mars.
“It’s quite unique in that it’s a helicopter that can fly around,” said Tim Canham, the operations leader of the Ingenuity project at NASA’s Jet Propulsion Laboratory in California.
“There was a balloon mission on Venus years ago, so we cannot claim to be the first plane,” he said, referring to the two Soviet Vega space probes that used balloons attached to scientific instruments in the clouds on Venus in 1985. “But we can claim to be the first powered aircraft outside of Earth.”
Canham will coordinate the five test flights scheduled for the Ingenuity drone over 30 days, each with an interval of at least three days.
“The first flight will be really easy – it just goes straight up, floats and goes straight down,” he said. “Then we do a number of flights where we go horizontal to test how it works.”
The car-sized Perseverance rover has seven complex scientific instruments, so it can take panoramic video, track the weather, perform ultraviolet and X-ray spectroscopy on anything it finds, and look for signs of ancient microbial life.
But Ingenuity won’t conduct science on its test flights. It only takes pictures of the Mars terrain with its two cameras, one facing forward and one facing down.
Instead, the Ingenuity project is designed to show that drones can be an important addition to the ongoing explorations of distant planets, Canham said.
“Our job is really to prove that the aerodynamics, as we tested them here, also work on Mars,” he said.
Mars is difficult to fly, which is why Ingenuity is so light and requires two counter-rotating four-foot helicopter rotors to stay in the air.
Although Mars’ gravity is only one-third that of Earth, the red planet has a very thin atmosphere with only 1 percent the pressure of Earth, making flying difficult.
Mars is also freezing – it drops to minus 100 Fahrenheit at night in the giant Jezero crater where the rover will land, perhaps as much as 40 degrees during the day. The extreme conditions will test the design of the drone.
Canham explained that Ingenuity only has enough battery power that each of its test flights can last up to 90 seconds, in which time it should fly about 100 meters.
Sensors monitor aspects such as the height, movements, aerodynamic performance of the drone and how it reacts to gusts of wind.
The cold will also affect Ingenuity’s lithium-ion batteries, so keeping the drone warm at night is a big part of the project while being charged during the day via its solar panels.
“We have these 90 second flights, but then a lot of time is spent running the heating,” he said. “I joke that we are a heater that flies every now and then.”
The concept of using drones on robotic probes to explore the solar system is relatively new, and unlikely to be the last flight on another planet or moon.
NASA is already planning a more complex helicopter drone for Mars, and the proposed Dragonfly mission to Saturn’s moon Titan would launch in the late 1920s. It would deploy a full drone helicopter probe, equipped with scientific instruments, in the thick but non-breathing atmosphere there, where it is much easier to fly than on Mars.
Planetary scientist Lori Fenton of the Search for Extraterrestrial Intelligence Institute (SETI) in California, who studies sand dunes on Mars and the challenges facing robotic Mars rovers, said she recalled a scientific proposal 12 years ago that suggested a use a drone to study a field site somewhere in the western United States.
[Some] Panelists thought it absurd for someone to ask for funding to use ‘toys’ to do science, ”she said. “Since then, the UAV industry has exploded, and here we are – about to land a drone on Mars that will do exactly the kind of exploration that the review panel laughed at,” she said, referring to unmanned aerial vehicles.