At present, there are over a dozen robotic missions exploring the atmosphere and surface of Mars. These include, among others, the Curiosity rover, the Opportunity rover, the Mars Orbiter Mission (MOM), the Mars Reconnaissance Orbiter (MRO), the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter, and the soon-to-arrive InSight Lander. In the coming decade, many more missions are planned.
For instance, NASA plans to expand on what Curiosity has accomplished by sending the Mars 2020 rover to conduct a sample-return mission. According to a recent announcement issued by NASA, this mission will also include the Mars Helicopter – a small, autonomous rotorcraft that will demonstrate the viability and potential of heavier-than-air vehicles on the Red Planet.
As NASA Administrator Jim Bridenstine declared in a recent NASA press release, this rotocraft is in keeping with NASA’s long-standing traditions of innovation. “NASA has a proud history of firsts,” she said. “The idea of a helicopter flying the skies of another planet is thrilling. The Mars Helicopter holds much promise for our future science, discovery, and exploration missions to Mars.”
U.S. Rep. John Culberson of Texas echoed Bridenstine statement. “It’s fitting that the United States of America is the first nation in history to fly the first heavier-than-air craft on another world,” he said. “This exciting and visionary achievement will inspire young people all over the United States to become scientists and engineers, paving the way for even greater discoveries in the future.”
The Mars Helicopter began as technology development project at NASA’s Jet Propulsion Laboratory (JPL), where it spent the past four years being designed, developed, tested and retested. The result of this is a football-sized rotorcraft that weights just under 1.8 kg (four pounds) and relies on two counter-rotating blades to spin at a rate of almost 3,000 rpm (10 times the rate of a helicopter here on Earth).
As Mimi Aung, the Mars Helicopter project manager at JPL, indicated:
“The altitude record for a helicopter flying here on Earth is about 40,000 feet. The atmosphere of Mars is only one percent that of Earth, so when our helicopter is on the Martian surface, it’s already at the Earth equivalent of 100,000 feet up. To make it fly at that low atmospheric density, we had to scrutinize everything, make it as light as possible while being as strong and as powerful as it can possibly be.”
This concept is ideal for navigating through Mars’ thin atmosphere, where the mean surface pressure is about 0.6% that of Earth’s at sea level (0.60 kPa compared to 101.3 kPa). This low-flying helicopter would not only be able to increase the range of a rover, it will be able to explore areas that the rover would find inaccessible. As Thomas Zurbuchen, the Associate Administrator for NASA’s Science Mission Directorate, explained:
“Exploring the Red Planet with NASA’s Mars Helicopter exemplifies a successful marriage of science and technology innovation and is a unique opportunity to advance Mars exploration for the future. After the Wright Brothers proved 117 years ago that powered, sustained, and controlled flight was possible here on Earth, another group of American pioneers may prove the same can be done on another world.”
Other capabilities that make it optimized for Mars exploration include lithium-ion batteries, solar cells to keep them charged, and heating mechanisms that will keep it warm during Martian nights – where average temperatures can get as low as 210 K (-63 °C; -82 °F) around the mid-latitudes. In addition, the helicopter is programmed to fly autonomously, since it cannot be flown in real-time (given the distances involved).
Commands will be issued from controllers on Earth, using the rover as a relay, who will instruct the helicopter to commence flight once it is ready to deploy. This will begin shortly after the rover arrives on the planet (which is expected to happen by February 2021) with the helicopter attached to its belly pan. The rover will then select a location to deploy the helicopter onto the ground.
After it is finished charging its batteries and a series of pre-flight tests are performed, controllers on Earth will relay commands to the Mars Helicopter to commence its first 30-day flight test campaign. This will include up to five flights that will take it to increasingly greater distances from the rover (up to a few hundred meters) for longer periods of time (up to 90 seconds).
On its first flight, the helicopter will make a short vertical climb to 3 meters (10 feet) where it will hover for about 30 seconds. Once these tests are complete, the Mars Helicopter will assist the rover as it conducts geological assessments and determines the habitability of its landing sight. The purpose of this will be to search for signs of ancient life on Mars and assesses the natural resources and hazards for future missions involving human explorers.
The rover will also conduct the first-ever sample-return mission from Mars, obtaining samples of rock and soil, encasing them in sealed tubes, and leaving them on the planet for future retrieval by astronauts. If all goes well, the helicopter will demonstrate that low-flying scouts and aerial vehicles can be a valuable part of any future missions. These will likely include robotic missions to Saturn’s largest moon, Titan, where researchers are hoping to explore the surface and atmosphere using helicopter (such as the Dragonfly concept).
The Mars 2020 mission is expected to reveal some very impressive things about the Red Planet. If the helicopter proves to be a viable part of the mission, we can expect that additional information and images will be provided from locations that a conventional rover cannot go. And in the meantime, be sure to enjoy this animation of the Mars Helicopter in action, courtesy of NASA-JPL:
Further Reading: NASA