Weighing just 1.8 kilograms (4 pounds) of carbon fiber, flight-grade aluminum, silicon, copper, foil, and foam, NASA’s Mars Helicopter successfully completed its first rounds of test flights in January, demonstrating that the technology is ready to head to the Red Planet as soon as next year.
But flying a helicopter on another planet is a challenge completely different than those faced on Earth. For starters, the material must be able to withstand cold temperatures with nights dipping down as low as -90°C (-130°F) – not to mention a completely different atmospheric makeup and gravity conditions.
"The Martian atmosphere is only about one percent the density of Earth's," said MiMi Aung, project manager for the Mars Helicopter at NASA's Jet Propulsion Laboratory California, in a statement. "Our test flights could have similar atmospheric density here on Earth – if you put your airfield 30,480 meters (100,000 feet) up. So, you can't go somewhere and find that. You have to make it."
That’s where NASA’s Jet Propulsion Lab in southern California comes into play. Here, researchers created a 7.6-meter-wide (25-foot-wide) Flight Simulator capable of mimicking conditions on the Red Planet. A vacuum sucks out nitrogen, oxygen, and other gas and replaces it with carbon dioxide, the main component of Mars’ atmosphere. Accounting for gravity is another story.
"To truly simulate flying on Mars we have to take away two-thirds of Earth's gravity because Mars' gravity is that much weaker,” said test conductor Teddy Tzanetos. So, the team attached a motorized lanyard to the top of the helicopter in order to offload gravity via an uninterrupted tug equaling two-thirds of Earth’s gravity. This gravity offload system “performed perfectly” and maintained a 5-centimeter (2-inch) autonomous hover in what Tzanetos called a “heck of a first flight.”
The following day, a second flight in the vacuum chamber successfully flew at the same altitude for one minute.
"Gearing up for that first flight on Mars, we have logged over 75 minutes of flying time with an engineering model, which was a close approximation of our helicopter," said Aung. "But this recent test of the flight model was the real deal. This is our helicopter bound for Mars. We needed to see that it worked as advertised."
The Mars helicopter is set to launch from Cape Canaveral in July of 2020 and will reach the Red Planet roughly six months later aboard the Mars 2020 Rover, which will be conducting geological assessments to determine the habitability of Mars as well as look for signs of ancient Martian life and collect soil and rock samples. A few months after landing, the chopper will be deployed and test the first flights from the surface of another world.