Published : Saturday, March 30, 2019 | 5:34 AM
Engineers at the Jet Propulsion Laboratory in Pasadena conducted the first-ever test flight of NASA’s Mars Helicopter in late January, as part of a rigorous verification process before the flight model could be certified as capable of flying in the Martian atmosphere.
JPL personnel flew the helicopter inside the lab’s Space Simulator, a 25-foot-wide vacuum chamber where much of the nitrogen, oxygen and other gases have been sucked out, and in their place was injected carbon dioxide, the chief ingredient of Mars’ atmosphere.
“The Martian atmosphere is only about one percent the density of Earth’s,” said MiMi Aung, project manager for the Mars Helicopter at JPL. “Our test flights could have similar atmospheric density here on Earth – if you put your airfield 100,000 feet up. So you can’t go somewhere and find that. You have to make it.”
The JPL team had earlier conducted flights of an engineering model of the helicopter in the same chamber.
“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,” Aung said. “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.”
All of the preparation is geared towards February 2021, when the Mars Helicopter, weighing no more than four pounds, will reach the Red Planet under the belly of the Mars 2020 rover. A few months later, it will be deployed and test flights, up to 90 seconds long, will begin – the first from the surface of another world.
Mars 2020 will launch in July 2020 on a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida.
Much of the testing the flight model is going through will help JPL and NASA engineers to demonstrate how the aircraft can operate on Mars, especially how it performs at Mars-like temperatures, which could be as low as minus 130 degrees in the night.
The test also included finding out not only how the helicopter could fly in the extremely thin Martian atmosphere, but also whether it could be stable considering that Mars’ gravity is equivalent to only two-thirds of Earth’s.
To simulate Martian gravity, the team attached a gravity offload system – a motorized lanyard attached to the top of the helicopter – to provide an uninterrupted tug equivalent to the approximated gravity on Mars.
“The gravity offload system performed perfectly, just like our helicopter,” Teddy Tzanetos, test conductor for the Mars Helicopter at JPL, said. “We only required a two-inch hover to obtain all the data sets needed to confirm that our Mars helicopter flies autonomously as designed in a thin Mars-like atmosphere; there was no need to go higher. It was a heck of a first flight.”
The first flight of the Mars Helicopter was followed up by a second in the vacuum chamber the next day, logging in a grand total of one minute of flight time at an altitude of 2 inches, JPL said.
“The next time we fly, we fly on Mars,” Aung said. “Watching our helicopter go through its paces in the chamber, I couldn’t help but think about the historic vehicles that have been in there in the past. The chamber hosted missions from the Ranger Moon probes to the Voyagers to Cassini, and every Mars rover ever flown. To see our helicopter in there reminded me we are on our way to making a little chunk of space history as well.”
JPL manages both the Mars 2020 rover development and the Mars Helicopter project for NASA’s Science Mission Directorate in Washington, DC.