NASA is sending a helicopter to the red planet, but it won't fly there on its own - it will be attached to the belly pan of the space agency's Mars Rover, lifting off in 2020.
The tiny autonomous rotorcraft will head to Earth's distant neighbour to demonstrate the viability and potential of heavier-than-air vehicles on another planet.
"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," NASA science mission directorate associate administrator Thomas Zurbuchen said.
The pint-sized aircraft weighs just 1.8 kilograms, has a fuselage about the size of a softball, and twin, counter-rotating blades that will zip through the thin Martian atmosphere at nearly 3000rpm - about 10 times the rate of similar craft on Earth.
But its light-weight construction was a challenge, and took the development team four years to design and test.
"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," Mimi Aung, Mars Helicopter project manager at NASA's Jet Propulsion Laboratory, said.
"To make it fly at that low atmospheric density, we had to scrutinise everything, make it as light as possible while being as strong and as powerful as it can possibly be."
It also has solar cells to charge its lithium-ion batteries, and a heating mechanism so it can endure the cold Martian temperatures after dark.
After the Rover lands on the Mars in 2021, the helicopter will be dropped onto the ground in a suitable spot, where it can charge its batteries and do some pre-launch tests.
Then, it will attempt to make its historic, autonomous first flight.
"We don't have a pilot and Earth will be several light minutes away, so there is no way to joystick this mission in real time," Ms Aung said.
"Instead, we have an autonomous capability that will be able to receive and interpret commands from the ground, and then fly the mission on its own."
The helicopter will fly up to a few hundred metres distance and up to three metres high.
If it is successful, it might pave the way for similar craft to act as low-flying scouts to help access parts of Mars not reachable by ground travel.
"The ability to see clearly what lies beyond the next hill is crucial for future explorers ... with the added dimension of a bird's-eye view from a 'Marscopter,' we can only imagine what future missions will achieve," Mr Zurbuchen said.
The Rover will perform geological tests, search for signs of ancient Martian life, and assess resources and hazards for future human explorers.
- ABC
