An autonomous Mars Helicopter is set to form part of Nasa’s next mission to the red planet, scheduled to launch in July 2020.
In development at Nasa’s Jet Propulsion Laboratory (JPL) since 2013, the helicopter will be attached to the belly pan of the Mars 2020 rover and deployed in a suitable location once the rover touches down. Twin counter-rotating blades will spin at almost 3,000 rpm, designed to counteract Mars’ thin atmosphere. In contrast, helicopters on Earth typically operate at around 300 rpm.
“The altitude record for a helicopter flying here on Earth is about 40,000 feet,” said Mimi Aung, Mars Helicopter project manager at JPL. “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 scrutinise everything, make it as light as possible while being as strong and as powerful as it can possibly be.”
Weighing in at just 1.8kg, the Mars Helicopter has a fuselage roughly the size of a softball, as well as solar cells to charge its lithium-ion batteries and a heating mechanism to keep it warm through the cold Martian nights. Once deployed and its batteries are charged, multiple tests will be performed before controllers on Earth command the Mars Helicopter to take its first autonomous 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,” said Aung. “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.”
According to Nasa, the full 30-day test campaign will include up to five flights of incrementally longer distances and durations, ranging up to a few hundred meters and as long as 90 seconds. On its first flight, the helicopter will make a short vertical climb to 3 metres where it will hover for about 30 seconds. Flight data will be relayed back to Earth via the rover, and the helicopter could also help inform which direction the ground vehicle should travel.
“The ability to see clearly what lies beyond the next hill is crucial for future explorers,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “We already have great views of Mars from the surface as well as from orbit. With the added dimension of a bird’s-eye view from a ‘marscopter,’ we can only imagine what future missions will achieve.”
The Mars Helicopter is considered a high-risk, high-reward project. If unsuccessful, the Mars 2020 mission will not be impacted. However, if it does work, helicopters may have a real future in interplanetary exploration. The Mars 2020 mission is due to arrive at the red planet in February 2021.