A Drone Made History - First Flight on Mars

Astronomy and Astrophysics - Part 2

May 09, 2021

Greetings, fellow scientist.

While we are all stuck in lockdown for who even knows how long, NASA, the US space agency again made history in space exploration. Except this time, they have found their eureka moment in the atmosphere of another planet- Mars, by accomplishing power-controlled flight on another world for the first time.

What started as a dream, became reality on April 19th, 2021 at around 4:00 PM IST/ 6:30 AM EST for the Ingenuity helicopter team. When downlink fetching data and processing mission specialists gave the confirmations of obtaining data from the helicopter 289 million kilometres away, it displayed outstanding snapshots captured by the Perseverance rover and helicopter itself. So, how did they get to this milestone? Why this achievement is so special? Let me explain.

Mars 2020 Mission

Earlier this year 2021, on February 18th, the space agency dropped off their fifth rover, as a part of their Mars 2020 Mission, known as Perseverance on its surface. The primary mission of Perseverance is to look for previous signs of life. With a suite of science instruments aboard, the rover was not alone. Tucked away in its belly was a small helicopter (1.8 kg) or a rotorcraft named Ingenuity. It weighs even less than a two-litre bottle of soda. Early this month, on April 4th, NASA’s Jet Propulsion Laboratory (JPL) confirmed its touchdown on the surface of Mars. This moment was like a mama bird feeding a baby bird, before surviving on its own.

Drone’s Specifications

What makes this technology demonstration even special?

Its cutting-edge enginery. It is not just a box with four legs attached to two carbon fibre rotor blades and atop a radio antenna and a solar panel, but it has a very fast and clever processor inside its guts.
Mars does not really have an atmosphere. It is about 1% as thick as the Earth’s. As a result, blades must spin very fast (2000-3000 RPM) as compared to helicopters working on Earth (400-500 RPM).
Mars really likes to kill our robots (Viking-1, Viking-2) as it is really cold, dusty and not shielded from radiation from space.
The team wants it to operate for as long as 30 Martian days. So basically, this remarkable and one of its kind flyer is not designed to fly all over Mars. In fact, it is designed to fly for short bursts of about 30-90 seconds- five times at most.
Most importantly, we know that rovers cannot get everywhere as they are built like cars. If we want them to get into a rocky outcrop or the side of a mountain on Mars, they have no hope. However, a drone can do that.

7 Things Ingenuity had to Tackle

Ingenuity had some major challenges to overcome before heading to the skies of Mars which are listed below:

Establish communication with the rover and flight controllers on Earth.
Ensure autonomous heat control for protection against intensely cold Martian nights. Temperatures are as low as minus 130 degrees Fahrenheit, or minus 90 degrees Celsius on Mars.
Charging autonomously using its solar panel.
Monitoring daily power consumption, solar energy, and battery levels.
Unlock rotor blades.
Spin up rotor blades for the first time on Mars (at a slow speed) while still on the surface.
Full high-speed spin test of its rotors (~2400 RPM) for the first time on Mars while remaining on the surface.

The Glitch before the First Flight

On 49th Martian day (sol), NASA caught wind that something might not be right. Ingenuity, while getting ready for a high-speed spin test of its rotors, did not transition from pre-flight check-out mode to its first flight mode as expected. When this happened, Ingenuity behaved exactly as it was programmed to. It devised itself into sleep mode had it been in flight. Moreover, the onboard logic did not recognize the flight control computers as healthy and functional despite exhibiting stable critical functions like communications, thermal control, and power. So, to get Ingenuity’s onboard computers to relay information with each other in an orderly manner again, the JPL team decided to send the helicopter a software update from the Earth.

Overcoming the challenge

The process for updating the ingenuity software is conceptually similar to a user downloading a software update from an operating system supplier and installing it on a personal computer. In contrast, instead of being downloaded directly by the user, Ingenuity’s software update has to funnel between several different computers linked across the vastness of space called The Deep Space Network (DSN).

DSN is the communication network of giant radio antennas dotted around the Earth. It helps NASA and other space agencies transmit information to and from planetary spacecraft. Thereupon, the following procedures for sending an update were followed:

Designing, validating, and exercising the software on testbeds that are computationally identical to the flight systems.
Compression and separation of designed software into pieces for its journey through DSN.
The pieces from the software load were sent from JPL, via DSN, to one of the satellites currently orbiting Mars.
Then, it relayed down the pieces to the Perseverance rover on the surface of Mars where they were reassembled into a consolidated software package.
After the software update’s safe landing in perseverance hands, it was finally passed along to Ingenuity via Helicopter Base Station.
It is a dedicated controller in the rover which collects, stores, and configures data communications between the rover and the helicopter.
Finally, Ingenuity installed the software update to its computers and performed a reboot itself.

Fortunately, Ingenuity proved ingenious and all went according to the plan of this new update. Thus, enabling one of its core milestones- the first powered controlled flight on another planet, it vertically lifted itself in the air for about 10 seconds by spinning its blades at 2500 RPM. The data received after 4 hours of actual flight on the red planet (again with the help of DSN) and its processing displayed impressive images and a plot of altimeter indicating successful lift-off.

In addition to that, now, we can tell a robot to fly on its own in another world. And this event is indeed a Wright Brothers’ Moment for the Ingenuity team because they will now be credited with inventing, building, and flying the world’s first successful aircraft on another planet.