Years & years of hard work came to fruition when Ingenuity took its incredible first flight on another planet, Mars. On April 19th, 2021, history was made. Ingenuity proved, autonomous, powered controlled flight was possible on another planet [1]. The mission was to fly in the thin Martian air, which is just about 1% of Earth’s atmospheric pressure was a success and the scientists have been bold enough to try three times, with each time Ingenuity has flown higher and longer. The success of these flights is steadily providing us the confidence and hope of more successful aircraft missions to other planets. The data provided by the Ingenuity flights is crucial for future drone designs and understanding the geology of the Mars. Ingenuity is complementing Perseverance with its ability to fly directly over craters and obstacles and provide valuable images something that Perseverance can’t do. It is a technological feat, surpassing that of any flight attempted so far.

 Some of the challenges facing the mission were:

  1. To perform an autonomous powered flight in the thin Martian atmosphere.

Even though Mars gravity is about one third of the Earth, it’s atmosphere is just 1% of Earths’ and therefore, flying on Mars would be equivalent to flying at around 100,000 feet on Earth – more than twice the height any helicopter has flown before. To generate enough thrust, propeller blades would have to spin at around 2500 revolutions per minute which is five times faster than any helicopter blades on Earth. However, the problem with blades potentially spinning faster than the speed of sound is that it will create aerodynamics and transonic flows which can disrupting the lift provided to the aircraft and so the rotors speed was fixed to maximum of 0.7 times the speed of sound. [7] Furthermore, it would have to fly completely by itself. A signal travelling at the speed of light would take 20 minutes for it to just reach the rover. Another 20 minutes would be needed until a return signal would get to Earth. As a result, trying to control its flight on Mars would be simply impossible, the helicopter would have to deal with any problems it encounters by itself.

 

2. Extremely strong and light.

Nasa’s chief Mars helicopter chief engineer Bob Balram explains that the rocket launch vibrations are about 60 G forces, equivalent to 60 times the gravity of the Earth.[8] This caused problems as the helicopter has to be strong enough to withstand these forces, let alone the immense forces when landing. A simple solution to this would be to add more material, but this means that the helicopter is now much heavier and so more power would be needed to lift the aircraft. If more power is required, this means more weight once again- a seemingly never-ending cycle. As a result, a balance needed to be struck, the lightest and most suitable materials for the job needed to be chosen whilst also trying to optimise the thickness and shape of materials to maximise structural integrity.

 

  1. Charging and surviving the intense Martian cold night up to -100°C

A major problem for the tiny Ingenuity helicopter is fending for itself. Due to its limited size, everything inside it must be crammed into the smallest of spaces. It’s batteries, heaters, communication systems all of which are vitally important, must also remain compact and extremely energy efficient. The helicopter will have to fend for itself, charging up its own batteries with its solar panels with no help from humans on Earth or even Perseverance. Moreover, it would have to keep itself warm in the cold, -100°C nights so that its electronics don’t freeze.

Ingenuity is an engineering marvel with a body weighing meagre 1.8kg and is only 19 inch tall with rotors width of 1.2 meters. [2,5] It also has solar panels that charge the Lithium-ion batteries, providing enough energy for one 90-second flight per Martian day.[5] Ingenuity is designed to be like a helicopter with twin blade propellers rather than a stable drone with four rotors. The propellers spin in opposite direction, the primary reason for this is that the top propeller collects a lot of air and bottom counter rotating propeller pushes the air down to generate even more upward thrust. Even though Mars’ gravity is one third of Earth, each propeller needs to run at 2500 rpm to get airborne, five times the speed of a normal helicopter.

Ingenuity captures images ten times the resolution of orbital images with its two zoomable cameras. [11] The downward facing navigation black and white framing camera captures and compares many images per second besides keeping track of its position and landing. This information is combined with its LIDAR altimeter to track the lateral motion for autonomous flight control and guidance. The second horizontal facing terrain camera captures 13 mega pixel coloured images towards the horizon for aesthetic purposes [9].

Without its thermal insulation, Ingenuity would freeze and would be unable to fly as temperature on Mars drop to -100°C at night. Thermal insulation is hugely important aspect and so the batteries are kept in centre of the helicopter surrounded by electronic circuit boards, further encapsulated with a shell containing CO2 gas, a greenhouse gas that further helps to keep it warm.

Ingenuity also has to have enough battery power for it to make meaningful flights. It has a battery of approximately 40-watt hours which is equivalent to the battery of three mobile phones. Due to the low temperatures on Mars around two thirds of the battery power is needed to keep the electronics and sensors warm.  This leaves the vehicle with only one third of battery available for the flight.

Ingenuity’s latest achievements:

  1. On the historic date of Mon 19 Apr 21 the craft completed its first flight by rising 3 meters above ground and hovering for around 30 seconds. [4]
  2. On Thu 22 April, the vehicle successfully completed its 2nd flight by hovering at maximum altitude of 5 meters for a longer duration and even completed lateral movements. [10]
  3. Three days later Sunday, April 25, 2021 the helicopter took to its 3rd flight. It rose to 5 meters and later moved laterally 50 meters before returning to original position.  [6]
  4. Nasa has planned many for flights soon with increasing levels of difficulty which will provide crucial data for future missions.

This is just the start of the interplanetary aircraft mission for NASA and an incredible engineering feat that has paved a way for a new era of exploration of space for generations to come. The next one to look forward to is Dragonfly, NASA’s drone for Titan.[3]

 

References:

[1]NASA- Mars Helicopter/Ingenuity https://mars.nasa.gov/files/mars2020/MarsHelicopterIngenuity_FactSheet.pdf

[Accessed 30/4/21]

[2] National Geographic- NASA Mars helicopter makes history as first vehicle to fly on another planet-published 19/4/21 https://www.nationalgeographic.com/science/article/nasa-mars-helicopter-makes-history-as-first-vehicle-to-fly-on-another-planet

[Accessed 30/4/21]

[3] SPACE.com- More Mars helicopters? NASA is already thinking about Ingenuity’s successors https://www.space.com/nasa-mars-helicopter-ingenuity-successors

[Accessed 30/4/21]

[4]NewScientist- NASA’s Ingenuity craft makes first ever helicopter flight on Mars- published 19/4/21 https://www.newscientist.com/article/2274956-nasas-ingenuity-craft-makes-first-ever-helicopter-flight-on-mars/

[Accessed 30/4/21]

[5] NASA https://mars.nasa.gov/technology/helicopter/#Tech-Specs

[Accessed 30/4/21]

[6]NASA-We Are Prepping for Ingenuity’s Third Flight Test- published 23/4/21 https://mars.nasa.gov/technology/helicopter/status/295/we-are-prepping-for-ingenuitys-third-flight-test/

[Accessed 30/4/21]

[7] Scientific American- NASA’s Ingenuity—the First Ever Off-World Helicopter—Is Set for a ‘Wright Brothers Moment’ on Mars- published 27/7/21 https://www.scientificamerican.com/article/nasas-ingenuity-the-first-ever-off-world-helicopter-is-set-for-a-wright-brothers-moment-on-mars/

[Accessed 30/4/21]

[8] THE ROBOTREPORT- Q&A: Ingenuity Mars Helicopter chief engineer Bob Balram- published 18/2/21 https://www.therobotreport.com/ingenuity-mars-helicopter-chief-engineer-bob-balaram/

[Accessed 30/4/21]

[9] NASA- Small Steps, Giant Leaps: Episode 53, Ingenuity Mars Helicopter-published 9/2/21 https://www.nasa.gov/mediacast/small-steps-giant-leaps-episode-53-ingenuity-mars-helicopter

[Accessed 30/4/21]

[10] NASA- NASA’s Ingenuity Mars Helicopter Logs Second Successful Flight- published 22/4/21 https://www.nasa.gov/feature/jpl/nasa-s-ingenuity-mars-helicopter-logs-second-successful-flight

[Accessed 30/4/21]

[11] Wikipedia- Ingenuity (helicopter) https://en.wikipedia.org/wiki/Ingenuity_(helicopter)

[Accessed 30/4/21]

IMAGES 

NASA- Ingenuity’s First Black-and-White Image From the Air-published 19/4/21 https://www.nasa.gov/image-feature/jpl/ingenuity-s-first-black-and-white-image-from-the-air

[Accessed30/4/21]