We are, obviously, referring to the Mars Helicopter Ingenuity, which, on 18th January 2024, made its final, 72nd flight over the surface of the Red Planet. The flight which marked the end of its Martian sky adventure, due to damage suffered by the helicopter during landing. Almost one year later, on 11th December 2024, NASA Jet Propulsion Laboratory (JPL) announced on its website that their engineers, in collaboration with specialists from AeroVironment, are completing a detailed analysis of Ingenuity’s last flight to clarify what exactly happened then.
The Mars Helicopter Ingenuity, which was the first aircraft to fly on a planet other than Earth, was designed as a technology demonstrator intended to perform up to five experimental test flights in thirty days. Nevertheless, the Mars Helicopter exceeded the most daring expectations of its developers and the mission control team, eventually operating for almost three years, making as much as seventy-two flights during this time and flying more than thirty times further than planned, accumulating a total of more than two hours of flight time.
The Flight 72 was planned as a short vertical hop to evaluate the Ingenuity flight systems and take photographs from above of the area the helicopter was in. The flight data showed that the Ingenuity climbed to an altitude of 40 feet (12 metres) as planned, hovered and took photographs. Then, after nineteen seconds the rotorcraft began its descent, and after thirty-two seconds from take-off the helicopter landed on the Martian surface again. The landing was followed by a breakdown in communications with the NASA Helicopter Team on Earth. The next day, mission control re-established communications and photographs taken by the Perseverance rover – the Ingenuity’s wheeled companion – six days after the flight, revealed that the rotorcraft had suffered severe damage to its rotor blades.
‘When running an accident investigation from 100 million miles away, you don’t have any black boxes or eyewitnesses. While multiple scenarios are viable with the available data, we have one we believe is most likely: Lack of surface texture gave the navigation system too little information to work with.’ – said Håvard Grip of NASA Jet Propulsion Laboratory, the first pilot of the Mars Helicopter Ingenuity.
The vision navigation system of the Ingenuity was designed to track visual features on the well-textured (rocky) but flat terrain of the Martian surface using a downward-facing camera. This tracking capability, although limited, was more than enough to complete the originally planned five flights of the Ingenuity. However, by flight 72, the rotorcraft had travelled significantly away from its initial location and was already in the region of Jezero crater, filled with steep, relatively featureless sand ripples.
One of the main requirements of the Mars Helicopter navigation system was to provide estimated speeds that would enable the rotorcraft to land within a tight range of vertical and horizontal speeds. The transmitted data from Flight 72 showed that about twenty seconds after take-off, the navigation system could not find enough tracking elements on the surface.
Post-flight imagery indicates that the resulting navigational errors caused excessive horizontal speed on landing. According to the most probable scenario, the Ingenuity hit hard on the slope of a sand ripple which caused the aircraft to pitch and roll. And the rapid change in orientation caused stress on the rapidly spinning rotor blades, exceeding their design limits. That, in consequence, caused all four rotor blades of the Mars Helicopter to break at their weakest point – about a third of the way from their tips. The damaged blades created excessive vibration of the entire rotor resulting in one of the blades breaking out completely. That finally led to generation of excessive power demand in the aircraft systems, resulting in loss of communications with the Mars Helicopter Team.
Although the seventy-second flight of the Ingenuity permanently grounded the helicopter and caused the end of its history-making mission on Mars, the rotorcraft kept sending weather and avionics test data to the Perseverance rover about once a week. The weather information could benefit future exploration missions to the Red Planet. Avionics data acquired thanks to the Ingenuity are already being used by engineers working on future designs of aircraft and other vehicles intended to explore Mars.
‘Because Ingenuity was designed to be affordable while demanding huge amounts of computer power, we became the first mission to fly commercial off-the-shelf cell phone processors in deep space. We’re now approaching four years of continuous operations, suggesting that not everything needs to be bigger, heavier, and radiation-hardened to work in the harsh Martian environment.’ – said the Mars Helicopter Ingenuity project manager Theodore Tzanetos.
Currently, NASA engineers, inspired by the longevity and durability of the valiant Ingenuity, are testing a smaller, lighter avionics that could be used in vehicles designed for the needs of Mars Sample Return mission. These data are also helpful for engineers studying how a future Mars rotorcraft could look and operate.
During a briefing held on Wednesday, 11th December 2024, at the annual meeting of the American Geophysical Union in Washington, Theodore Tzanetos presented details about the Mars Chopper rotorcraft, one of the concept aircraft being developed by him and other alumni of the Ingenuity. According to the project, the Mars Chopper is expected to be about twenty times heavier than the first Martian helicopter and is expected to be able to fly with several kilograms of scientific equipment, autonomously exploring remote areas of the Mars surface as well as travel up to 2 miles (3 kilometres) per day. By comparison, the longest flight of the Ingenuity was 2310 feet (704 metres).
‘Ingenuity has given us the confidence and data to envision the future of flight at Mars.’ – emphasized Tzanetos.
Detailed evaluation of the Mars Helicopter Ingenuity final flight should be published in the nearest future as a NASA technical report. The findings of the report are expected to benefit future robotic helicopters on Mars, as well as other aircraft designed to operate in the future on other planets.
If you want to know more about the Mars Helicopter Ingenuity, additional information can be found in our previous articles listed below:
- 19 April 2021 – first flight of the Mars Helicopter Ingenuity
- Ingenuity Mars Helicopter completes its 50th flight
- Historic journey of Ingenuity, NASA Mars Helicopter has come to end
Cover photo: NASA’s Ingenuity helicopter can be seen on Mars as viewed by the Perseverance rover’s rear Hazard Camera on April 4, 2021, the 44th Martian day, or sol of the mission. (Photo by NASA – PIA24541)
In this article, press releases and other materials of the National Aeronautics and Space Administration were used. All photos and quotations © National Aeronautics and Space Administration.
