Reader's Response Draft 3

In the publication, “Mars Helicopter Technology Demonstrator”, Balaram (2018) described the key attributes of Mars Helicopter, launched with Perseverance Mars rover, Ingenuity. Ingenuity was designed as a prototype to determine whether powered flight is possible on Mars. One of the key attributes mentioned by the author is the rotor system. The system consists of swashplates, propulsion and servo motors, Chinese weights, pitch links and dust boots. Due to the thin air in Mars's atmosphere, the rotor uses a 1.21m diameter coaxial counter-rotating rotors with a rigid motor that has a rate of 2800rpm to provide lift for the helicopter. Another attribute mentioned by the author is the camera system. The system consists of a wide-angle 0.3-megapixel navigation camera and a 12-megapixel color camera. The navigation camera is used to provide a velocity estimate using visual features, tracked from frame to frame, extracted from the images.

With the help of its rotor system and navigation system, Ingenuity will be able to autonomously explore parts of Mars that are unreachable to rovers and astronauts.

Ingenuity's rotor system is equipped with a rigid motor that has a rate of 2800rpm to overcome challenges, such as the atmosphere and gravity in Mars, which differs from Earth, to lift the helicopter. It was impossible to fully recreate those aspects here on Earth which made it difficult to test the helicopter's aerial abilities. Ingenuity's first successful flight has made history as the first powered flight in Mars and unlocked new possibilities to the exploration of Mars. Ingenuity has achieved a flight altitude of 12m during its 10th flight (Tzanetos, 2021), and will soon be able to fly to high elevated grounds of up to 8km, previously deemed not possible (Withrow, 2020). Similar prototypes like Ingenuity have been developed after Ingenuity's success flight. For example, China has developed its own prototype Mars rotorcraft (Jones, 2021). This shows that Ingenuity has made a significant impact in the Aeronautics industry by setting the expectations of a helicopter in space.

Ingenuity's navigation system also includes a navigation camera, which assists in the movement of the helicopter. Ackerman (2021) mentioned that Ingenuity is half autonomous. A set of direction guidelines is uploaded into the helicopter before take-off and once Ingenuity is in space, it will fly autonomously according to the guidelines. To help navigate the helicopter during autonomous flight, the navigation camera, located at the lower sensor assembly, obtains images at 10 frames/sec and compares it with one another to trace the relative position and figure out the direction and speed (Balaram, 2018). Due to the distance between Mars and Earth, which results in delay of signals, Ingenuity cannot be controlled from Earth. Therefore, the navigation system is a critical aspect for a helicopter to fly autonomously on Mars.

Despite Ingenuity's multiple success flights in Mars, the Ingenuity is not designed for changing seasonal conditions. The air on Mars is thinner during changing seasonal conditions which means that the rotors need to turn faster to overcome the thin air and lift the helicopter. However, Grip mentioned that making the rotors spin at a faster rate may "cause damage to hardware and lead to a deterioration in sensor readings needed by the flight control system" (Howell, 2021).

In conclusion, the success of Ingenuity's flight is a new milestone to the mission of exploring Mars to determine the possibility of human habitation on the planet. Ingenuity will be used as a guideline to build and create rotorcrafts to assist in future robotic missions by scouting and imaging challenging terrains or future crewed missions like helping an astronaut pick up a tool at the base. The mission of exploring the solar system is endless and Ingenuity is just the beginning. 

References

Ackerman, E. (2021) How NASA Designed a Helicopter That Could Fly Autonomously on Mars. 
https://spectrum.ieee.org/nasa-designed-perseverance-helicopter-rover-fly-autonomously-mars

Balaram, J., Canham, T., Duncan, C., Golombek, M., Grip, H., Johnson, W., Maki, J., Quon, A., Stern, R., & Zhu, D. (2018). Mars Helicopter Technology Demonstrator 
https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_AIAA2018_0023.pdf

Howell, E. (2021). Flying on Mars getting tougher as Ingenuity helicopter gears up for 14th hop. 
https://www.space.com/mars-flying-harder-ingenuity-helicopter-14th-flight

Jones, A. (2021). China is developing its own Mars helicopter. SpaceNews 
https://spacenews.com/china-is-developing-its-own-mars-helicopter/

Tzannetos, T. (2021). Aerial Scouting of ‘Raised Ridges’ for Ingenuity’s Flight 10. Mars NASA.  https://mars.nasa.gov/technology/helicopter/status/316/aerial-scouting-of-raised-ridges-for-ingenuitys-flight-10/

Withrow, S., Johnson, W., Young, L., Cummings, H., Balaram, J. & Tzanetos, T. (2021). An Advanced Mars Helicopter Design. ASCEND. 
https://arc.aiaa.org/doi/abs/10.2514/6.2020-4028