Summary Reader Response 3

In the articles, "Mars 2020 mission Perseverance rover" (n.d.), and "NASA’s Self-Driving Perseverance Mars Rover ‘Takes the Wheel’" (2021), the National Aeronautics and Space Administration (NASA) documents the operation of the upgraded auto navigation system called AutoNav for the Perseverance rover to traverse the Martian surface for signs of ancient life along with locating and transporting sample collections of rock back to Earth for analysis. The article states that the AutoNav enables the rover to autonomously drive at faster speeds of up to 120 meters per hour while performing 3D mapping of upcoming terrain, hazard identification, and trajectory planning for obstacle avoidance, which consequently reduces the time taken to reach its destination as it can now travel through complex terrains instead of going around them. NASA also mentions that the AutoNav includes ENav which is an enhanced navigation software that aids in more accurate hazard detection of small, pointed rock protrusions which were undetected by the earlier version of AutoNav on the Curiosity rover and caused holes to be created on the wheels which hindered the rover's ability to navigate. 

The Perseverance rover's components such as AutoNav and visual odometry face situational challenges in helping the rover safely navigate the surface of Mars. However, other components such as the ENav can successfully aid the rover's navigation of Mars. 

The first issue is that the Perseverance rover cannot independently rely upon the AutoNav to trek across Mars which is indicated in the article, NASA (2021). This is due to the component still requiring human elements such as a team of specialists that provide additional guidance for purposes such as generating a navigation course as well as strategizing the rover's operations that include investigating unique terrestrial features along with procuring the necessary samples that it comes across, likewise such instructions are performed by the rover the day after they are sent as there is a radio signal delay between Earth and Mars.

Furthermore, the second issue is that the Perseverance rover can only utilize the visual odometry under specific environmental conditions for rover navigation. This is due to the component's function depending on the periodic images captured by cameras during locomotion. The quality of these images is largely affected by environmental factors such as terrains that are not flat, inadequate, or have direct sunlight, and weather patterns such as dust storms, high winds, etc. Hence, these environmental factors as stated in the article, Aqel, M.O., Marhaban, M.H., Saripan, M.I., Ismail, N. (2016), affect the system's accuracy as they can lead to an incorrect estimation of the resulting trajectory for the rover, and therefore negatively affects the time and efficiency required to reach the rover's targeted distance.

Despite the challenges faced by the AutoNav and visual odometry, the Perseverance rover still utilizes these components and other components such as the ENav to safely navigate over the Martian surface. Although the AutoNav requires human elements, it can still autonomously drive and perform 3D mapping of upcoming terrain, hazard identification, etc. Whereas, visual odometry is another system that assists in the rover's safe navigation over Mars as it maintains a record of the distance it has traversed from one location to the next to reach its targeted distance efficiently. Thus, when the rover needs it to backtrack its path, it can refer to the former records to avoid potentially dangerous areas that it has previously encountered. The ENav and a sturdier design for the wheel structure are utilized due to the Martian surface being comprised of rougher ground containing numerous small, sharp, and pointy rocks that are detrimental in maintaining the structural integrity of the wheels and the rover itself, which is shown in the article, NASA (2021). Therefore, the ENav software is used for the detection of such hazards in conjunction with wheels themselves being modified to incorporate 48 treads with a slightly wavy design to aid in the traction and durability of the rover. 

In conclusion, the Perseverance rover utilizes diverse components such as AutoNav, ENav, and visual odometry in its navigation system to overcome a majority of challenges posed by the environmental conditions on Mars, and henceforth efficiently support the rover's safe navigation over the Martian surface.

Aqel, M.O., Marhaban, M.H., Saripan, M.I., Ismail, N. (2016, October 28). Review of visual odometry: types, approaches, challenges, and applications. SpringerPlus 5, 1897. 

https://springerplus.springeropen.com/articles/10.1186/s40064-016-3573-7

National Aeronautics and Space Administration. (n.d.). Mars 2020 mission Perseverance rover. https://mars.nasa.gov/mars2020/

National Aeronautics and Space Administration. (2021, Jul 2). NASA’s Self-Driving Perseverance Mars Rover ‘Takes the Wheel’. https://www.nasa.gov/feature/jpl/nasa-s-self-driving-perseverance-mars-rover-takes-the-wheel