Category Archives: Aerospace Engineering

Robotic probes on Mars

The Mars Science Laboratory (MSL) is a robotic probe on a mission to study Mars with international support. It has been achieving its goals by finding signs of habitable conditions that would have supported biological life improving our understanding of the kind of environment Mars once had. It has faced delays and setbacks, but will provide necessary experience for developing future manned missions to the planet. It will also likely continue on its journey for some time exploring the Martian surface. MSL is extending the depths of our understanding of the solar system and sits at the forefront of space exploration.

The path that Curiosity has followed since landing in 2012 (Grush, 2016).

The high-level goals of MSL set by NASA are to study the soil on the Martian surface for signs of biological life. They hope to achieve these goals by equipping the rover with instruments that can perform chemical analyses on soil samples collected from the Martian surface. It also has the auxiliary goals of testing new landing techniques that include more automation and autonomy on the part of the robotic probe, which proved successful with the landing of its single rover called Curiosity on August 6th, 2012 (Amos, 2012). MSL is achieving the goals NASA set for it by finding things like silica deposits, which are associated with environments conducive to microbial life (Chappell, 2015). Interesting to consider that silica is a compound of oxygen and silicon (Si), a semiconducting material used in transistors and integrated circuits. The interesting question is whether biological life forms could be based on an element other than carbon, and one such element considered by academics is silicon because of its similarities to carbon (“Could silicon be the basis for alien life forms, just as carbon is on Earth?”, n.d.). The Curiosity rover itself almost certainly has some silicon parts too. Curiosity also recently found boron, which was a positive sign, because of its water solubility (Grush, 2016). The boron is indicative of a lake that may have once existed in the Gale Crater.

The journey of the MSL robotic probe to Mars has not been without problems and critical moments of difficulty. It has, however, been a relatively calm journey overall in comparison to other unmanned missions. During its development, the rover’s launch had to be delayed multiple times because of engineering challenges and design problems with, among other things, its heat shield (Chang, n.d.). NASA did not think it would be a good idea to compromise the mission and decided to extend the rover’s development for two more years for further testing (Matson, 2008). Testing of the rover’s equipment also led to increased costs as a result of the delays and changes to the rover. Curiosity was actually designed with shutdown features that would protect the probe in certain hazardous situations that could destroy it. On several different occasions since landing, Curiosity has put itself into a safe mode before scientists rebooted the rover. These incidents were caused mostly by software problems including memory management (Lumb, 2016). If NASA had not been able to recover the rover, it would have clearly resulted in mission failure and would mean that its retirement could not be delayed any further.

The future of MSL has mixed projections, some positive and some not as positive. Curiosity has already outlived its original expected retirement date. Even after Curiosity is officially retired, its future will still be its legacy of discoveries also leaving a lasting impact on our future manned missions to Mars. However, Curiosity has already showed signs of aging as A.I. and robotics has continued on its exponential advance since 2012. Even worse, the rover hasn’t really found any real evidence that biological life once existed on the planet, one of its primary goals. This has led Astrobiologists to consider other novel ways of finding life on the red planet. They suggest that deeper subsurface analysis for life would be better than our current method of simply finding where water reservoirs and lakes were because we could find fossils as well as microbes in groundwater (David, 2017). It’s also true that these bodies of water probably moved around as a result of continental drift caused by the shifting of tectonic plates that may actually still be occurring.

In conclusion, I feel the Mars Science Laboratory mission has gone very well despite its shortcomings. The Curiosity rover has found some positive signs, such as elements like silica and boron, which could indicate an environment that would have supported life. It may also be beneficial if we incorporated other strategies for finding life on the red planet. Curiosity, like its predecessors, is still only the beginning of our journey to Mars.

References

Amos, J. (2012, August 06). Nasas Curiosity rover successfully lands on Mars. Retrieved June 23, 2017, from http://www.bbc.com/news/science-environment-19144464

Chang, A. (n.d.). Mars Science Laboratory faces technical problems. Retrieved June 23, 2017, from http://abcnews.go.com/Technology/story?id=4368824&page=1

Chappell, B. (2015, December 18). Curiouser And Curiouser: NASA’s Curiosity Rover Finds Piles Of Silica On Mars. Retrieved June 23, 2017, from http://www.npr.org/sections/thetwo-way/2015/12/18/460254072/curiouser-and-curiouser-nasas-curiosity-rover-finds-piles-of-silica-on-mars

Could silicon be the basis for alien life forms, just as carbon is on Earth? (n.d.). Retrieved June 23, 2017, from https://www.scientificamerican.com/article/could-silicon-be-the-basi/

David, L. (2017, May 09). The Search for Life on Mars Is about to Get Weird. Retrieved June 23, 2017, from https://www.scientificamerican.com/article/the-search-for-life-on-mars-is-about-to-get-weird/

Grush, L. (2016, December 14). NASA’s Curiosity rover finds more evidence that Mars was once habitable. Retrieved June 23, 2017, from https://www.theverge.com/2016/12/14/13939840/nasa-curiosity-mars-rover-habitable-planet-gale-crater-mount-sharp

Lumb, D. (2016, July 14). NASA’s Curiosity rover took a ‘safe mode’ nap this weekend. Retrieved June 23, 2017, from https://www.engadget.com/2016/07/07/nasa-s-curiosity-rover-automatically-shut-down-over-the-weekend/

Matson, J. (2008, December 4). Mars Science Laboratory rover delayed two-plus years. Retrieved June 23, 2017, from https://blogs.scientificamerican.com/news-blog/mars-science-laboratory-rover-delay-2008-12-04/

Landsat Remote Sensing Data

The Landsat project captures a wide variety of heterogeneous data about the surface of the Earth approximately every 16 days. Most of its satellites, including Landsat 7 and 8, are placed in sun-synchronous and near-polar orbits to accomplish this. Landsat imagery has been used to document the deforestation of the rain forests which has been crucial to understanding why it occurs. The imagery will prove beneficial in reforestation efforts brought on by wildfires in Oklahoma, Kansas, and the Okefenokee National Wildlife Refuge. Mapping glacier loss additionally helps us monitor climate change in remote areas where statistical anomalies defy global trends. The Landsat project offers a very high-resolution view of Earth’s environment.

Deforested areas (light green and pink) of the Amazon rain forest captured by Landsat between November 13th, 1986 (left) and October 30th, 2016 (“Monitoring Deforestation in the Amazon,” 2017).

One application of the remote sensing data collected by the Landsat project is to monitor the deforestation of the Amazon rain forest. The imagery collected by Landsat documents the deforestation that has been occurring over the past several decades. It is used to determine the reason for the deforestation which is primarily agricultural farming and cattle grazing. Deforestation anywhere is particularly problematic because plants and trees convert CO2 into carbohydrates which produce oxygen as a byproduct during photosynthesis (“The Carbon Cycle and Earth’s Climate,” n.d.). Destruction of these forests means that there’s less plants offsetting global carbon emissions in the atmosphere from industrialized nations as these areas become industrialized themselves. This is why world leaders have been taking steps with things like the Paris accord to set international agreements for climate emission reductions and mitigation. Interestingly, the agreements are considered so important that even countries like North Korea have praised them (Finnegan, 2017). Landsat tells a similar story of forest loss in Cambodia where a surge in land concessions has contributed to an accelerated rate of deforestation. The Okomu Forest has also been subject to the same industrial demands of large-scale rubber and oil palm plantations.

Another tangible application of the data is the monitoring of drought and wildfire conditions. Landsat 8’s data will be used in planning the reforestation of the Okefenokee National Wildlife Refuge after a wildfire that was ignited by lightning is contained. Infrared radiation band measurements of vegetation by Landsat will also assist with wildfires in Kansas and Oklahoma where 780,000 acres of farm and ranch land have been scorched. Understanding where these wildfires spread is necessary when assessing the damage caused to both wildlife ecosystems and human property. A lack of geological data would preclude strategizing containment efforts and planning evacuation routes.

The growth of Pio XI Glacier in the Southern Patagonia Icefield between October 4th, 1986 (left) and October 22nd, 2016 (“As Glaciers Worldwide Are Retreating, One Defies the Trend,” 2017).

What I felt was the most important application of the data was the monitoring of changing climates and ecosystems. It’s important to consider that humans have only been around for a fraction of the Earth’s existence and that the planet wasn’t always as habitable to biological life as it is today. The Landsat imagery has captured a wide array of changes to our planet’s climate over the decades which could have a profound impact on its habitability. Certain anomalies have been recorded such as the growth of the Pio XI Glacier that is defying global glacier trends of decreasing ice mass. However, supplemental data may be necessary, like the depth of the lakes it flows into, in order to determine why the glacier shows abnormal growth. This glacier may be important in understanding why other glaciers are melting. When glaciers melt they release trapped methane and other greenhouse gases that may contribute to global warming. Methane is a more potent greenhouse gas than carbon dioxide by as much as 86 times (Vaidyanathan, 2015). It is believed that as global warming progresses, more glaciers will melt, and the process becomes cyclical.

In conclusion, the Landsat project collects data that is essential to a lot of our most critical science research. The imagery collected tells us many stories about the changes occurring in our global environment from the deforestation of rain forests to wildfires, natural disasters, and the growth and shrinking of glaciers. It is for these reasons that I believe the USGS’s Landsat project has contributed positively to many applications of the scientific community.

References

As Glaciers Worldwide Are Retreating, One Defies the Trend [Online image]. (2017, May 18). Retrieved June 08, 2017, from https://remotesensing.usgs.gov/gallery/gallery.php?cat=3#582

Finnegan, C. (2017, June 7). North Korea blasts Trump as ‘silly,’ ‘ignorant’ over Paris Accord withdrawal. Retrieved June 08, 2017, from http://abcnews.go.com/International/north-korea-blasts-trump-silly-ignorant-paris-accord/story?id=47898345

Monitoring Deforestation in the Amazon [Online image]. (2017, May 18). Retrieved June 08, 2017, from https://remotesensing.usgs.gov/gallery/gallery.php?cat=3#710

The Carbon Cycle and Earth’s Climate. (n.d.). Retrieved June 08, 2017, from http://www.columbia.edu/~vjd1/carbon.htm

Vaidyanathan, G. (2015, December 22). How Bad of a Greenhouse Gas Is Methane? Retrieved June 08, 2017, from https://www.scientificamerican.com/article/how-bad-of-a-greenhouse-gas-is-methane/