An Exploration of Satellites
For my first shiny project, I was curious to explore this data set on the active satellites in orbit that I found on Kaggle. I wanted to learn about which countries use what satellites, what do we use satellites for, and where do we put the satellites in orbit? Here's what I found out.
Satellites by Country
Looking in the Map tab of the Shiny app, the first thing we notice is that the United States operates by far the most satellites. More than three times as many as China, the country that operates the second most. However, if we restrict to satellites run by military or government bodies launched within the last ten years, now China operates the most satellites, with USA second and Russia a close third. This is not so surprising given the different economic systems and rapid growth of the Chinese economy in recent years.
Purpose of Satellites
In the Purposes tab of the Shiny app, we see that more than half of all satellites are used for communications. If we restrict to the last 10 years though, we see that Earth Observation makes up significantly, and even overtakes communications as the primary purpose for non-commercial satellites. Digging deeper, I suspect that this is due to the fact that geosynchronous orbits are mostly used for communications, whereas low earth orbit is mostly used by earth observation, as we will see later. Geosynchronous orbits are more expensive to attain, so their satellites tend to have longer service lives.
Within the Orbits tab of the Shiny app, we see the big categories for orbit class are low earth orbit and geosynchronous orbit, with medium earth orbit and elliptical orbits being minor categories by comparison. As was said earlier, geosynchronous orbits are dominated by communications. This is not surprising since satellites in geosynchronous orbit always have line of sight with the same part of the earth. Earth observation is the top category in low earth orbit. Again not surprising since these satellites are mostly used for imaging and meteorology. The more interesting feature is that medium earth orbit is mostly occupied with satellites for navigation. Digging deeper, it turns out that these are mostly satellites for global positioning. Without diving too deep into how global positioning systems work, I do know that you need need line of sight to three or four satellites for the system to work. I suspect that despite being more expense to put the satellites in medium earth orbit, it is still more economical to do so since fewer satellites are required for the system to work at higher orbits.
Did you find something interesting within the Shiny app? If so, leave a comment about it below.