Introduction
Satellites are one of the fundamental assets in our global communication systems, and therefore important to our daily lives, economy, and environment. Some benefits they provide us with include long-distance phone communication, accurate weather conditions and forecasts, and international cooperation. The data that these space objects collect also assist in improving public safety and health. There are approximately 5,400 satellites orbiting the Earth, and I am interested in learning more about how they address the world’s societal needs, as well as the outer space landscape through the positions of these artificial objects.
Questions of Interest:
- What do the locations of the satellites depict about our worldwide communication and networks?
- Which areas surrounding the Earth are the satellites most present in?
- What kinds of insights can be made based on the type of orbit (altitude) each satellite is placed in?
Inspiration
I was inspired by this real-time, interactive map: https://satellitemap.space. There is a lot of information on it, but it was easy to navigate and select on the white dots that represented satellites. This map served as an initial guide to how I could approach my own visualizations.
This report should give readers an idea on how satellites shape the network of our global communications. Each visualization presents a different aspect of the satellite network.
Methodology
Tools
- UCS, ArcGIS, Google Sheets – for data collection and organization
- ArcGIS, Tableau – for data visualization
- Adobe CC – for visual refining
Dataset Preparation
The dataset, obtained from the UCS Satellite Database, includes information on at least a satellite’s orbit type, orbit height (km), launch date, and the organization/country it belongs to. Topics of interest to be found in this data include: which types of orbits are most populated, which countries and types of satellites dominate the network, and which areas the satellites are most and least covering in outer space.
Currently, the datasheet includes a list of the names of each satellite. In order to achieve what I wanted in the following three charts, I also needed to turn these satellite names into quantifiable units (see screenshot sample below). For example, I will need to calculate the sum of the number of satellites belonging to a certain country. After refining this dataset, 3 visualizations were created through Tableau, and a final, 3D Scene visualization created through ArcGIS.
Process and Results
PART 1: Introduction to the Orbits
Orbits (in this case) are the curved paths of satellites around the Earth. There are four main orbit classes that are focused on:
- Lower Earth Orbit (LEO): 160 – 2,000 km from the Earth
- Medium Earth Orbit (MEO): 2,000 – 35,768 km from the Earth
- Geostationary Orbit (GEO): 35,780 km from the Earth
- Highly Elliptical Orbit (HEO): less than 1,000 – over 35,768 km from the Earth
Manual calculations (i.e calculating the sum of the number of satellites in each orbit class) were done in Google Sheets and then imported into Tableau, where the following chart was created.
This simple chart provides foundational knowledge on the overall spaces that satellites are orbiting in, but doesn’t really show how far away they are in relation to the Earth. In the chart, most of the satellites are in the Lower Orbit (LEO), but the large size of the circle could be accidentally interpreted as the distance of the Orbit, instead of the number of satellites. So, I rearranged these circles through Adobe Illustrator to have them stacked on top of each other. Along with the added Earth icon, this visualization (see below) better showcases satellites’ distances in relation to the Earth.
PART 2: The Purposes of Satellites
These man-made objects also serve many different purposes, and often improve our lives in ways we don’t always realize. Some of the many examples include: broadcast entertainment, weather forecasting, navigation, and global phone signals. The following bar chart made via Tableau summarizes the number of satellites by their purposes.
It is clear from this bar chart that communication satellites are in the lead. This observation will be revisited later on in this report.
PART 3: The Countries with the Most Satellites
In order to gain an idea of the countries that are most involved with space technology, I created a 2D map on Tableau that showed how many satellites each country owned. In the original version of the visualization (see image below), the size and shade color of each of the dots corresponded to the number of satellites each country owned.
Style-wise, it looked nice. However, some of the detailed information became difficult to understand (i.e. clustered, small dots underneath larger dots were not clear). After some feedback from the class, I adjusted the color scale to show more contrast with the shades of red. Some of the countries on the map were also a little difficult to see, as a result of the overlapping between some dots. So instead of using dots, I decided to switch to filling in each of the country shapes with color. The following image is the updated version of the map:
After finishing this visualization, I learned that the USA’s 3,404 satellites was largely ahead of the rest of its competitors, with its nearest competitor (China) only having 532 satellites. The reason for this is mentioned in the Interpretation of Results section of this report.
PART 4: The Satellite Network
To showcase a summary of all the satellites orbiting the Earth, I created a 3D map scene through ArcGIS that displays the Top 10 Countries owning the most satellites. The dataset (by Celestrak and UCS) it derives from had many detailed descriptions that were not needed for this project, so I refined and filtered each pop-up interaction to display more concise and digestible information. Upon clicking on a line (which represents a satellite), you will see the Name of the satellite, the Country it belongs to, its Orbit Class, Launch Date, Launch Site, and its Purpose.
There were a variety of ways I could have used colors, and which pieces of satellite information I wanted to highlight. The basemap consisted of a monochromatic, dark background and globe in order to allow the satellite information to stand out instead of the Earth. The first version of the visualization I created had one layer representing all the satellites in the form of colored lines, and a second layer on the globe that showed how many total satellites each country had. At first, I was considering dots on the map, instead of lines so that they would be easier to look at. However, I then remembered that satellites are constantly moving (as shown in a map such as this), so static dots were not going to be accurate depictions.
After creating this original version of the map, I asked two additional people to interact with the map through Zoom sessions. In summary, participant comments mentioned that it was quite difficult to comprehend the 5,000+ satellites that were clustered into a single layer, and that the second layer was not visible enough unless the first layer was turned off.
After the UX research and trial/error, I ultimately decided to omit the second layer with the countries on the globe, and divided the first layer of satellites into 10 separate layers. Each layer represents a country. In each layer, the lines are further color coded based on the Orbit Class each satellite belongs to (LEO, MEO, GEO, etc.). As a result, the map was easier to navigate as there were now less lines to see at one time.
Result
The following screenshot is from the final result of the map. Click on the link under the image to access the full, interactive map. Toggle the layers (located on the right side of the map) On and Off to focus on the various countries and their presences in outer space.
Interpretation of Results
What activities are satellites most involved in?
The majority of satellites are evidently used for communications. This makes sense to me since such satellites are involved in many major aspects of technology we use today. A few examples are: in-flight communications on planes, television signals, Internet, and the primary timing source for phones and pagers. These satellites also help to transfer data from one point to another, such as money transfers (which is important for corporations, financial institutions, etc). In other words, these objects provide links between various points of the Earth.
Many satellites are also involved in Earth observations. These exist for things such as meteorology and environmental monitoring. Environmental information that these satellites collect include a multitude of things such as pollution, city lights, fires, ice mapping, and more. Since they also need to observe closely, I imagine that most Earth observation satellites are orbiting at relatively low altitudes (closer to Earth) compared to other types of satellites.
Why is the USA in the lead?
As shown clearly in Part 3’s map, the USA is in the lead with the number of satellites owned. This is largely due to the company SpaceX, which owns over 2,300 satellites as of September 2022. The company primarily aims to provide satellite Internet access to many countries, and global mobile phone services in the near future. These goals also correlate to the previously mentioned fact that most satellites are used for communication purposes.
The future of satellites
It is important to note that the data this project relies on is updated as of May 2022, so the number of operational satellites today is most likely not the same compared to half a year ago. According to the Statista Research Department, 95 satellites were launched in 2019, and estimates that the number of launches will exponentially increase between the years 2018-2030. The Satellite Industry Association also reported that nearly 1,200 satellites were launched in 2020, a significant difference in number compared to 2019.
Reflection
I feel that the data story I was trying to show was overall successful, specifically with my decision to organize my report in four parts and visualizations. I tried to start by sharing more simple, foundational knowledge about satellites (i.e. chart of orbit classes), and build up to showcasing more complex information (i.e. the 3D map).
Challenges
In the first part about the Orbit Classes, I had trouble creating what I had originally envisioned through Tableau. As a result, I had to use another program I was familiar with to adjust the graphic. Specifically, I was not sure if there was a method to stack the circles on Tableau.
Second, organizing the story of my topic, and the order in which I wanted to show each visualization ended up being somewhat challenging. The overall concept of satellites around the world was a relatively straightforward topic, however, there was a lot of data filtering and refinement involved, as the amount of information that exists about our satellite network is quite extensive. Much of my time during this project was spent on researching the data and facts, and learning the capabilities of the ArcGIS program. With the last 3D visualization, I would have liked to know of any alternate ways I can showcase the data. However, I’m satisfied with how much I’ve learned about Tableau and ArcGIS.
Future Steps
If I continue this project, I would like to experiment further with other aspects of the topic, such as unwanted satellites that have become space debris. The data that I worked with for this particular project covers satellites that are currently in operation, so I would need to find data on the ones not in service anymore, and conduct further research about concerns in using space sustainably. The overall data being gathered about all satellites would have to be updated too, since new satellites are always launching.
Resources
https://www.ucsusa.org/resources/satellite-database
https://rlist.io/l/dataset-of-all-satellites-launched-to-space
https://geoxc-apps.bd.esri.com/space/satellite-explorer/
https://www.ucsusa.org/resources/what-are-satellites-used
https://www.statista.com/statistics/896699/number-of-satellites-launched-by-year/