Humans have managed to put a whole bunch of stuff in orbit around the Earth, and keeping track of it all is a serious endeavor. Visualizing the sheer number of objects we’ve managed to send into space also helps us appreciate just how vast space really is. These amazing maps illustrate the cloud of man-made objects encircling our blue marble.
Flight Club spoke to Richie Carmichael, a software developer and geographic information system (GIS) expert at the Environmental Systems Research Institute, also known as ESRI, who created the incredibly cool mapping tool that tracks all of these satellites. If you want to see Carmichael’s site with the full mapping tool, click here, but the story behind it is pretty fascinating in its own right.
Carmichael created the tool using a Javascript library that supports both 2D and 3D maps. His maps depict three distinct bands of satellites, each of which have different characteristics.
Low Earth Orbit (LEO)
As the name suggests, these spacecraft maintain the lowest orbits, between 99 miles and 1,200 miles above the planet, and circle the Earth most frequently of any orbiting satellite. Low Earth Orbit is the domain of the International Space Station and all other manned spaceflight throughout history, with the exception of the the Apollo missions. Low Earth Orbit is also where most space junk is located.
Medium Earth Orbit (MEO)
This “mid-range” mostly consists of telecommunication and navigation (GPS, GLONASS, Galileo) satellites, orbiting between 1,243 miles and 22,236 miles above the planet. The GPS constellation, which is operated by the U.S. Air Force as a free service for Earth’s citizens, consists of 27 spacecraft in Medium Earth Orbit.
Geosynchronous and Geostationary Orbits
Satellites in Geosynchronous (orbiting at the same rate that the Earth rotates, keeping station over a single line of longitude) and Geostationary (remaining in a fixed position as observed from the Earth’s surface) orbits comprise the outer band, about 22,236 miles above the Earth. According to Carmichael, “this is a perfect position for television relay satellites.” One of the companies occupying this incredibly competitive space is Inmarsat, whose satellites supply communication to aircraft and is one of the many companies enabling in-flight WiFi. Companies like SiriusXM and DirecTV also park their satellites in geosynchronous orbits. Because of their relatively high altitudes, only a few satellites are needed to cover the majority of the planet.
Beyond just exploring the different orbits that satellites occupy, Carmichael’s maps are useful and important for a host of different organizations. For example, if a natural disaster were to occur, many parties would want to know when the next flyover opportunity from an imaging satellite would take place.
Carmichael’s maps are even able to illustrate which satellites belong to which nation. The map above shows spacecraft of Russian origin, highlighted in red. Per Carmichael’s site, there are 5,289 Russian-made satellites in orbit, or roughly 38 percent of the total number of objects.
While Carmichael’s mapping tool can show which objects are space junk, it doesn’t show how collisions between objects might cascade into one another, sending our delicate satellite balance spiraling out of control. This terrifying scenario, known as Kessler syndrome, could create an uncontrollable swarm of debris in space that ultimately prevents any objects from escaping the clutches of Earth’s gravity without incurring significant damage.
This exact scenario was depicted in the 2013 film Gravity, in which Russia destroys a defunct satellite with a missile. The ensuing explosion sends thousands of pieces of debris zooming in all directions, causing destructive impacts with nearby objects in space. These impacts cause further impacts, eventually leading to an inescapable chain reaction that threatens a fictional American Space Shuttle orbiter called Explorer. While Gravity took some liberties with orbital physics, it is important to note that China intercepted one of their own weather satellites in 2007 with a missile, and Russia and the United States have anti-satellite missiles of their own. The 2007 Chinese explosion created a cloud of debris (with an estimated 150,000 particles) that will continue to threaten spacecraft and space activity in perpetuity, or, at least until all the debris finally comes tumbling down.
As the humankind prepares to launch forth into the deep of space on manned missions to asteroids, Mars and beyond, it is important to see what we’ve accomplished since our species first took aim at the stars. Let’s just hope we can get there before we’ve made Earth’s perimeter too crowded to escape.
Special thanks to Richie Carmichael and Amanda Marzullo with ESRI for their assistance with this post!
Photo credit: Richie Carmichael/ESRI
Follow the author on Twitter: @collinkrum