Two satellites positioned 559 miles above Pittsburg, Pennsylvania, are hurtling toward each other on a collision course. The odds are 1 in 100 that the two objects will impact.
A company called LeoLabs uses a worldwide network of ground-based, phased-array radars to provide high-resolution data on objects in LEO (low Earth orbit). Its LeoTrack mapping data and services are designed to limit the risks of collisions. Services target “the unique needs of today’s smallsat operators” and include “rapid orbit determination, early operational support, and ongoing orbit awareness.”
LeoTrack uses orbital information from the thousands of artificial satellites encircling the “nearby” outer space above the planet to figure out when the paths of trajectoried machines will cross each other.
That’s how the LEO-tracing company found out on Monday, January 28, 2020, that a decommissioned space telescope launched in 1983 and an experimental U.S. payload launched in 1967 would pass within about 30 yards of each other in two days, on Wednesday, January 30, at a relative speed over 9 miles per second.
As I wrote in October 2018, it’s time to take out the trash – in space:
“Space is big, but the space around Earth occupied by satellites is much smaller. Right now there are 4,857 satellites circling the globe. Some are live and transmitting data. Others are dead – true space junk.”
The United Nations Office for Outer Space Affairs (UNOOSA) has kept a list of all objects launched into outer space since 1962. This Register of Objects Launched into Outer Space became the UN’s way to identify which international States bear international responsibility – and liability – for space objects.
Today, more than 88 percent of all artificial satellites, probes, landers, crewed spacecraft, and space station flight elements launched into Earth orbit or beyond have been registered with the UN’s Secretary-General.
According to UNOOSA, a total of 8,378 objects have been launched into space as of January 2019. At that time, there were 4,987 satellites orbiting the planet, representing an increase of 2.68 percent compared to the end of April 2018. Another seven satellites have spun off into orbits around other celestial bodies.
Communication satellites come in all sizes. The biggest ones are comparable to a small school bus and weigh up to 6 tons, according to the Federal Communications Commission (FCC). Most comsats weigh a few tons or less but some tiny versions that are used briefly are 4-inch cubes that weigh about 2 pounds.
The Union of Concerned Scientists (UCS) records which satellites were operational as of the end of April 2018. Cross-referencing this data with that from UNOOSA shows that there are presently 1,980 active satellites in orbit high above our heads every day and night. Thus, 40 percent of all satellites in space are operational.
That means that 60 percent of all machinery in space is truly useless junk. Those 2,877 inactive metal meanderers all have decaying orbits since there are no thrusters to keep them at altitude.
In February 2009, nearly 500 miles above Siberia, two satellites (the inactive Russian satellite Cosmos 2251 and the active U.S.-based communication satellite Iridium 33) collided accidentally at about 22,300 mph. They exploded into a cloud of thousands of pieces of debris in what was the first known incident when two satellites collided in space.
Operators of satellites that travel below a certain height are supposed to put them in an orbit that will make them fall to Earth and burn up within 25 years. Those at high altitudes are boosted into higher orbits to get them out of harm’s way.
Most inoperable satellites (about 80 percent) burn up in Earth’s atmosphere after their orbits decay enough to encounter friction from air molecules. As of January 2018, between 200-400 tracked objects entered our planet’s atmosphere each year.
The remaining 20 percent of useless satellites plunge to the ground or land in the ocean. The only recorded victims of falling space debris are five sailors aboard a Japanese vessel who were injured in 1969 and an Oklahoma woman who was grazed by a piece of falling rocket in 1997.
Now, once again this week, there is a significant chance that two pieces of space junk will blow each other to smithereens high above the home of the Pittsburg Steelers.
LeoLabs agreed with this analyst that:
“Events like this highlight the need for responsible, timely deorbiting of satellites for space sustainability moving forward.”
The number of artificial orbiters is – dare we say? – sky-rocketing. SpaceX, founded by billionaire genius Elon Musk, launched 60 more Starlink satellites into low Earth orbit on January 6, 2020. The pioneering developer of the recyclable Falcon Heavy rocket now holds the record for the most satellites operated by a single company: 180.
The Starlink project purports to provide global high-speed broadband internet access. The FCC has authorized SpaceX to operate 12,000 Starlink satellites and may launch another 30,000 satellites in the future. The first 1,584 satellites will be deployed into 24 orbital planes of 66 satellites each.
A LEO satellite has an average lifespan of 5 years. The mission life of Starlink satellites falls between one and five years, at which time, “the satellite is designed to use its ion engine to deorbit itself and burn up in Earth’s atmosphere to avoid posing a space debris threat to other spacecraft.”
If it doesn’t crash into some other satellite beforehand, that is.