In the past couple of decades, humans have succeeded in penetrating the atmosphere and reaching their technological arm out in space. Today, with over six thousand satellites revolving around the earth, and thousands more sequenced to be launched, an enigma feared while the human inception into space is resurfacing, Space Junk.
But, how did space become the biggest junkyard? Why is space junk concerning? And what can be done to tackle the global issue?
What is Space Junk?
Ever since the beginning, the concerns about a potential outer-space junkyard created by space debris, satellites, bolts, and as little as chips of paint revolving around the globe at very high speed were on the plate. The issues related to space junk have been very well portrayed in movies like Gravity and WALL-E, as fictional it may seem, but with the recent spike in the satellites reaching the earth’s orbits, is already fretting government and concerned organizations globally.
But what exactly is space junk?
Unlike earth, when equipment expires or satellites’ lifetime is over they are not brought down or thrown in outer space. Instead, since already in a free-fall, they keep on revolving in their defined trajectory forever. For example, according to Geo Spatial World, as of January 2021, there are nearly 6,542 satellites orbiting the earth, of which only 3,372 are functioning, while the rest are inactive. But, they are still in their fixated orbit, revolving around the earth.
Moreover, anything from spent rockets to stray bolts to the tiniest flecks of paint, all form the space junk. In a nutshell, space junk is any material or machinery left by humans in the inner and outer space. A majority of this junk is orbiting in the earth’s lower orbit, the closest and most used part of the earth. This lower orbit homes thousands of active and inactive satellites, including the international space station.
All of this is moving at speeds as high as 27,000 kilometers per hour. At this high speed, when even a baseball-sized piece hits something, it packs a punch. According to a report, today there are over 34,000 large pieces of debris, 3,000 dead satellites, and millions of smaller junk revolving over our heads.
The Accelerating Concern
While, currently, space junk is not a big problem, Blue Origin and SpaceX planning to launch an estimate of 50,000 satellites into orbit, the area around the earth could get a lot more congested, fueling bigger issues for future space missions.
But, modern life and technology depend on slate tiles, everything from GPS to the internet is all facilitated by them. Moreover, the advancements are making the launch of satellites easier and more feasible.
The sheer scale of debris in space has formed orbits just for inactive satellites, the graveyard orbits. No organization or government can be held solely responsible for the problem, every nation has played its role in filling the space with junk, exponentially increasing the collision risk. But, the collisions only contribute to 0.8% of all the space debris, the major contributor is blasts caused by leftover batteries, fuel, spacecraft, rockets, and energy.
Including the International Space Station, Collision Avoidance Maneuvers are performed by numerous satellites every year. In the past, the ISS has to change its trajectory over 30 times to avoid collisions.
Dr. Donald Kessler, NASA scientist, in the year 1970s, proposed the Kessler syndrome, a tipping point for the space junk. As more collisions and blasts of satellites take place, more junk is added to the orbit, creating an infinite cycle of space debris. This exponentially growing ring of junk around the globe can confine us to the earth.
Space Junk: What is the Solution?
A considerable amount of debris will burn up in Earth’s atmosphere after losing altitude over time. There is already so much space junk in Earth’s orbit that it is likely to continue multiplying for centuries to come as orbiting pieces collide.
According to computer simulations, debris larger than 8 inches across will more than double in size during the next 200 years. Smaller particles, however, will double even faster. A pile of debris between four and eight inches is expected to multiply 3.2 times, while that beneath four inches will increase by 13 to 20 times.
Over the years, the constellation of satellites we see above has become increasingly important. In addition to being useful for science, they are also essential for communication, navigation, weather forecasting, etc. Therefore, rather than halting future launches, scientists are looking into a variety of methods to reduce and remove space junk.
There are a number of concepts in development to control space junk that resembles science fiction more than reality. Japanese space agency JAXA is testing what is known as the electrodynamic tether (EDT), a six-foot-long electronic space whip. Almost 2,300 feet of electrified line are capped by a 44-pound weight. The device is designed to knock debris out of orbit, causing it to burn up in Earth’s atmosphere.
That is by no means the only option. In addition to giant magnets, harpoons, and nets, whittle-down the debris cloud safely is proposed with giant magnets, harpoons, and nets. The problem is being fought from both sides of the equation. Many nations are taking steps to ensure that future orbiters launched above Earth’s surface will have a safe end-of-life plan to limit the growing debris cloud enveloping the planet.