Imagine if a person obliterates half of the living creatures across the Universe to prevent overpopulation and restore balance. He might feel that the deed would provide hope for the other half. What if the other half laments the loss and fails to thrive, contrary to what the person believes? This scenario is where the effect becomes the cause.
The space sector has improved dramatically across the world. We are launching countless rockets and placing many satellites in orbit. To observe the Universe, we use space telescopes.
Hurrah! Finally, improved space technology has provided us with luxury of losing ourselves in the glory of the Universe, while sitting cozily at home. The entire Solar system will be at our reach in a few years.
Really? Is that true?
When we launch a space vehicle, its stages detach at some point. While some of them return home, the others stay in the low Earth orbit revolving at high speeds. This problem might have been simple if we had not conducted missile, anti-satellite and nuclear tests in Earth's vicinity.
Countries like US (Operation Burnt Frost), Russia (PL-19 Ludol), China and India (Mission Shakti) have successfully tested their anti-satellite weapons. But still, some of the debris generated can pose risk for orbiting satellites for many years to come. Importantly, the missile must strike the defunct satellite head on to prevent most of the debris from reaching the orbit.
These tests, combined with a lot of spent rocket boosters, dead satellites, and millions of metal shrapnel, have formed a metallic graveyard around our planet that travels at destructive speeds. In other words, Humanity has led to space pollution.
Dangers of Space Debris
We have some of the most critical components in the Earth's orbits that are responsible for modern technology like communication, internet, GPS, and broadcasts. What would happen if a minute metal piece traveling at enormous speeds strikes one of these components?
Even shrapnel traveling at such speeds resemble bullets. They can punch holes in the working satellites and destroy them. Imagine the damage that big floating chunks of booster stages can do!
We are steadily transfiguring the Earth to look like Saturn with randomly oriented human-made rings in a few decades if we launch space vehicles at the current rate. We might even end up having a Dyson megastructure for ourselves.
Chain Reaction
The most fearsome part of the concept of space debris is Kessler syndrome. According to this, the collision of space debris can produce more junk with a variety of sizes, which will induce more accidents. In other words, this entire phenomenon will become a chain reaction or an exponential collision cascade. We can also refer to it as a Domino effect of space debris.
We cannot debunk the seriousness of this situation by bringing in the vastness of space.
The sounds that I heard were either the metallic pops due to compression-expansion effects or the occasional bullet-like bangs due to the debris striking the thin aluminum hull.
- A former ISS astronaut Chris Hadfield
By the above statement, you must realize that debris crashes are not as rare as it seems.
A large scale collision already happened between the United States' Iridium 33 and Russia's Kosmos 2251 in 2009 over northern Siberia. It resulted in a cloud of thousands of minute metal particles.
The ISS's Measures Against Space Debris
In 2016, even the International Space Station reported a 7 mm crack in a window of the Copula module caused by a junk chip.
Thankfully, the ISS's windows are much thicker than a typical household window and consist of fused silica and borosilicate. Also, extensive shielding around crew modules can defend the astronauts from damage.
An object up to 1 cm in size could disable an instrument or a critical flight system on a satellite. Anything above 1 cm could penetrate the shields of the Station's crew modules, and anything larger than 10 cm could shatter a satellite or spacecraft into pieces.
- European Space Agency
The ISS has significant countermeasures, though. It uses the mechanism of a Whipple shield for small shrapnel debris. Such protection consists of several plates placed at some intervals. Small, fast pieces break apart and vaporize instantly on impact with the outermost shield due to the enormous energy involved. As a result, they only leave a dust mark in the subsequent thin wall. ESA successfully conducted a test with a Kevlar Whipple shield with an inner Aluminum wall.
Even the ISS isn't safe with larger debris. There is no other option than readjusting the maneuver if a big junk appears within a particular distance from it.
Fermi Telescope - Kosmos Collision Course
In the year 2012, the Fermi Gamma-ray telescope was to cross the retired Russian Kosmos 1805 with a separation of only 700 feet. Fermi telescope had to change its maneuver and undergo a one-second burn from its thruster to dodge the 1.5-ton bullet. It was a matter of anxiety as these thrusters didn't follow any tests, and their only job was to push Fermi away from Earth's orbit at the end of its life. But everything went well, and Fermi is a crown jewel of space telescopes even today.
Gravity
Debris is the worst thing that you want to encounter while attempting a spacewalk. If you want an example, you can watch the breathtaking first scene of the movie Gravity. When the NASA astronauts try to service the Hubble Space Telescope, a cloud of debris triggered by a Russian anti-satellite test intercepts them. It damages their shuttle (Explorer) and the Hubble Space Telescope. With the space debris as the antagonist, a terrible nightmare unfolds as we witness Dr. Ryan Stone's desperate effort to survive, amidst the darkness of space.
Eliminating Space Debris
Removal of space debris from lower Earth orbit is one of the hottest topics of discussion today. Experts have suggested many ways. Some of them include satellites with a giant net or a harpoon to catch and push large metallic chunks into the atmosphere.
One of the wildest and most promising theories includes aligning a giant electromagnet in the Earth's orbit to repel the space junk away. This electromagnet would be such that it remains stable by utilizing the Earth's magnetic field. This idea shows promise because it doesn't interact physically with the debris and hence, can avoid accidents. If something wrong happens with Harpoon or net, it might damage the junk-removing satellites, thus contributing to more space debris.
The British RemoveDebris project successfully demonstrated the usage of nets and harpoons to capture space debris.
There have been suggestions to use lasers to vaporize minute shrapnel. Of course, reusable rockets are the saviors today that can avoid adding the lower rocket stages to the Earth's orbit.
Earth - A Future Mega-Prison
Decades ago, we were not able to reach outer space. It was the cause that drove us towards making space vehicles. But by just conducting launches and missile tests and not removing the resultant debris, we are shooting ourselves in the feet. We are building our prison to lock ourselves away from space exploration. If the same continues, many useful satellites will have a premature end. We will have a massive setback in terms of technology and the difficulty to cross low earth orbit will rise alarmingly.
Remember that space debris and working satellites have a profoundly ingrained prophecy connecting them.
Neither can live while the other survives.
We have to eliminate one of them (preferably the debris) to avoid accidents.
While attempting to reach space, we are preventing the same. We are slowly converting the effect into the cause itself—our dream of setting up colonies on Mars, moon, or Titan will meet its end before we even begin, if we don't act soon.
Sources
Thanks to HUFFPOST, YouTube (mainly the channels Kurzgesagt - In a Nutshell and Learn Engineering), Wikipedia and BBC.
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