In one of his recent articles, Max Polyakov, a managing partner of Noosphere Ventures, spoke about the space junk issue and listed potential solutions. He believes that satellites developed by modern aerospace companies can offer a proactive garbage reduction.
We must do several things to clear debris, and we must coordinate and collaborate to prevent further accumulation. We must work together to prevent space pollution from increasing.
On the other hand, Earth faces a lot of challenges, so why do we fund space exploration? Mostly because space instruments would enable the solution of Earth-based problems. For example, a constellation of satellites will soon ensure Internet access all over the world.
Despite the tremendous benefits provided by our orbiting spacecraft, we must ensure that space pollution doesn’t increase and build up enough to impede our next space destination.
How Much Orbital Debris Is There?
More than 2,200 active satellites are already orbiting Earth. Due to the space industry’s progress, space junk continues to increase. The latter includes defunct spacecraft and rocket parts that are no longer usable.
Starting with Sputnik I launched in 1957, space junk piles up. In 2020, about 900,000 tiny bits of trash, ranging from 1 to 10 cm in scale, were circling Earth. Add an even larger number of smaller pieces, and one gets a total debris density of 7 million kilos. With time, a satellite will deviate from its orbit, re-enter the atmosphere, and burn down in it. However, it isn’t enough.
Low Earth orbit (LEO) and geostationary orbit (GEO) are the primary places where satellites and space debris are located.
Thousands of satellites reside in Earth’s equatorial plane defined as geostationary orbit, just 30,000 km above the planet’s surface. Meanwhile, the satellites that are already out of order turn into space junk.
A geostationary orbit is still inhabited by a lower amount of debris relative to the upper atmosphere reaching up to 2,000 km above Earth’s surface. To enter higher orbits, a spacecraft must first fly through the low-Earth orbit (the densest region of space with most of the debris). Often, space debris in LEO causes a danger to spacecraft.
As long as people launch objects into orbits, there will always be garbage. Debris that includes fairings, cameras, and other fragments remain in space after rocket launches. Among all debris-producing events, rocket explosions are the top cause. Orbital garbage generated by human operations includes the likes of pliers, sensor kits, tool bags, and gloves used by astronauts. There are micrometeoroids too, in other words, particles of asteroids and comets.
Satellites with short lifetimes can become space waste very fast after their cycle runs down. Next, batteries wear out, and solar panels degrade, which results in a debris feedback loop. Any satellites that reach orbit begin to break when they re-enter the atmosphere. The higher the orbit, the more time the deterioration process will take. Still, it is inevitable.
Over the last six decades, the number of space debris fragments in Earth orbit has greatly increased. More garbage is generated due to space activities, and the possibility of negative outcomes is much higher. “Kessler syndrome” is a name for a theory proposed by NASA researcher Donald J. Kessler that says the accumulation of space debris will make LEO inaccessible for decades. The 2013 movie Gravity shows astronauts after debris strikes their space shuttle; it serves as a cautionary tale of mankind’s careless destruction of Earth.
Debris of any size presents a threat. They can destroy optics and solar panels, making it more difficult to repair the equipment and raising the likelihood of unserviceable equipment. The amount of energy a 1kg object moving at 7 km/s releases equals the amount of energy used to detonate 6 kilograms of TNT.
In the future, traffic in LEO would greatly increase. SpaceX, Amazon’s Project Kuiper, OneWeb, and Telesat suggest placing 50,000 satellites in low Earth orbit, but some believe the actual number could exceed 100,000 satellites. Even now, the likelihood of satellite and orbital debris incidents is high. To avoid a possible crash, NASA launched the Progress resupply module in September 2020. It was attached to the ISS to increase its altitude and avoid collision with space debris.
What Can We Do About Space Junk?
NASA issued the first proposals in the mid-1990s. They were designed to help alleviate the growing orbital debris problem. Other nations quickly began to catch up. In 2002, an agreement was established among ten member countries that comprise the Inter-Agency Space Debris Coordinating Committee on space debris management recommendations.
Right now, aerospace companies are building small satellites that can pick up space junk. Different thrusters are used depending on the satellite’s task. One uses ion, Hall Effect, and plasma thrusters to reduce the amount of debris generated by rockets. Eventually, these spacecraft have to be sent into Earth’s atmosphere using only ion and plasma thrusters. In Japan, researchers are designing experimental wooden spacecraft to see if it is possible to prevent debris when spacecraft are deorbited and start entering Earth’s upper atmosphere.
To prevent space junk from accumulating, space companies aim to use spacecraft to capture the debris. The emergence of debris-attracting systems, including nets, harpoons, and magnets, is progressing. A Japanese research team is developing a de-orbiting technique that uses a particle beam to deorbit a satellite. This stops the satellite in orbit, lowers its orbit, and causes its falling to Earth.
When countries launch satellites on their own vehicles or on other countries’ rockets, the permission to function in orbit might need a fee approach. Then it’s feasible. While each country is permitted to charge a fee based on the risks in orbit, the fee should be based on the collision danger for each launched satellite.
Several countries have implemented similar approaches in terms of carbon taxes or fisheries conservation. The value of the satellite industry under a business-as-usual scenario is projected to rise from about $600 billion to $3 trillion by 2040. Increasing the odds of a safe and successful satellite launch can eventually make launching more affordable and conscious.
More effective steps can be taken as different industries work together to stop the buildup of possible space debris and prevent the accumulation of space junk.
Debris in space poses a danger, but removing it should bring space companies together. Collaboration makes solving the problem easier. In other words, as Dr. Polyakov states, the disposal of debris presents enormous opportunities for entrepreneurial creatives who want to save the orbit and our planet.