Space debris is a growing concern for the space industry and the safety of our planet. As we continue to rely more on satellites for communication, navigation, and scientific research, the accumulation of debris in Earth’s orbit poses a serious threat to our space infrastructure. It’s estimated that there are over 100 million pieces of debris larger than 1 mm in diameter orbiting Earth right now. Imagine the impact of a collision with even a small piece of debris.
Here we will discuss everything about space debris that you need to know. Let’s start now.
What is Orbital debris?
The term “orbital debris” pertains to any object that was made by humans and is currently orbiting around the Earth, but no longer has any practical function. This encompasses spacecraft that have been abandoned, upper stages of rockets, and vehicles that are designed to carry multiple payloads. During spacecraft separation from its launch vehicle or mission operations, the team intentionally releases other types of debris. Spacecraft or upper-stage explosions or collisions, solid rocket motor effluents, and tiny flecks of paint released by thermal stress or small particle impacts create debris.
As Alice Gorman writes in her book “Dr. Space Junk vs The Universe: Archaeology and the Future, “There are places where litter is acceptable and others where it is not. What is the proper place for space junk? You could say it is the atmosphere: that abandoned satellites and debris should be cremated, ashes to ashes, dust to dust. There’s a contradiction here. We’ve placed junk where it is perpetually ‘out of place’ as a human object, but in another sense, this is its natural place.”
The impact of orbital debris on space exploration and the safety of our planet cannot be underestimated. Currently, more than 25,000 objects larger than 10 cm are known to exist. Additionally, there’s an estimated population of particles between 1 and 10 cm in diameter, which is approximately 500,000. Shockingly, the number of particles larger than 1 mm exceeds 100 million. Furthermore, as of January 2022, the amount of material orbiting the Earth exceeded 9,000 metric tons. In recent years, the issue of orbital debris has become a growing concern in the space industry.
Now Let’s discuss the
Determination of Space Debris:
Most of the orbital debris resides within 2,000 km of the Earth’s surface, and the amount of debris varies significantly with altitude. The greatest concentration of debris can be found near the altitude range of 750-1000 km. This concentration poses a significant threat to space infrastructure in that altitude range.
The U.S. Space Surveillance Network routinely tracks large orbital debris larger than 10 cm. Ground-based radars can detect objects as small as 3 mm, which provides a basis for a statistical estimate of their numbers. The U.S. Space Surveillance Network has been critical in monitoring and identifying potential collisions between space objects and debris.
Assessments of the population of orbital debris smaller than 1 mm can be challenging, but they are essential to understanding the scope of the debris problem. Scientists have limited the examination of impact features on the surfaces of returned spacecraft to those operating in altitudes below 600 km. Detecting and tracking small debris requires new methods to provide a more comprehensive understanding of the debris problem, which is an ongoing challenge.
NASA reports that in 2009, a decommissioned Russian spacecraft collided with a functioning U.S. Iridium commercial spacecraft, resulting in the destruction of both and contributing over 2,300 pieces of space debris to orbit. Recently, in March 2021, a fragment from a Russian rocket destroyed a working Chinese military satellite. In June of the same year, an unidentified piece of space debris struck the robotic arm of the International Space Station, causing damage but not destruction. As the amount of space debris increases each year, such incidents are becoming more frequent.
You would also be concerned about,
What is the Impact of Space Debris on Space Infrastructure?
A significant amount of debris does not survive the severe heating that occurs during reentry. The components that manage to survive reentry are highly likely to end up in bodies of water such as oceans or sparsely populated regions like the Canadian Tundra, Australian Outback, or Siberia in the Russian Federation. Scientists have recorded an average of one piece of debris falling back to Earth per day over the last 50 years. There have been no confirmed instances of reentering debris causing any serious injuries or significant property damage.
Orbital debris circles the Earth at a speed of about 7 to 8 km/s in the low Earth orbit, below 2,000 km, and it can be found in significant amounts. The typical velocity at which orbital debris collides with another object in space is roughly 10 km/s, and in some cases, it can even exceed 15 km/s. This is over ten times faster than the speed of a bullet. As a result, collisions with even a small piece of debris can lead to catastrophic consequences.
Companies deploying low-altitude commercial communication satellite systems such as Iridium, Orbcomm, and Globalstar are designing ways to minimize orbital debris generation. These systems do not pose unique debris problems. Often, upper stages and spacecraft are placed in lower-altitude orbits. This is done to accelerate their fall back to Earth after completing their missions.
However, there are some,
The Long-Term Effects of Space Debris:
The higher the altitude of debris, the longer it remains in Earth’s orbit. Debris left in orbits below 600 km typically falls back to Earth within several years. Orbital decay at altitudes of 800 km can take centuries to occur. Above 1,000 km, orbital debris will normally continue circling the Earth for a thousand years or more. Debris accumulation over time is a serious concern. It could result in a cascade of collisions, which could lead to an increase in debris. This increase in debris has the potential to cause long-term damage to space infrastructure. Thus, cleaning up orbital debris and preventing its creation are essential for space exploration.
Now if you are wondering,
What are the precautions we made so far?
Leading space agencies worldwide have made efforts to address the issue of orbital debris. They formed the Inter-Agency Space Debris Coordination Committee (IADC). As well as the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS). These committees have published guidelines for international compliance
While some debris will naturally fall back to Earth and burn up, the amount of space junk in low Earth orbit will continue to grow due to collisions between existing debris. As our reliance on satellites for communication, navigation, and other purposes increases, researchers have been exploring various methods to remove and reduce the debris cloud, including technologies such as electronic space whips, giant magnets, harpoons, and nets. Additionally, many nations are limiting future debris by ensuring new spacecraft have appropriate end-of-life plans.
- Russia, China, Japan, France, and the European Space Agency: These countries have all issued orbital debris mitigation guidelines.
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United States:
Since 1988, the official policy of the U.S. has been to minimize the creation of new orbital debris through orbital debris mitigation. In 2010, the National Space Policy was established to preserve the space environment, including orbital debris mitigation. The directive instructs NASA and the Department of Defense to research and develop technologies. The aim is to lessen and eliminate debris in orbit.
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Space Policy Directive-3 (SPD-3):
The SPD-3 issued in June 2018, highlights the threat of orbital debris and emphasizes the need for periodic revisions of debris mitigation guidelines, standards, and policies. It further calls for the development of new protocols of standard practices. These protocols aim to promote efficient and effective space safety practices in the U.S. industry and internationally.
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The International Space Station:
ISS’s primary focus is to prevent the unnecessary creation of additional orbital debris by implementing cautious vehicle design and operations. The U.S. Space Surveillance Network regularly monitors trajectories of orbital debris to identify any potential threats to the ISS. The ISS typically maneuvers away from any object if the risk of a collision exceeds 1 in 10,000, which happens approximately once a year on average.
The ISS shields itself highly, making it the most robust spacecraft ever flown, and its habitable compartments and high-pressure tanks can typically withstand debris impacts as large as 1 cm in diameter. Although the risk of debris ranging from 1 to 10 cm in diameter striking critical ISS components is low, researchers are working to investigate ways to reduce this risk even further. The task of removing debris from space is still a substantial hurdle from both a technical and financial perspective.
So, let’s conclude this by saying,
Crux of the discussion:
You don’t have to worry too much about space debris colliding with the Earth’s surface. Space agencies worldwide are taking steps to mitigate the creation of new debris. They are also working to remove existing debris from Earth’s orbit. It’s no wonder, given the potential risks associated with orbital debris. As long as we know to overcome the effects of Space junk, we are completely safe!
