Space Debris: A Growing Threat?

How NASA Plans to Clean Up Our Sky

This June will mark the 80th anniversary of humanity first launching objects into space. Since then, there have been countless achievements, from satellites to space stations, moon landings, and solar probes. It would seem there are few limits to what we can achieve.

Amongst our travels, however, one consequence risks destroying much progress in space expeditions: space debris. Space debris is any object, large or small, abandoned in space by humans. It can range from decrepit spacecraft, screws, or even chips of paint.

Credit: Unsplash.

Like other challenges facing humanity, this problem is one of our own making. Decades of launching rockets without considering the long-term impacts, alongside numerous tests of anti-satellite weaponry, have left Earth’s orbit littered with debris. NASA estimates an upwards of 500,000 “marble-sized” objects and over a 100 million objects smaller than 1mm in space. Whilst all of these objects pose a serious threat, the smaller ones may be more potent. According to NASA’s assessment, smaller objects are nearly impossible to track, and thus difficult to evade should the need arise. 

The Kessler syndrome, a theoretical proposal by a NASA scientist in 1978, describes a worst-case scenario for the damage that space debris can cause. According to Donald J. Kessler, crisis occurs when object density within a low Earth orbit is high enough that should an object impact a satellite or some other structure, the debris generated by that impact would go on to create more collisions, and so on, until that entire region would be filled with deadly hazards. In simpler terms, the Kessler syndrome is a domino effect. Its ramifications would be devastating, possibly even locking off an entire region for satellites or preventing spacecraft from safely traversing the area. 

Thankfully, such a situation has not occurred. This is partially attributed to the dedication of NASA and its partners in pursuing solutions. In the 1990s, NASA was the first agency to output materials which mitigate damage from encounters with space debris. Since then, NASA has continued working with international partners to develop countermeasures and methods to minimise the creation of new debris. In 2007, such work culminated when the United Nations adopted international guidelines for mitigating space debris. 

Despite this positive progress, there have also been some setbacks: anti-satellite tests, which generate substantial debris fields, continue to be conducted. One test undertaken by Russia in 2021 even threatened the International Space Station, resulting in the station taking evasive manoeuvres. Fortunately, the station was not damaged, but such close calls could become the norm even with NASA’s mitigation strategies in place. 

According to the organisation's estimates, even without new launches, the amount of material already present in space would, with enough collisions, over time produce the Kessler Syndrome. This means actions must be taken to rapidly reduce the amount of redundant or retired hardware in space. This has caused NASA to move beyond just mitigation by ensuring that anything launched into space must be accounted for by its owner for the entirety of its lifetime and adequately disposed of at the end of its service. NASA has already fined Dish Network, an American satellite television company, for creating space debris by failing to de-orbit its satellite. In the future, other would-be violators may do their due diligence to avoid such repercussions. The issue of space debris can easily make one fearful for humanity’s future exploration beyond Earth, and to soothe your mind, remember this: dozens of teams worldwide are working around the clock to find methods to quickly and cheaply remove debris from orbit, preserving our gateway to the stars. This dedicated work by NASA and its international partners in managing space debris should give hope that this issue will soon be relegated to history books.