There is so much space debris that we have lost control of many objects: how serious is the problem

The space race adds a new historical date, one of those that should be managed and, in its own way, mark a milestone: March 4, 2021. We do not set foot on any inhospitable planet, nor do we launch a new study instrument, such as the James Webb . The feat on this occasion was much less epic and much more embarrassing. For the first time since we have dedicated ourselves to exploring the universe, an out-of-control piece of garbage “made in Earth” of dubious origin hit the surface of the Moon. It did so without us sending it there or having any idea whether SpaceX, China, or some other corporation or country is responsible.

As far as is known, the impact—the fragment is believed to be the booster for the Chang’e 5-T1 spacecraft—does not endanger any spacecraft or mission. In itself, it is not a tragedy. If it is alarming, it is because of its meaning: it shows us that space debris is a very real problem.

Neither new nor minor. That’s right, space debris is not a new or minor problem. Since the space age began in the 1950s, we have launched thousands of rockets and as many satellites into orbit. It is not easy to keep track. On February 3 alone, SpaceX launched 49 into low Earth orbit for its Starlink service, most of which were rendered useless shortly after by a geomagnetic storm.

We do, however, have some data that help us size up the problem. A report published two months ago by NASA shows that low Earth orbit (LEO) hosts at least 26,000 fragments equal to or larger than a baseball, large enough to destroy a satellite. Of the dimensions of a marble there would be more than 500,000 and more than 100 million similar to a grain of salt. It may seem like a minuscule size, but if one of them were to hit an astronaut’s suit it could puncture it and put it in serious trouble.

A graveyard of hardware above our heads. Data from the European Space Agency (ESA) help complete the picture. According to his estimates, there would be around 7,800 satellites in space, many of them inactive, and 36,500 pieces of space debris that exceed 10 centimeters. Of course, the four-tonne projectile of March 4 is not the first to leave its mark on the Moon. Over the past two decades, at least LCROSS, LADEE, or Smart-1 have crashed into the surface of the satellite. None of these cases can be compared to the one from a few weeks ago, a remnant that we did not send to the Moon and with no clear origin.

Controlled… but to a certain extent. Are those wastes monitored? Yes. Although not homogeneously. Much of the attention is focused on the field of LEO, low Earth orbits, located at an altitude that usually does not exceed a thousand kilometers and are used, for example, for the ISS or satellite images. After decades of launches, NASA recognizes that the LEO region is today “a junkyard”, with millions of ship parts, paint chips, rocket parts and satellites… It is estimated that in low Earth orbit there are some 6,000 tons of garbage. For example, LeoLabs, with offices in Menlo Park (California), or the Center for Space Domain Awareness, known as CSDA, are in charge of keeping an eye on its drift.

how to pick up Nature, the US Space Force is responsible for tracking objects to geostationary orbits, about 35,800 kilometers from Earth. The question is: What happens to the farthest garbage, closest to the Moon, located almost 400,000 km? The monitoring in these cases is in the hands of groups of researchers such as Vishnu Reddy, from the University of Arizona, which regularly tracks the position of more than a hundred and a half objects located around the Moon, the vast majority space junk. Astronomer Bill Gray, who discovered the debris that has ended up colliding with our satellite, points out in fact that there is no organization that is in charge of tracking the most distant objects in space.

A system that can (and should) be polished. What just happened with the booster that hit the far side of the Moon is the best example that the system can improve. At first, years ago, Gray’s team concluded that it was a SpaceX rocket and later pointed to China’s Chang’e 5-T1 mission. The reality is that there are still doubts about the origin of the space debris that has left a new dent in our natural satellite.

It is not the only weak point of the system. Professor Don Pollacco, from the University of Warwick, recently explained to Science Focus that even in the closest region, the effectiveness of control is reduced when we talk about small pieces. “Once you start to get below spacecraft size, then we don’t monitor things well enough to continually know what’s out there. The number of small things, even four inches in size, is not really known except through models.”

And what happens to all that garbage? Although a good number of fragments end up burning when they fall into the atmosphere, the truth is that the garbage is already causing headaches for those responsible for space missions. Since 1999, the International Space Station (ISS) has had to carry out more than twenty maneuvers to avoid debris. In November, it was forced to do a similar operation to avoid remnants of a Chinese satellite. Around the same time, the station also saw how a Russian operation put it in danger.

Garbage and/or business? “In all the satellites, hundreds of maneuvers are carried out each year to avoid collisions,” the MNH abounds. In recent times, both public bodies and the private sector, which has seen a good business opportunity, have been in charge of activating initiatives to try to alleviate the garbage that flies over us. There are control and monitoring programs, such as the US Space Surveillance Network, and missions that want to eliminate at least part of the waste, in the style of Clear-Space-1. In this effort, NASA or ESA are joined, among other companies, by Privateer, Astrocale, Airbus, ExoAnalytic or even SpaceX. Where most of us see garbage, a business is also opening that promises to mobilize large resources.

An “unsustainable” situation. “Imagine driving down a road where there are more cars, bicycles and vans broken down than vehicles in operation. This is the scene facing our satellites in Earth orbit,” explains the ESA with a metaphor that clearly reflects what it means And what can space debris mean? And ditch: “Our current behavior in space is unsustainable. If we continue as we are, the number of objects in orbit will make safe operation in space difficult. The number of objects in space, including their combined mass and their combined area, is constantly increasing.”

Although the ESA recalls that most of the debris from rockets and high-altitude missions ends up being disposed of without any problem, it emits some red lights: it warns that the behaviors in the lowest orbit “are not changing fast enough” and that, finally, On average, each year there are 12.5 unplanned events that generate debris. The truth is that just a handful of crashes can lead to a big problem. NASA estimates that the destruction of the Fengyun-1C spacecraft in 2007 and the accidental collision of an American and a Russian spacecraft in 2009 increased orbital debris in LEO by about 70%.

And that extends to greater distances. Nor does it come that control efforts are limited to the lowest orbits. Alberto Águeda, from the GMV company, explained a few days ago to The country that so far what was recorded beyond the Moon “has not been perceived as a problem”. The scenario could change from now on with the increase in missions that target our natural satellite. This year alone they plan to arrive there half a dozen ships.

At closer heights we face the challenge of increasing satellites. NASA itself has acknowledged its concern about SpaceX’s plans, embarking on the process of deploying a huge artificial constellation for its satellite Internet system. Elon Musk’s firm has already received permission to deploy 12,000, but has requested authorization to add 30,000.

What are we doing to avoid it? Beyond the initiatives to monitor space debris or directly eliminate it, over the last few years there have been some initiatives that seek to imprint a certain order and coordination on the generation of space debris. In 2002, for example, the Inter-Agency Debris Coordination Committee (IADC) published guidelines for “space debris mitigation”, a sort of basis for establishing legislation and technical standards. The measures include a commitment that the ships do not keep explosive fuel on board after their missions, carry out maneuvers to avoid collisions or the requirement that ships in low Earth orbit must retire after 25 years.

Universe Today and ESA images