There is a growing mess in space.
Low-Earth orbit, a narrow space relatively close to the Earth’s surface, is filled with thousands of tons of space debris – objects as large as decomposed satellites and used rockets to paint nuts, bolts and stains.
On Saturday, a new mission will be launched aimed at clearing up some of the debris that is languishing in orbit around the planet. The mission, known as ELSA-d, will test technologies to capture an object in a low-Earth orbit and move it to a lower altitude, where it will eventually burn harmlessly in the Earth’s atmosphere.
If successful, ELSA-d could pave the way for future commercial services that reduce the amount of clutter in space and promote more sustainable operations in a job.
Over the past few years, concerns about space debris have increased as the low-earth orbit has become more pressing, and as society’s reliance on satellite systems for telecommunications, GPS, and numerous other everyday functions has increased. Population in an orbit is also exacerbated by companies such as SpaceX and OneWeb compiling large “mega constellations” of Internet satellites around the earth.
Pieces of space debris, flying up to 18,000 miles per hour through an orbit, could threaten other functioning spacecraft and pose safety risks to astronauts on the International Space Station.
Astroscale, the private company behind the ELSA-d mission, hopes the technologies will open up a market for the removal of orbital debris.
“It’s an issue like plastic in the sea,” said John Auburn, Astroscale’s managing director in the UK. “We’ve been working for eight years to turn a difficult problem into a business.”
The ELSA-d mission is expected to kick off the Baikonur food modroom in Kazakhstan at 2:07 a.m. ET on Saturday. The technology demonstration will be carried out by two spacecraft that will be launched together: a “satellite satellite” of about 400 pounds and a “customer satellite” of 40 pounds used to simulate a piece of orbital debris.
Over the next few months, the two satellites will separate and then embark on an extensive game of orbital cat and mouse. In a series of tests, the server satellite will attempt to assemble with the client spacecraft, dock the object and then release it.
“It’s very complicated because you have to match exactly the movement of the spacecraft you are climbing into,” Auburn said. “As a spacecraft with the International Space Station facility, it’s a very controlled maneuver. But if you try to ignite with a failed satellite, it can tumble and you have to get together very slowly, almost as if you were doing a dance.”
The mission will also test a magnetic coupler that can be fitted to future satellites before launching, providing a way to safely remove these spacecraft from orbit after being put into service.
ELSA-d will be operational for about six months. At the end of the mission, both the servers and client satellites are ordered to burn up in the earth’s atmosphere.
Aaron Rosengren, an assistant professor of mechanical and aeronautical engineering at the University of California, San Diego, said it would be critical to continued operations in space.
“Even though the space is large, the usable orbits are quite small,” Rosengren said. “If we have a higher and higher density of objects in these very narrow areas of space, it will lead to more collisions over time.”
One of the most striking examples of an orbital accident occurred in 2009, when an abandoned Russian satellite known as Cosmos 2251 broke into a US Iridium 33 communications satellite. The collision created a cloud of more than 2,000 pieces of space debris that was at least 4 inches wide.
It is estimated that these pieces of debris will remain in the orbit for decades or longer, posing collision risks that could further exacerbate the problem.
The International Space Station has been hit by space debris in the past, and over the course of the station’s history, NASA has had to perform at least 26 special maneuvers to dodge transverse objects that have wandered too close to the orbit. According to former NASA administrator Jim Bridenstine, the agency had to carry out three such maneuvers in 2020 alone.
“The @Space_Station maneuvered three times in 2020 to avoid clutter. In the past two weeks, there have been three possible conjunctions with great concern. Rubbish gets worse! ” Bridenstine tweeted on September 22, 2020.
These sensational events show the real danger posed by space debris, Rosengren said. Without the way to clear up the limited space around the earth, this valuable real estate could one day become unusable, he added.
“We may already be at that tipping point,” he said. “There are tens of thousands of objects in this region, but we do not know what the carrying capacity of orbits is. How many is too many?”
