Space Junk Removal Is Not Going Smoothly
A space age community tragedy is unfolding right under our noses – or really right above our heads – and there is still no consensus on how to stop it. For more than half a century, humans have been throwing objects into near-Earth orbit in ever greater numbers. And with a few significant restrictions on further launches into this increasingly congested realm, the prevailing stance has been persistently permissive: there always seems to be room for another in orbit.
After so many decades of building high-speed glitches in the form of spent rocket stages, stray bolts and paint chips, solid rocket motor slag, dead or dying satellites, and the scattered fragments of anti-satellite tests – all individually damaging or destroying other assets – low-Earth orbit is on the verge of becoming too crowded to feel good. And the problem is only going to get worse as more and more satellite mega-constellations emerge that require thousands of spacecraft, such as SpaceX’s Starlink, a broadband Internet network. Starlink is just one of many similar projects: Another mega-constellation of a company called OneWeb is already being deployed. And Amazon’s Kuiper project aims to create a mega-constellation of up to 3,200 satellites in the near future.
As congestion has increased, tight connections must also be made between assets in circulation. The International Space Station, for example, regularly changes orbit to avoid potentially dangerous debris. Worse still, the risk of collisions leading to dangerous garbage and exacerbating an already bad situation has increased. Look at the February 2009 inlet between a dead Russian Cosmos satellite and a commercial Iridium spacecraft that produced an enormous amount of debris.
Finding ways to remove at least some of all space debris should be a top priority worldwide, says Donald Kessler, a retired NASA senior scientist on orbital waste research. In the late 1970s, he predicted the possibility of a scenario known as Kessler Syndrome: As space debris increased in density, a cascading, self-sustaining runaway cycle of collisions can emerge, creating debris and ultimately into low-Earth orbit could lead to dangerous to support most space activities.
“There is now consensus within the community that the rubble environment has reached a tipping point where the rubble would continue to increase even if all launches were stopped,” says Kessler. “It takes an Iridium-Cosmos-type collision to get everyone’s attention. That’s what matters … and we’re overdue for something like this to happen. “
The Kessler syndrome “has already started,” says the rubble expert. “There are always collisions – less dramatic and not on a large scale,” adds Kessler.
Up and out
Kessler’s nightmare scenario has resulted in a lack of possible solutions for flushing debris: nets, laser beams, harpoons, giant foam balls, blasts of air, tether straps and awnings, and garbage collection robotic arms and tentacles have been suggested as solutions for taking out our orbital debris.
A new addition to addressing this worrying condition is Astroscale Demonstration’s (ELSA-d) End-of-Life Services mission. ELSA-d is a two-satellite mission developed by Astroscale, a Japan-based satellite services company. It consists of a “servicer” satellite, designed to safely remove debris from orbit, and a “client” satellite, which also acts as an object of interest. The project aims to introduce a magnet system that can detect stable and even tumbling objects, whether for disposal or for maintenance in orbit. After a multi-phase test agenda, the servicer and the customer will then desorb together and dissolve during their fiery immersion in the earth’s atmosphere.
ELSA-d is now in orbit. The mission was launched on March 22nd via a Russian Soyuz rocket that threw the shovels of other hitchhiking satellites into space. After launch, Astroscale Founder and CEO Nobu Okada said ELSA-d will demonstrate the ability to dispose of waste and “drive regulatory developments and drive the business model for end-of-life and active waste removal services.” The launch is a step towards “safe and sustainable development of space for the benefit of future generations,” he said.
While ELSA-d and other technological demonstrations of its kind are undoubtedly positive developments for clearing debris in orbit, they should not be confused with panaceas. Despite their modest successes, such missions are unable to cope with the current dynamic dilemma and the proliferation of space debris continues essentially unabated.
“From my point of view, the best way to deal with space debris is not to create it in the first place,” says TS Kelso, scientist at CelesTrak, an analytical group that orbits objects that orbit the earth. “As with any environmental problem, it is easier and far cheaper to prevent pollution than it is to remove it later. Stop keeping things in orbit after they have completed their mission. “
There is simply no “one size fits all” solution to the problem of space debris, says Kelso. Removing large missile bodies is a much different task than removing the equivalent mass from much smaller objects that are in a wide range of orbits, he observes. In the meantime, innovations from companies like SpaceX are drastically reducing startup costs and opening the floodgates for far more satellites to enter low-earth orbit, where some inevitably fail and become drifting, debris-generating dangers (unless ELSA-d – eliminated) like space tug). “Many of these operators are beginning to understand how difficult and complex it is to keep dodging the growing amount of waste.”
Space debris ranges from nanoparticles to entire spacecraft like the European Space Agency’s Envisat, which is the size of a double-decker bus and high on the hit list of all removers, says Alice Gorman, space archaeologist and space debris expert at Flinders University in Australia.
There are also items like Despin weights, which are solid lumps of metal, and thermal blankets, which are paper-thin. “They cause different types of damage and may need different strategies to repair them. There’s no way that a unified approach can do this, ”says Gorman.
The greatest risks, she says, come from dirt particles between one and 10 centimeters in size. “There are far more of them than entire non-existent spaceships, and the likelihood of a collision is far greater,” says Gorman. “While debris this size may not cause catastrophic breakup, colliding with them can certainly damage working satellites and create new debris particles.”
Gorman turns her attention to satellite mega-constellations and is concerned about their impact in a near-earth orbital environment that is already congested. “We also know that orbital dynamics can be unpredictable,” she says. “I want some of these mega-constellation operators to release their long-term collision modeling as more and more satellites are launched.”
There is no doubt that actively removing debris in orbit is a technical challenge, says Gorman. “The big problem, however, is that any successful technology that can remove existing debris can also be used as an anti-satellite weapon,” she says. “This is a whole different can of worms that requires diplomacy and negotiation, and most importantly, trust at the international level.”
In fact, the ability to get used to spacecraft and perform maintenance or sabotage while in orbit has drawn a lot of interest from military planners in recent years, says Mariel Borowitz, associate professor at the Georgia Institute of Technology’s Sam Nunn School of International Affairs. “These rapidly advancing technologies have the potential to be used for peaceful space activities or for space warfare,” she says. “Given the dual purpose of their skills, it is impossible to know in advance exactly how they will be used on any given day.”
Take up space
According to Moriba Jah, an orbital debris expert at the University of Texas at Austin, the space debris removal business model is currently not monetizable and is more of a “PowerPoint conversation” than a real marketplace.
“I think people hope that the government will basically come to some common sense in order to create and create a marketplace for industry to participate in such activities,” says Jah. To achieve this, the space nations must agree that near-Earth space is an ecosystem like land, air and ocean. “It’s not infinite, so we need environmental protection,” he says.
Jah has an eye on space sustainability metrics that are similar to a carbon footprint. “Let’s call it a ‘space travel’ footprint,” he says. “We need a way to quantify at what point an ‘orbit’ becomes saturated with traffic so that it can no longer be used. Then you can assign a premium on objects and talk about the non-consensual removal of dirt. Perhaps there is a penalty for the sovereign owner of his dead property that claims the capacity of an orbit. This could definitely create a marketplace for space object removal technologies to thrive. “
A classification scheme for objects in the room is also needed. Such a taxonomy, says Jah, would help figure out what kinds of technologies are required to remove various orbital perturbation trees.
As for the big picture, Jah says it’s a simple numbers game: the launch rate exceeds the rate of space objects re-entering the earth’s atmosphere. “It’s not a great kind of energy balance,” he adds.
Unfortunately, Jah says, policy makers are still slow to respond to the problem. Although events like the 2009 Cosmos-Iridium collision generate massive amounts of debris, they are still quite rare for now.
“In my opinion, that 2009 collision was synonymous with passengers on the Titantic bumping off an iceberg and then having a band playing on deck,” says Jah. “With dangerous debris in orbit, things are already going bad because we haven’t changed our behavior.”