Peeling Back the Onion on Space Crowding: Myths vs. Reality

As more countries and constellation providers launch into space, the urgency for better space situation awareness and potential collision risks grows. Yet the question of whether space is really crowded is hotly debated in the industry, with Low-Earth Orbit (LEO) constellation companies insisting there is room for everyone, and the overall community raising concerns that the orbital environment is filling up and increasing the potential of collisions.

“Crowded is a loaded term, especially when we're talking about space,” says Melanie Stricklan, co-founder and CEO of Slingshot Aerospace, an Austin, Texas, space sustainability company building a simulation of the actual live-space environment. “The spectrum environment is getting really crowded. That uncertainty continues to grow, and we have coverage gaps that are persistent.”

Objects actively tracked and cataloged in near-Earth orbit have increased steadily over the last six decades. The European Space Agency’s Space Environment Report 2022 has spotted more than 30,000 pieces of debris currently tracked by space surveillance networks.

Based on ESA models, there are likely more than 1 million objects larger than 1 centimeter, the report states.

Space is Reaching an Inflection Point

A new space sustainability report by McKinsey & Company in collaboration with the World Economic Forum notes that expanding space activities are beginning to outpace governance, introducing global dynamics that could create risks to continued international collaboration needed for a future thriving space economy.

McKinsey’s report finds that the number of active satellites in space has doubled over the last two years and by the end of the decade SpaceX’s satellite launches are expected to exceed the number of satellites the world has sent into space since Sputnik.

In addition, the report found that in 2021, 40 nations launched objects into orbit – double the number in 2015. And trackable orbital debris has increased by more than 80 percent in the last two decades — even before large constellations with planned footprints of thousands of satellites began entering orbit.

The U.S. Department of State described Russia’s anti-direct-ascent anti-satellite (ASAT) missile test last November that struck an inactive Russian satellite and propelled 1,700 more pieces of trackable orbital debris and hundreds of thousands of untrackable fragments into LEO “dangerous and irresponsible” and a long-term threat to satellites and other space objects vital to all nations’ security, economic and scientific interests. The incident led to space debris becoming a national security priority.

An earlier ASAT missile test by the Chinese to destroy its non-operational Fengyun-1C weather satellite spewed 3,000 fragments into LEO, with much of the debris expected to remain in orbit for decades, reported the Secure World Foundation.

According to LeoLabs, which operates a global radar network for precision tracking of objects in LEO, 38 percent of all high-risk conjunctions in the first four months of this year involved debris from these two tests.

“It is shocking that two events in 60 years are the cause of over a third of the current collision risk in LEO,” says Dr. Darren McKnight, a senior technical fellow at LeoLabs.

The Russian test last November led the United States to issue a unilateral moratorium declaration on anti-satellite missile testing.

But is space crowding strictly about the numbers? Not necessarily, observes McKnight.

“The number of objects is not necessarily a direct and perfect measure of how crowded a region is. It depends on the kind of objects, the size of objects, the intelligence of those objects and the ability of those objects to maneuver and the intent for them to maneuver. It’s about your ability to be safe,” says McKnight. “You’ve got to peel back the onion and see where the satellites are ― how do they operate? How well do they behave?”

He contends that the safest place to operate a satellite is 547 kilometers above Earth, the orbit of choice for Starlink satellites. Why? “They’re small, agile and quite aware of their surroundings and all the conjunctions.” He notes that other altitudes in near-Earth orbit carry greater risk even if they have fewer objects, because many of those objects tend to be larger, dead and without propulsion capability – creating a greater collision risk.

Marlon Sorge, a technical fellow at The Aerospace Corporation, recalls when only government agencies tracked space debris.

“Now, commercial companies are actively mapping LEO orbital trash, which is changing the paradigm of what we think we know about what’s going on in space,” he says.

Where is the Space Debris?

Space junk can range from a discarded rocket stage to a tiny chip of paint. How quickly it falls back to Earth depends on its altitude. Intact objects below 600 kilometers (375 miles) will orbit about 20 years before reentering Earth’s atmosphere, while pieces of debris above 1,000 kilometers (600 miles) will orbit for centuries. Knowing where space trash is collecting is becoming easier thanks to analytics and orbital debris tracking companies.

According to analysis by space insurance firm AXA XL, more than 120 Geostationary Orbit (GEO) satellites are operating beyond their design life. Failure of these older satellites in GEO poses a collision risk since they are unable to communicate or maneuver to a graveyard orbit. Approximately 62 satellites in GEO have been lost since 2000, and 86 have suffered major anomalies (42 percent within the first two months after launch), according to the insurer.

Christopher Kunstadter, global head of Space at AXA XL, predicts that a significant insurance loss due to a collision in orbit will have a chilling effect on the space insurance market as well as the overall space industry. According to AXA XL, the current failure rate of satellites by orbit is 1 percent in GEO, 12 percent in LEO among satellites under 140 kilograms, and 27.5 percent for cubesats.

The biggest collision risks are in LEO, where there are over 4,000 active satellites compared with 200 in Medium-Earth Orbit (MEO) and High-Earth Orbit (HEO), and 577 in GEO, according to insurer AXA XL. Analysis by AXA XL finds that the chance of a collision in LEO will grow seven-fold by 2030.

LEO Operators Policing Themselves

Today, the International Telecommunication Union (ITU) manages orbital resources globally, and its priority remains in one area: frequency management. That makes sense for GEO satellites, which must be kept physically separated to avoid interference. However, ITU’s focus on frequency issues also applies to the increasingly congested LEO orbital slots, with the UN agency not accounting for capacity concerns.

“It’s up to the companies to coordinate with their neighbors,” notes Pascal Wauthier, chairman of the Space Data Association (SDA), a satellite operator membership-organization on a mission to ensure that space is kept safe. SDA operates the Space Data Center (SDC) platform that gathers flight dynamics information from member companies and other available sources to allow conjunction assessments and warning services.

While LEO orbits are the most crowded, that doesn’t mean GEO isn’t facing debris challenges as well. Wauthier contends that the industry practice of re-orbiting their end-of-life satellite in GEO to a graveyard orbit 200 miles above active satellites is not sufficient given that the potential high number of small floating debris (less than 1 meter) now in that orbit and the likelihood of collision.

“The small fragments pose a debris hazard to active GEO orbiting spacecraft,” he says, warning that without tracking these fragments as well as real-time sharing of position information, even spacecraft with active propulsion control could get into trouble if another vehicle is doing a maneuver and not disclosing its intent.

The Aerospace Corporation, the United States’ only federally funded research and development center providing technical guidance and advice on space missions to U.S. military, civil, and commercial customers, is seeing more serious attention given to space debris and collision risk issues by the space ecosystem. In his three decades working in the space debris area, Sorge says there is a big difference in how orbital debris issues are talked about today compared with in the past.

“There is active interest in trying to deal with this problem. It’s on people’s minds and they’re worrying about it,” says Sorge, who serves as executive director of the Center for Orbital and Reentry Debris Studies. “While we have some rules and guidelines, they usually are not enforced at the international level.”

On a positive note, most large constellation operators largely “have been very conscientious of the orbital debris problem,” he says. A drawback, however, is how hard it is to keep up with the speed that things are moving.

“The challenge is mobilizing everybody, getting them to talk to each other, getting to talk across the barriers that there are that which have not decreased in the last year or two,” he says.

Space users across all sectors must adapt to the new realities by being more open about their satellites’ location and movement. While most industry players agree that there needs to be a unified approach to addressing space traffic management and space debris, they’re less in agreement on how, with many worrying that overly strict regulations could affect their ability to compete and grow.

25-Year Rule Needs to Go

Most industry players agree on one thing: the 25-year rule – NASA’s mandatory deadline for disposing of dead satellites in LEO within 25 years of their mission life – hasn’t kept pace with the growing population of LEO satellites and the technologies available to address the collision risks posed by accumulating space debris.

The timeline was founded on solid science originally: the observation that it takes nearly two solar cycles – where a single cycle lasts 11 years – to wash out the debris naturally from orbit. However, say experts, the mitigation guideline hasn’t kept pace with the growing population of LEO satellites or with technologies such as propulsion systems now available that offer more efficient ways to remove debris.

“In 2000, when the 25-year rule was codified, we had 400 operational satellites, and maybe 6,000 total objects on orbit. And now we have triple of the number of objects, and we have a factor of 10 more operational satellites,” says LeoLabs’ McKnight, observing that the rule basically gives operators the greenlight to operate a satellite for six months and then let it linger and be collision hazard for 25 years.

“25 years is ridiculous when you're talking about thousands and thousands of satellites,” adds Stricklan.

McKnight argues that the 25-year rule should be reduced to a one-year rule – when a satellite is no longer in use, it should immediately be brought below the space station altitude.

He and others compare the lack of leadership on changing policy to a lack of leadership and foresight similar to what occurred around global warming.

“Nobody wanted to make the hard decisions about things having to do with global warming because they wanted to see the data first,” says McKnight.

“People focused on climate change have been warning us for years that not acting until it’s nearly too late. Similarly, the space debris situation could intensify until there’s a big catastrophe,” Wauthier adds.

Observers worry that delaying policy changes will result in damage that will take decades to centuries to reverse. McKnight says in the case of space debris, it will linger for centuries, slowly raining down on new operational satellites.

More Communication and Transparency

Getting a handle on the issue will require a range of activities from R&D investments in technology to funding commercial capabilities and better information sharing.

“Owner-operators need to become okay with more transparency around their positional data than they have been before,” says Stricklan.

The Slingshot Aerospace leader says the space industry’s struggle with how to globally manage space debris could look to the aviation world for an example of a path forward. She notes that it took the disappearance of Malaysia Airlines Flight 370 before the aviation world got serious about automatically tracking aircraft positions globally.

Stricklan notes that it’s not just industry that needs to come together; agencies, too, must embrace better transparency.

“Governments, including our own, operate in different silos – it’s left over from the Cold War,” she says.

“Communication is actually a really a big part of the issue,” adds Sorge. “The better and more efficiently we can communicate, the more easily we can find solutions to the problems and actually implement those solutions,” he says.

Some promising developments include a voluntary rating system, Space Sustainability Rating (SSR) from the World Economic Forum, which scores space operators on the sustainability of their missions while encouraging and recognizing responsible behavior. The SSR is scheduled to be fully operational as of this June, according to a press release by the rating’s host organization, Space Center (eSpace) at the Swiss Federal Institute of Technology Lausanne (EPFL).

“The SSR will function like a LEED certification for buildings but apply to space operators and how responsible they are being in orbit,” explains Kunstadter of AXA XL.

The Urgency to Act

The Aerospace Corporation’s Sorge indicates that the time is now to take a unified approach to addressing space sustainability.

“In the old days, when there wasn't as much activity you could afford to make some mistakes, learn from them, and move on, but now, we can't really do that. We’ve got to work together and figure out the rules of the world for safe operations.”

Stricklan envisions a new international cohort forming to drive guidelines and levers across the world, and for it to succeed, the cohort will need to be non-defense focused and likely commercial led.

“It's going to take all of us to make a difference with sustainability, and we must work across government, civil and commercial lines to make that happen. If the right cohort comes along, they need to also make sure that they are catalyzing those relationships,” Stricklan concludes. VS