Originally published by Space Intel Report on September 11, 2024. Read the original article here.

PARIS — Operators of satellite constellations including Eutelsat Group’s OneWeb, Globalstar and the coming Telesat Lightspeed routinely cite the fact that their networks fly above the heavily trafficked portions of low Earth orbit where satellite and debris density is much higher.

It’s safer there. But to get to that peaceful place you need to pass through the bad neighborhoods below. Is that a serious issue?

OneWeb has launched 636 satellites into a 1,200-kilometer-altitude orbit and deorbited two of them. The constellation is spread over 12 orbital planes, and OneWeb says it has maintained several kilometers between each plane “so that we don’t need to maneuver regularly around our satellites,” said Kimberly Baum, Eutelsat Group vice president for spectrum engineering and strategy.

“We selected an operational altitude without significant debris, and which avoids overlap with other operational systems,” Baum said Sept. 10-11 at the Space Sustainability 2024 conference organized in Geneva by the International Telecommunication Union.

But as is typical of constellation operations, the OneWeb satellites are deposited by their launch vehicle to a much lower altitude and then use their own propulsion to climb to 1,200 km. It is during this climb that OneWeb gets a front-row seat on the challenges of lower altitude.

53,000 conjunction messages per day during orbit-raising

“To give you an idea of the magnitude of the problem we are facing, when our satellites are in the orbit-raising phase in the more congested parts of the orbit, our system processes, on average, 53,000 conjunction messages each day,” Baum said. “Of those, we determine that about eight of them are actionable, or that a maneuver is required.”

Baum was among many satellite operators attending the ITU conference — the first of its kind and illustrative of ITU’s recent move to address the topic of space debris, orbital crowding, collision avoidance and related issues head-on.

One of the themes emerging from the two-day season was satellite operators’ request for harmonized regulations worldwide.

Mario Neri, strategy and innovation director at Telesat, whose 198-satellite Lightspeed constellation will operate at 1,300 km, cited the example of human casualty risk of satellite pieces falling to Earth.

The U.S. Orbital Debris Mitigation Standard Practice stipulates that the risk of satellite components surviving atmospheric reentry and injuring someone would be no greater than one in 10,000.

France’s Law on Space Operations, which will have a large influence on the European Commission’s future EU Space Law, stipulates that for stellate constellations of more than 100 satellites, the cumulative human casualty risk ceiling is set at one in 100.

“If your constellation is greater than 100 satellites, in the French case you need to meet standards that are stricter than the U.S.,” Neri said. “If you want to serve both markets, how do you design your satellites?

If you design your satellites to be fully demisable — and this is the target of Telesat — then probably the problem is not as big. But do you always comply with the strictest rule? It may be more expensive and not in line with your business case,” Neri said.

Another issue: When and whether to oblige operators to use active debris removal technologies — now being developed but nowhere near being proven — to physically remove satellites from orbit if they fail.

Neri said there needs to be a bridge “between these technologies and the regulations mandating the technologies. We need to be sure the technology is mature and proven, both technically and economically.”

It’s one thing to advise the use of active debris removal from 500 kilometers, where atmospheric drag is strong enough to work in favor of debris removal. But above 600 kilometers it’s another story. Should the rules apply the same way to constellations, whatever their orbit?

Eutelsat Group’s OneWeb is working active debris removal startups Astroscale and Starfish, and has a contract with the 22-nation European Space Agency (ESA), to test an Astroscale servicer to remove a OneWeb satellite and bring it down to an orbit from which it will be destroyed on atmospheric reentry.

Baum said this program demonstrates OneWeb’s commitment to space safety and debris mitigation. But she agreed with Neri that “We need to avoid having regulations get too far ahead of the technology.”

The Globalstar mobile satellite services constellation, which operates from 1,414 km, is confronting this issue now. It has 17 satellites on order from Canada’s MDA Space, the first eight of which are scheduled to launch in 2025.

Regulations from the U.S. Federal Communications Commission (FCC) that will take effect Sept. 30 call for satellites to be removed from orbit within five years of retirement.

Globalstar’s existing constellation was launched with a debris-mitigation plan being imposed by the United States and France, both of which are licensing administrations for Globalstar. These rules obliged Globalstar to raise retiring satellites into “graveyard orbit” at higher altitude.

With the change in regulations, the next Globalstar satellites will be brought down to an altitude from which they will disintegrate within five years.

“All the satellites we launch in the future will orbit down because of [technology] advancements and the changes in the regulations put into place by our notifying administrations, the United States and France,” said Barbee Ponder, Globalstar general counsel and vice president for regulatory affairs.

“Now we have to wonder what happens when the satellite reenters the Earth’s atmosphere,” Ponder said. “The published rule is a one-in-10,000 chance that your satellite could injure someone. That risk must be much lower and regulators are trying to see that satellites are fully demisable and present no casualty risk.”

Originally published by Space Intel Report on September 11, 2024. Read the original article here.