WASHINGTON – Multilayered connectivity – the ability to connect with different satellites in different orbits and frequency bands – lends resiliency and versatility to military operations, but seamless interoperability across systems remains a significant challenge, according to industry and government experts.

The U.S. military has traditionally relied on geostationary orbiting (GEO) satellites, government- and commercially owned, to deliver everything from targeting information to entertainment to deployed forces. But the last decade has seen a proliferation of commercial satellites in medium Earth orbit (MEO) and, most recently, low Earth orbit (LEO), and the military is eager to take advantage.

Currently, interoperability across satellite systems operated by different companies in different orbits and frequencies is limited, but military and industry officials gathered at the Satellite 2024 conference organized by Access Intelligence spoke optimistically of a future where a user with a single terminal can connect seamlessly across all these constellations. For example, the Defense Innovation Unit, a Pentagon organization created to tap the commercial sector’s latest technology advances, is promoting the Hybrid Space Architecture concept that would give warfighters the ability to “operate off of any constellation at any time and at any place,” said Bill Joo, Special Projects Engineer and Science & Technology Assistant Program Manager for U.S. Naval Warfare Information Systems Command.

But some industry executives cautioned that a lot of heavy lifting lies ahead.

Interoperability Is Easier Said than Done

“As we go to the multi-orbit, multi-constellation-type systems, there’s a growing demand for enterprise management control, network management, orchestration software, defined networking,” said Rick Lober, Vice President and General Manager of the Government and Defense Division of Hughes Network Systems. “I feel that the [U.S. Department of Defense] just continues to lag in that area.” Until improvements are made, the Pentagon will be stuck with “siloed systems” that don’t talk to each other, he added.

Rory Welch, Vice President of Global Government and Satellite Services at GEO satellite operator Intelsat, said orchestrating multilayered connectivity across networks, and integrating legacy assets into the mix, is a “huge challenge.”

Another challenge is connecting with satellites in LEO and GEO using a single terminal, notwithstanding recently reported progress in this area.

In a brief interview with Constellations, Lober said the electronically steered, phased array antennas required to connect with LEO satellites have difficulty connecting with GEO satellites.

Hughes is teaming with SES on a multi-orbit connectivity solution under the Air Force Research Laboratory’s (AFRL) Defense Experimentation Using Commercial Space Internet program. Hughes is providing the modems for the system.

“The challenges are, you have two bands – Ku and Ka – you’ve got different polarizations, and when you get to GEO you get some pretty low look angles,” Lober said. “And the problem with an electronically steered antenna is it falls off in gain very, very quickly.”

Satellite companies also must come together on standards, said Welch. “Today, it’s sort of a kluge effect where we’re having to piece together different services that weren’t necessarily meant to talk to each other, but the future will be much more seamless,” he said. “So, we’re working on things like connectivity standards.”

Satellite networks need to be integrated not only with one another, but also with the terrestrial grid, Welch said. Terrestrial network operators have set the example in that regard, he added.

“You look at how the wireless phone operators got together and figured out how to do that themselves,” Welch said. “I think that’s where we want to get to.”

Military’s Resiliency Requirements Keep GEO in the Mix

Recent years have seen a proliferation of satellites in LEO, with more constellations on the way. SpaceX’s 6,000-satellite Starlink constellation has been especially disruptive, leading some to question the ongoing relevance of GEO. But military officials at Satellite, citing threats to U.S. satellite systems, said GEO remains an integral part of the mix.

“We’ve got to be resilient to the threats that are out there and so obviously, if you put everything in LEO, you’re susceptible,” Lt. Gen Shawn Bratton, Deputy Chief of Space Operations, Strategy, Plans, Programs and Requirements at the U.S. Space Force, said in response to a question by Constellations following a March 18 keynote speech. “Employing capabilities in multiple regions – GEO, LEO, MEO, highly elliptical orbits – gives you a resiliency attribute.”

The threats satellites face today include cyber, noted Space Force Lt. Col. Christopher Cox, Space Data Network Branch Chief at the Office of the Assistant Secretary of the Air Force for Space Acquisition and Integration. “Having multiple systems creates multiple different cyber paths an adversary would have to take to go after those systems,” he said.

Different Orbits for Different Applications

Beyond resiliency, multilayered connectivity brings a variety of attributes to the table. Big GEO satellites, for example, are efficient at moving large amounts of data, but their high altitude – 22,300 miles (35,800 km) above the equator – creates signal delays, or latency, which can be problematic for some applications. LEO satellites provide low-latency connections for crucial communications that cannot tolerate delays but tend to have more limited capacity.

“The different orbits, obviously, have different attributes that lend themselves to different missions,” Clare Hopper, Chief of the Space Force’s Commercial Satellite Communications Office, said during a March 19 panel discussion. On the LEO side, the Space Force has strong relationships with SpaceX and narrowband LEO constellation operator Iridium that, coupled with declining terminal prices, have been invaluable for a variety of emergent communications needs across the globe, she said.

Lober said his company is supplying electronically steered antennas for Eutelsat’s 600-plus-satellite OneWeb LEO constellation and recently deployed its own Jupiter 3 GEO satellite, which he called the largest commercial satellite ever launched. For low-latency applications, data can be routed over an LTE or LEO network, whereas higher-throughput data that is latency tolerant will go over a GEO satellite, he said.

Latency-tolerant applications include providing Netflix and other entertainment to deployed forces, experts noted. Joo said the importance of keeping up morale among sailors isolated from their friends and families should not be underestimated.

“I don’t care how the bits get there,” Joo said. “If latency is an issue, we’ll find another way to solve it and that might be LEO, but GEO has a significant play.”

MEO satellites, meanwhile, offer high throughout with reduced latency and require less ground infrastructure than LEO constellations, said Todd Gossett, Vice President of Space and National Security Initiatives at SES Space & Defense, the government marketing arm of SES. In addition to being one of the world’s largest GEO satellite operators, SES operates the O3b/mPower broadband constellation in MEO.

“We’re not as low-latency [as LEO] but we’re low-latency enough to allow things like cloud connectivity, internet applications and telephony that isn’t completely jacked up because of the gap between phone calls,” Gossett told Constellations. “We’re able to do that with a handful of gateways.”

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