The Space Force Is Launching Its Own Swarm of Tiny Satellites

Defense satellites used to be big, costly, and “juicy” targets for attack. Now the Pentagon is aiming for a more resilient network of nearly 1,000 mini orbiters.

Four years after it was formed, the US Space Force has begun deploying its first satellite network. For the military, it marks a significant shift from relying on a handful of powerful, expensive satellites to a swarm of smaller, cheaper ones. From the Pentagon’s perspective, they’ll be a harder target for rivals to strike; a missile or a laser attack might take out an individual satellite, but would do little to weaken a whole swarm.

“Historically, the Department of Defense has been investing in billion-dollar Battlestar Galacticas that are big juicy targets,” says Derek Tournear, director of the Space Force’s Space Development Agency. “We wanted to go to an architecture that gave us resilience against threats and that we could upgrade rapidly every two years.”

The new satellites are for defensive purposes, focused primarily on missile tracking, data transfer, and communications between the satellites and their ground systems. The first 10 members of the fleet were lofted into low Earth orbit on April 2, and 13 more are planned to launch in late August from Vandenberg Space Force Base in California.

The agency plans to accumulate 28 satellites for the batch to be launched this year, which they call “Tranche 0.” These will mainly be used for testing and demonstrating these satellites’ technologies and training people to use them. Tranche 1, made up of more than 160 satellites, will follow in late 2024. Those will be operational, meaning they’ll be used for tracking ballistic and hypersonic missiles, especially with an eye out for those from China, Russia, and North Korea. Within a few years, the agency will have nearly 1,000 in orbit.

The Department of Defense currently relies on about 10 missile defense satellites in geosynchronous orbit, which means their orbits keep pace with the Earth’s rotation at an altitude of about 22,000 miles. Flying the new swarm in low Earth orbit, which is only 600 miles above the ground, will improve their detection sensitivity and the timeliness of their missile warnings. 

Their diminutive size—about an eighth that of current satellites—is part of their advantage, as they’re cheaper and faster to develop and launch. “As threats to space expand, we can no longer rely on a strategy of putting most of our capabilities into these few large exquisite satellite systems. Now the DOD is taking the approach of building many systems on shorter timelines,” says Kari Bingen, director of the Aerospace Security Project at the nonprofit Center for Strategic and International Studies, whose funders include some US-based aerospace companies and military contractors.

While this is entirely a military operation, the Space Force is buying the satellite technology from private companies under contract. One swarm of the new satellites, provided by SpaceX and Florida-based L3Harris, will be charged with missile tracking using their wide field-of-view sensors. Another group, provided by Lockheed Martin and colourado-based York Space Systems, will be relaying data between ground systems and the spacecraft. The agency will add other networks to the mix in about two years, including satellites from Northrop Grumman, according to Jennifer Elzea, an SDA spokesperson.

The approach of using many small satellites together, rather than a handful of large ones, initially faced some resistance within the military—it’s a big change from the way the Pentagon has operated for decades. “It’s a bit of a culture shock,” Bingen says. But when Russia invaded Ukraine in 2022, Ukraine and its NATO backers began making use of thousands of small, networked satellites, including SpaceX’s Starlink for broadband, Maxar’s and other companies’ for optical and radar imagery, and GPS. While Russia has invested in anti-satellite missiles, lasers, and electronic weapons, none of these are suited for taking down a swarm. That demonstrated the utility of this kind of constellation, says Brian Weeden, director of program planning at the Secure World Foundation, a nonpartisan think tank based in Broomfield, colourado. “Why isn’t Russia blowing up Starlink satellites?” he asks. “They have the capability, but it’s just not going to matter.” 

Still, flying in relatively congested low Earth orbit could make the swarm vulnerable to collisions with other satellites and bits of space junk, like derelict spacecraft and shrapnel flung from previous anti-satellite missile tests. However, they won’t overlap with the orbits of major commercial constellations; they’ll operate above Starlink satellites and below OneWeb’s network.

If the 2024 budget the Space Force has proposed to Congress becomes a reality, it will pump some $4 billion into these satellite systems next year, about double the amount of previous years. After that, the agency is requesting about $5 billion annually through 2028, Bingen says. Congressional approval of this growing budget would be a sign of broad US government support for this new military strategy. (For comparison, this four-year budget for new satellites would add up to two James Webb Space Telescopes.)

The Space Force’s satellite constellations are launching just as the US’s rivalries with China and Russia are escalating. All three countries have been expanding their military capabilities in space, including investing in satellites and technologies that could be used to attack them. There is very little diplomacy or communication between the militaries of the US and China, other than warnings of close encounters between objects in orbit, Weeden says. Even the two countries’ civilian space programs are restricted from cooperating with each other, thanks to a policy called the Wolf Amendment. 

One of the motivations for building this satellite network is the development of faster-moving hypersonic missiles, which China and the US have both tested over the past couple of years. Hypersonic missiles travel at five times the speed of sound or faster, and they fly at much lower altitudes than intercontinental ballistic missiles, or ICBMs. ICBMs rely on booster rockets to blast them through the Earth’s atmosphere. Then the warheads have free flight through the edge of space and only reenter the atmosphere near their target. On the other hand, hypersonic glide vehicles, as they’re typically called, need to continually use fuel to travel through the atmosphere, which is denser than space. As a result, their exhaust plumes and aerodynamic heating during flight make them visible to infrared detectors, says David Burbach, a national security affairs expert at the US Naval War College in Newport, Rhode Island. The new satellite swarms will be equipped with infrared detectors, while the military continues to make use of ground- and sea-based radar sensors to detect ballistic missiles.

By some counts, the Pentagon’s current missile defense systems have only achieved a 50 percent success rate in tests. It’s possible that the new satellite swarm could improve these systems by providing faster, more accurate data. But, Burbach argues, it’s the Space Force’s shift toward constellations of smaller, cheaper satellites that’s most notable: “I see this more as a culture change than a capability change.”

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