Despite having the largest defense budget on the planet, the United States’ defense apparatus has recently found itself in a bit of trouble. As the U.S. devoted the vast majority of its resources to anti-terror and counter-insurgency operations for the better part of two decades, both Russia and China have been able to leverage America’s focus on fighting a very specific type of war to gain advantages in a number of technological realms. In effect, America grew too focused on the war it was fighting to keep pace with the tech needed to deter future wars.

Nowhere is this growing capability gap more apparent than in the realm of hypersonic missile technologies. Both Russia and China have already begun fielding missile platforms capable of achieving and maintaining hypersonic velocities (speeds in excess of Mach 5), and by the Pentagon’s own repeated admissions, America’s existing missile defense platforms are not capable of reliably intercepting missiles traveling at such speeds. In other words, two national level opponents now have a weapon system the U.S. not only doesn’t possess… but also one it currently doesn’t have the means to defend against if a conflict were to break out.

Of course, many questions remain about the reliability and accuracy of both Russian and Chinese hypersonic platforms. China’s anti-ship missile, the DF-21D, for instance, boasts an operational range of approaching one thousand miles, but little attention has been paid to how such a missile could accurately strike a ship-sized target from such a distance. Although China has demonstrated the missile’s accuracy on Nimitz class carrier mock-ups on land, they have yet to publicly acknowledge a single test at sea, let alone one against a moving target.

It goes without saying that, in order to have any chance at striking a carrier sized vessel in the open ocean, the missile would need to rely on a complex data link that bridges targeting information from multiple assets, likely including satellites, drones, and potentially even Chinese ships. How effectively China has overcome this technological hurdle is yet to be determined, but because the program has been moving forward for the better part of a decade already, the U.S. Navy can’t afford to assume China has yet to resolve its targeting issues.

“The Chinese have been thoughtful in their missile development. They have focused on tactical precision guided systems that could be really influential in a conventional fight,” said Michael Griffin, the Undersecretary of Defense for Research and Engineering. “The Chinese would hold our forward-deployed assets at risk. And that’s something to which we have to respond.”

Countering the threat of a new military technology often comes in two forms: first, replicate or match that new technology so your opponent knows you have the same ability to strike at them, and second, develop commensurate defense systems that can mitigate the threat posed by the new technology. Nuclear tipped intercontinental ballistic missiles (ICBMs), for instance, are the sort of platform that you can never totally remove from the table in terms of the threat posed, but having an arsenal of your own nuclear weapons ensures anyone inclined to launch a strike is aware that nukes will be headed their way as well. Couple an effective defense apparatus with the guarantee of counter-strike, and you have the recipe for an effective form of system-level deterrence. Currently, the United States Air Force estimates that America is about two years away from initial testing on a hypersonic missile platform to call its own, and more worrisome, the Pentagon recently acknowledged that it’s at least five to ten years away from establishing a way to defend against these missiles.

“Our response has to be a proliferated space sensor layer, possibly based off commercial space developments,” Griffin said. His concept is not to rely on large, expensive and time consuming “exquisite” satellites like the United States has traditionally maintained, but instead, he believes smaller, less expensive satellites could create a web of missile detection coverage that would be more resilient than a few, highly advanced platforms. Damages or destroyed satellites could be easily replaced, and using small, inexpensive ones means the web could be large enough to compensate for lost assets by rearranging them in the short term. Thanks to the comparably small dimensions and weight of these small satellites, it would also cost less to get them into orbit — likely by way of commercial rocket launches.

Although Lockheed Martin is nearing completion on the Space Fence, which uses ground-based radars to detect the movement of orbital bodies, Griffen cautions that ground-based radars aren’t the answer to the hypersonic threat, even if they do enter into low earth orbit along their parabolic trajectories.

“You would need a lot of radars that are very expensive, and themselves become targets,” Griffin said. “That’s not an acceptable defensive posture. The only way to see these things coming is from space.”

Although it would be expensive to launch a constellation of small satellites tasked specifically with monitoring for hypersonic missile launches, it would certainly be cheaper than building new, large platforms for the same task. While the U.S. already has a series of satellites in orbit that look for ballistic missile launches, hypersonic platforms produce significantly less light than an ICBM does upon launch, making their detection harder to manage from space with existing platforms. However, despite this challenge, Griffin points out that the technology required already exists — it’s just a matter of making hypersonic missile defense a priority.

“We know that this can be done,” said Griffin. “To me, this is not a technology challenge, this is a policy decision. Is the United States going to deploy a space layer so we can track the Chinese hypersonic threat from cloud break forward? The answer had better be yes.”

While there has been discussion about mounting space-based interceptors for America’s missile defense, Griffin pointed out that such a methodology wouldn’t be effective against hypersonic missiles. While some do follow the arched trajectory of traditional missiles, others travel at a nearly completely horizontal axis, near to the surface of the earth. In either event, attempts at space-based intercepts would likely fail — but early detection could bolster the effectiveness of surface level defense strategies like lasers.

“The future of missile defense, especially in acquisition, tracking and assessment of threats resides in space,” said Kenneth Todorov, Northrop Grumman vice president of missile defense solutions. He also previously served as the deputy director of the Missile Defense Agency. “Ground systems are still relevant, but in the future, the space layer is an imperative.”

Featured image: In the small satellite space, an intrepid team at NASA has figured out that a stock Android phone can work just fine as a low-cost satellite (it has a better processor than many satellites, and decent multi-axis sensors and GPS. They already know it works in a vacuum.) This picture shows such a phone mounted in a cubesat chassis with extra batteries and a yellow metal tape measure for an antenna. | NASA Ames Research Center