Space Assets Critical to Defeat Hypersonic Threats.

• Author: Beu, Samantha
• Position: EMERGING TECHNOLOGY HORIZONS

Threats that can't be seen can't easily be defeated--and if that threat is traveling at Mach 5, there are only minutes to make a decision.

Competitors already have operational hypersonic missiles--which have been demonstrated in the Russian invasion of Ukraine and the reported Chinese launch of a hypersonic glider off the Taiwan Strait--making the ability to detect and defeat such weapons a top priority for the Defense Department. Fortunately, there are efforts underway to do just that.

The Space Development Agency recently announced awards to L3Harris Technologies and Northrop Grumman to deliver 28 infrared-sensing satellites for a constellation referred to as the Tranche 1 Tracking Layer. This layer, designed for advanced missile warning and missile defense, is part of the larger national defense space architecture that will deliver sensing and data transport capability with a proliferated constellation of satellites in low-Earth orbit.

Proliferation is the key; an architecture of hundreds, or even thousands, of small satellites orbiting at altitudes less than 2,000 kilometers will provide better resiliency against incoming threats. Simply put, by increasing the number of targets, an adversary's chances of success against the whole network will be significantly reduced.

The agency has also argued convincingly that a mesh network in low orbit is more cost-efficient and easier to deliver and replace than current defense assets operating in higher orbits. Low-Earth orbit offers other advantages for space-based observation, as the closer proximity to Earth provides higher-resolution imaging for remote sensing.

Each tranche of the satellites will be delivered in two-year cycles, building on the capabilities of the previous iteration. Tranche 1 satellites are planned to launch in fiscal year 2024 and will be equipped with four optical inter-satellite links to enable high-speed communication and data exchange through point-to-point optical beams. These cross-links will allow the satellites to locate and track one another, forming a highly secure space-based communication network.

Advancements in infrared sensor technology being championed by the agency also promise enhanced resolution imaging. As noted in a June report from the Center for Strategic and International Studies, "Boost-Phase Missile Defense" by Ian Williams, Masao Dahlgren, Thomas G. Roberts and Tom Karako, multiband/multi-megapixel focal plane arrays can be used to develop...