Saving the Space-Based Radar

Issue Brief

A series of intelligence failures has underscored the need to improve U.S. collection and analysis capabilities. Part of that challenge is developing a global network of sensors that can continuously monitor indications of danger across the electromagnetic spectrum — from the low-frequency radio waves emitted by cellphones and laptops to the medium-frequency infrared waves produced by missile launches and artillery bursts to the high-frequency waves called visible light that make vision possible.

The U.S. intelligence community operates airborne and orbital sensors capable of collecting information in each segment of the spectrum. Most of these sensors are “passive,” meaning they collect whatever energy an enemy is emitting and concentrate it for analysis. But there are drawbacks to simply listening for an adversary to tip you off to his intentions, so the U.S. also operates a variety of “active” sensors that bounce their own signals off targets in order to track or characterize them.

Radar is the most common form of active sensor used by the military. Many people are familiar with the way in which radars transmit signals that reflect back from aircraft to allow tracking of their move-ment. Fewer people realize that the same principle of variable reflectivity can be used to take pictures through darkness and clouds, or to track moving ground targets. With the right sensors and processors, downward looking radars on planes and satellites can collect startling amounts of information. For example, a single “Joint Stars” aircraft can monitor all the traffic in a Washington rush-hour.

For decades, warfighters have dreamed of accomplishing that feat on a bigger scale — by orbiting a constellation of space-based radars that could track ground vehicles over vast swaths of the earth’s surface. Such radars would have a broader field of view than any airborne system, and would seldom encounter the interference from terrain features that sometimes blocks the view of sensors on planes. A space-based radar couldn’t offer the same detail as Joint Stars because it would be further away from targets, but by combining airborne and orbital sensors, an integrated system would provide both great reach and great resolution.

The Bush Administration identified space-based radar as a critical next-generation technology during the 2001 Quadrennial Defense Review. It proposed an ambitious plan to begin fielding an operational system within ten years. However, the plan was eviscerated by congressional appropriators this summer, who took away most of its funding and removed it from the procurement track. The appropriators’ action wasn’t surprising in light of uncertainties surrounding the program and poor lobbying skills at the Pentagon. But space-based radar shouldn’t be allowed to die, because it is a unique intelligence-gathering tool well suited to emerging threats.

Policymakers need to get space-based radar back on track — not by just repeating their arguments, but by listening to what the appropriators said in cutting the program. What is the concept of operations? How can the competing needs of military and intelligence-community users be reconciled? How will the system mesh with other collection assets? And finally, how can this unique capability be acquired without undercutting funding for other collection programs? Policymakers should have credible answers to such questions before they return to the Hill, because space-based radar really is a transformational capability.