Greaves: “We believe the hypersonic threat is real. The United States will have to be prepared. And space will be a big part of that.”

WASHINGTON — Air Force Lt. Gen. Samuel Greaves, director of the Missile Defense Agency, says he has the full backing of Undersecretary of Defense for Research and Engineering Michael Griffin to move ahead with the development and testing of sensors in space that would fill blind spots in the nation’s antimissile defense system.

The Pentagon hopes to have funding approved possibly next year to begin work on a network of missile-watching satellites amid new warnings that Russia is testing hypersonic ballistic glider weapons that today would be undetectable after the initial boost phase of their flight.

Greaves calls hypersonic weapons a “real threat” that could challenge the United States as soon as five to eight years from now. But he cautioned that the Pentagon has a spotty track record developing satellite constellations and should not rush to deploy a new system until it has considerable proof that the technology works, and that cost estimates are realistic.

“We will prove the technology before we jump into a major program,” said Greaves, a former commander of the Air Force Space and Missile Systems Center who is deeply familiar with troubled space programs from years and decades past.

“We will not repeat AEHF, SBIRS, GPS 3, OCX,” he said, referring to a litany of Air Force satellite programs that collectively ran tens of billions of dollars over budget and were years behind schedule due to technological setbacks.

“We all know what happens when we overpromise and we underdeliver,” Greaves said during a question and answer session at a Mitchell Institute event Tuesday on Capitol Hill.

Greaves said a space sensor layer for missile defense is at the top of MDA’s priorities list. Although there is urgency to move ahead with this system, he wants to make sure all the bases are covered. “To go fast sometimes you need to go slow early on,” he said. “This is the slow part, doing the requirements, the architecture studies, the modeling and simulation, so by the time you make your decision, industry is ready to ramp up.”

The “vantage point of space” is essential to track the ultra-high speed gliders that Russia and China are developing, Greaves insisted. An effective defense may require a mix of satellites in different orbits. The Air Force already has the Space Based Infrared (SBIRS) satellites that detect missile launches from geostationary Earth orbit. A future missile tracking constellation would look down at the Earth and keep an eye on incoming weapons throughout their entire trajectory, from “birth to death.” Another “mid-course” sensor layer could be deployed to do discrimination, using the cold background of space to accurately classify targets and discriminate reentry vehicles from balloons or decoys.

“That’s our vision for space sensors,” Greaves said. “Griffin agrees with me. We believe the hypersonic threat is real, it’s not imagination.” The United States in only a few years will have to be prepared, he said. “Space will be a big part of that.”

If funding is approved and things proceed as planned, the space sensor layer could be deployed by 2025, said Greaves. An Air Force-led industry consortium is reviewing industry white paper for the missile tracking system. Other efforts are being pursued under the Defense Advanced Research Projects Agency’s Blackjack program that is developing a small-satellite constellation in low-Earth orbit. “We intend to make decisions later this year on a demonstration architecture,” Greaves said.

The space-based sensor layer for missile defense is an important system that the nation needs, he said. The Pentagon has given MDA extraordinary authorities to move ahead without getting bogged down in endless reviews and bureaucracy.

Greaves was asked whether a separate Space Force would do a better job overseeing space programs than the current organizations. Assuming it comes to fruition following the president’s directive, he said, “the focus on speed and intent of that Space Force will reflect positively with our mission.”

When the Space Force becomes a reality, Greaves said, “I see an organization, I see people, I see a community that goes to bed every night and wakes up every morning thinking about space,” he added. “They’re not just thinking about operations in space. They’re thinking about the acquisition process that delivers capability to the field in the requisite amount of time.”

The Space Force, if given similar authorities as MDA, would be “focused on the mission area,” Greaves said. “That is what allows you to go faster.”