WASHINGTON — The Pentagon is moving forward with plans to build a constellation of warning satellites to defend the United States and allies from missile attacks. Congress also directed the Pentagon to study the possibility of deploying weapons in space to shoot down enemy missiles.
Undersecretary of Defense for Policy John Rood said the Defense Department is following congressional orders and looking at the technological and security implications of putting interceptor missiles in space. But he cautioned the Pentagon is not yet ready to endorse the idea or proceed ahead with a program.
“Those are bridges yet to be crossed,” Rood said on Tuesday at a conference on Capitol Hill organized by the Missile Defense Advocacy Alliance.
A decision on whether the United States should deploy defensive weapons in space is “some time away given the level of examination” that is required, Rood said.
Congress is directing the Pentagon to step up efforts to develop a space-based missile shield at an especially sensitive time for space security. The Trump administration has warned that the United States could see its dominance in space challenged by China and Russia. As countries develop new “counter space” technologies and space becomes militarized, the administration argues, the United States needs to strengthen its capabilities to deter attacks, and also be prepared to fight back.
Arms control experts and watchdog groups have warned against an escalating space arms race but the U.S. government contends it is taking only defensive measures.
The Pentagon has been particularly alarmed by advances in China’s and Russia’s hypersonic weapons, which are not detectable by current U.S. missile-defense radars. Hypersonic glide vehicles fly into outer space and back into the atmosphere in unpredictable trajectories, unlike ballistic missiles. The Defense Department concluded that only sensors in space can spot these threats accurately and early enough so they can be shot down.
Rood insisted that sensors are not weapons. “If the U.S. pursues a space sensor layer, it watches, it detects what others are doing. It’s not a provocative act,” he said. “It’s no different than what we’ve done for decades.”
This is about “having the ability to prepare,” he said. “If we’re attacked, we can deal with it, that’s what we want,” he added. “I don’t think having a sensor capability is a sea change for the United States.”
A layer of interceptor missiles in space would be a different story. An international accord prohibits the deployment of weapons of mass destruction in space. A provision in the fiscal year 2018 National Defense Authorization Act requires DoD to explore options for both sensors and interceptors in space. The department is complying with that order, said Rood. “But we are not yet in a position where we would announce some programmatic changes. We’re in the examination phase.”
There are still “strategic and policy questions that need to be answered,” said Rood.
A prominent advocate of space-based missile defense is Undersecretary of Defense for Research and Engineering Michael Griffin. He explained that current defenses only work against ballistic missiles but not hypersonic gliders. “We can’t hit a target we cannot see coming,” he said. If the Chinese were to launch a hypersonic weapon, said Griffin, “We would not see it coming until it’s too late.”
Griffin also believes the United States should have its own offensive hypersonic strike weapons. The Pentagon has awarded Lockheed Martin a billion dollars worth of contracts to develop hypersonic missiles.
Griffin said the United States’ military dominance is being challenged and the nation has to step up its space and missile defense capabilities.
“Policy is not my thing,” he noted.
“We have to go to space both for the sensor layer and the ability to project power,” he said. Griffin fired back at critics who estimated a space-based missile shield would cost $100 billion. “I am very tired of people saying we cannot afford it,” he said. He estimated that based on rough costs of $20,000 per kg, a layer of 1,000 interceptors each weighing 1,000 kg would cost $20 billion. “We’ve paid a lot more and gotten a lot less in the Defense Department,” Griffin said.
He later explained that he’s not necessarily advocating a system of 1,000 interceptors. Many details such as the number of weapons and the orbits where they would be placed have not yet been investigated. “I do what engineers do, which is try to bound the problem,” he said. “As we study the problem we will produce answers.”
The United States should not be worried about upsetting China or Russia, said Griffin. “When you have President Putin on TV bragging about his multi-thousand kilometer hypersonic nuclear strike weapon, and you have China making several dozen successful hypersonic tests, that’s great power competition,” he said. “Somewhere well down on that priority list is caring about what people think. We just cannot afford to do that.”
Griffin said the Pentagon has a window of opportunity now to advance these technologies with Congress on its side. “Congress is directing us to study these things,” he said. “The shift in congressional policy since my earlier days is both dramatic and refreshing. I hope the environment we are in now lasts for a while.”
The director of the Missile Defense Agency, Lt. Gen. Samuel Greaves, said he expects decisions to be made later this year on the architecture for a space-based sensor layer for hypersonic defense. Several industry proposals are being evaluated, as well as a concept developed by the Defense Advanced Research Projects Agency. DARPA is developing an experimental constellation of commercial satellite buses in low-Earth orbit that would serve as platforms for military sensors.