Acting Defense Secretary Patrick Shanahan on Wednesday said his pitch to skeptical lawmakers on the need for a U.S. Space Force is that the Pentagon needs to move fast to keep up with pacing threats from Russia and China in space.
But could the sixth military branch eventually grow to better execute its purpose?
Speaking to audiences during a Center for Strategic and International Studies event in Washington, D.C., Shanahan said he envisions "15,000 to 20,000" individuals defending and protecting U.S. interests in the domain. In its fiscal 2020 budget proposal, the Pentagon said the branch will have 15,000 people, making it the smallest of any service.
While the Space Force will not need roughly $12.9 billion over five years to resource personnel and infrastructure for the branch like the Air Force originally proposed, Shanahan said the $2 billion over the same timeframe proposed to Congress is a "parametric estimate," meaning one that uses historical cost information and analysis of previous conditions to arrive at a figure.
"I'd say our $2 billion dollar number is a good parametric estimate. It's really more of a top-down number than it is a bottoms-up number. For the purposes of moving at speed you parametrically generate a number," the acting defense secretary said in a conversation with CSIS's Todd Harrison.
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Speaking to the Air Force's near-$13 billion estimate last fall, Shanahan said the service "just had different assumptions."
"I think over time it had growth factored into it," he said.
By comparison, U.S. Special Operations Command requested $13.6 billion for fiscal 2019, a 10.6 percent increase from its $12.3 billion request the previous year, according to the Tampa Bay Times.
"In the department we’re really going to do a bottoms-up approach to cost. Cost grows if you don’t limit it. To me, it's like, we need to cap it," Shanahan said Wednesday of Space Force costs.
He continued, "If we do the top-down approach in terms of normal equities, traditional structures, I think it will probably grow. That's what normally happens. I think we have to be very thoughtful. But remember, this is much smaller."
"I think we'll get the cost piece right," Shanahan added.
Outgoing Air Force Secretary Heather Wilson in September sent top Pentagon leadership her ideas, which included integrating and realigning major programs, including increased integration with the National Reconnaissance Office.
To date, the Pentagon's proposal does not include incorporating intelligence agencies such as the NRO into the Space Force. But the service would take over some NRO functions currently executed by the Air Force, according to the proposal. There is potential for these agencies to be added later, DoD officials have said.