If the Defense Department sticks with a bare-minimum option to create a Space Force, it's possible it could keep new spending between $1.5 billion to $2.7 billion over the next five years -- a relatively economical $300 million to $550 million per year.
But that's a big if.
A new report from the Center for Strategic & International Studies laid out by its author Todd Harrison finds that if the Pentagon sticks to a streamlined plan of transferring money already allocated for space operations and personnel into a new military service, the costs could be relatively conservative in DoD spending terms.
"Most of this is just a simple matter of reorganization and whether or not you think that is worth it," said Harrison, director of the Aerospace Security Project at CSIS.
Harrison unveiled his proposal at CSIS in Washington, D.C., on Monday.
"The added cost is a handful of F-35s," he said referencing the 5th-generation Joint Strike Fighter, the cost of which recently fell below $90 million per jet.
Harrison's report largely disputes the U.S. Air Force's original proposal that the Pentagon will need roughly $12.9 billion over five years to resource the personnel and infrastructure behind the Trump administration's proposed Space Force.
"A lot of the numbers that have been out there are a five-year estimate of the additional cost of creating a new military service for space," Harrison said.
But Harrison noted he did not include the intelligence agencies, nor their budgets, and also left out a huge component of what for months has been said to be a foundational aspect of the separate service: a unified U.S. Space Command designed to operate like a combatant command for space; and the Space Development Agency for overseeing the contracting process and procurement of new satellites, among other space capabilities.
"These are separate decisions," he argued.
These estimates do not include new procurement, only existing space capabilities on which the Pentagon already spends money.
Harrison offered up three approaches the Pentagon could take: returning to a "Space Corps" idea originally proposed by Congress; a "Space Force-lite" idea, which builds on a Space Corps; and a Space Force-heavy option.
All three options would use 96 percent of space funding the services already include in their annual budgets.
The three options would work as follows:
- A Space Corps to be kept within the Air Force, composed of 27,300 military and civilian personnel at mostly Air Force space bases at a cost of $11.3 billion a year, with $300 million in new funding.
- "Space Force Lite," which includes most of the Air Force Space Corps infrastructure but adds a few Army and Navy units and personnel that would amount to 35,800 military and civilian personnel at a cost of $13.4 billion annually. New spending would be roughly $400 million per year.
- "Space Force Heavy," which adds more Army and Navy units, including elements of the Missile Defense Agency. The total workforce would be approximately 48,500 people at $21.5 billion with $500 million in new funding a year.
A mix of these options, or what Harrison called a hybrid, is also possible, he said. He pointed out that any of these options would leverage a "more than 50 percent" civilian workforce.
"It would be a more civilian-heavy service than any of the others," echoing what he previously told Military.com.
Harrison still criticized the Air Force's "larger scope" estimate, which would require thousands more people and a headquarters for what he described as arbitrary reasons.
"The Air Force was either adding new activities, things that aren't being done today, which is a separate question from creating a new service," Harrison said of Air Force Secretary Heather Wilson's 14-page Space Force memo dated Sept. 14.
Wilson's estimate called for 13,000 additional personnel. Harrison said those bodies already exist in commands such as U.S. Strategic Command.
"Why not move them over?" he said.
Harrison's numbers are roughly in line with Deputy Defense Secretary Patrick Shanahan's recent estimate that the creation of a Space Force will cost in "the single-digit billions," $5 billion or less.
Yet there are many unknowns with Shanahan's assessment, given that he did not offer last week a time period for the force's creation nor what the cost estimate included. Like Harrison's assessment, intelligence agencies, such as the National Reconnaissance Office, may be left out of the mix.
"One of the golden rules in budget analysis is, never rely on budget data that is presented orally," Harrison said Monday. "That could be anywhere from $1 to $9 billion -- a pretty broad range."
He added, "Until [Shanahan has] written it down, we don't really know for sure what he meant."
Another unknown is whether Congress will approve any of the proposals that have surfaced since President Donald Trump announced his administration's intent to create an entirely separate service for space in March.
"I would say at this point it may be a coin toss whether or not this makes it through," Harrison said.
It's going to take the right legislative language to persuade the Democratic-led House to get on board with whatever budget is proposed, he said.
"And another political factor, quite frankly, is this is seen as being 'Trump's Space Force'? Or is this something that the military is getting on board with? That's going to make a big difference," Harrison said.
Editor's note: Due to an editing error, an earlier version of this story misstated Todd Harrison's original Space Force cost estimate.