WASHINGTON — The fate of President Trump’s plan to stand up a Space Force lies with Congress. Like other lawmakers, Sen. Joni Ernst (R-Iowa), a member of the Senate Armed Services Committee, said on Thursday that she is “open to a debate.”

During a Heritage Foundation media roundtable on Capitol Hill, Ernst said it remains a wide open question for her committee whether a Space Force should be a “separate stand-alone force or if it can be better maximized as part of the existing Air Force.”

“I think we need to keep an open mind and figure out what really makes the most sense, and where can we leverage those dollars,” she said.

Ernst is a proponent of a strong military and she believes the Pentagon should put more emphasis on protecting satellites. “It’s is one of the last bastions that we need to address which is space, and the potential of adversaries to degrade our satellites.”

But Ernst also is a fiscal conservative and suggested she would want to understand how different options for standing up a Space Force affect the total cost.

Air Force Secretary Heather Wilson wrote a proposal for how to organize a Space Force and a U.S. Space Command, with a price tag of $13 billion over five years. Defense Secretary Jim Mattis has said the Pentagon is working on its own cost estimates in preparation for the 2020 budget submission.

Wilson’s numbers have been criticized by Space Force advocates like House Armed Services Committee Strategic Forces Subcommittee Chairman Rep. Mike Rogers (R-Ala.) who last week described Wilson’s proposal as an attempt to “gold-plate” the Space Force to make it unpalatable to lawmakers.

One of the most pointed critiques came from Todd Harrison, defense budget analyst and senior fellow at the Center for Strategic and International Studies. He said Wilson inflated the cost by adding thousands of extra personnel that would not be needed and by budgeting a billion dollars for a questionable Space Command facility.

Speaking at the Heritage Foundation on Thursday, Harrison said the “vast majority of the cost of the Space Force we already have in the budget, we already have space forces in the Air Force, Army, Navy and intelligence agencies.” The infrastructure and bases already exist as well, he said.

“You would need to add a headquarters and a layer of overhead,” which would cost about $2.5 billion to $3 billion over five years. Harrison drew a comparison with the Coast Guard, which has about 50,000 personnel. The Space Force would be about the same size, counting both military and civilians. “That’s pretty close to what we have in space forces spread across the services and the intelligence community.” The Coast Guard headquarters is about 2,600 people, or about 5 percent of the total workforce. “That seems pretty reasonable.”

One of the concerns on Capitol Hill, besides the cost, is that the administration is pushing this reorganization too hard and too fast, some experts argue.

“For supporters of the Space Force, it is easy to claim a low or neutral budget with the Space Force just using existing personnel and facilities to continue current operations plus a small overhead staff,” Kaitlyn Johnson, a research associate at the Center for Strategic and International Studies, wrote in a CSIS op-ed. “However, this also assumes that the Space Force will be able to acquire all space personnel from the other services. … With the rushed timeframe of 2020, identifying, incentivizing, and building a relationship with key space personnel in all the departments—not just the Air Force—will take time and trust. Service members will be hard-pressed to leave their service for a new department without sufficient trust in the leaders and mission of the Space Force.”

Johnson said the Pentagon should take the reorganization one step at a time. The standup of a combatant command — U.S. Space Command — will “solve many of the issues agreed upon by space experts” such as the need to strengthen space war fighting skills. “Establishing a Department of the Space Force by 2020 is rushing into an end solution without proper consideration,” she said. “If creating a Space Force is a matter of inevitability, as many believe, the process should be done thoughtfully and with intention. … An incremental approach to developing a comprehensive organization for our national security space enterprise is a smarter decision.”

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...