President Trump continues to push for the creation of a Space Force, a new U.S. military branch focused on protecting American interests in space. Legislation creating the Space Force will likely be included in the next defense budget and a proposal may be ready by October 15.

Until then, the big question is how much it will cost. One of the few official cost estimates is found in a September 14 memo by Air Force Secretary Heather Wilson. The Space Force, it says, “will cost more than $3 billion in its first year and an additional $10 billion over the four following years.”