President Trump’s new Space Force military service would cost up to about $2.7 billion in new spending over five years, significantly less than a recent $13 billion Pentagon estimate, according to a new analysis by the Center for Strategic and International Studies.

The vast majority of troops and costs — about 96 percent — would come from existing Pentagon spending on space missions. So the new funding needed is relatively small, especially compared to other expenses such as F-35 fighter aircraft and a first-ever financial audit of the military this year, said Todd Harrison, the CSIS defense budget analyst who conducted the study.