A lot of their initial revenue came from Air Force and other military contracts to launch satellites to space. GPS satellites, spy satellites etc. E.g here's a

A lot of their initial revenue came from Air Force and other military contracts to launch satellites to space. GPS satellites, spy satellites etc. E.g here's an article from 2016 about them launching a GPS satellite for ~$90M: https://www.reuters.com/article/us-space-spacex-launch-ula-idUSKCN0XP2T2 https://www.reuters.com/article/us-space-spacex-launch-ula-i... More recently they also launch private satellites. Iirc, Facebook has plans to launch their next satellites on a SpaceX rocket (an earlier attempt failed).