SpaceX CEO Elon Musk took to Twitter on Thursday to criticize his company’s biggest U.S. rocket-building competitor United Launch Alliance.
“Because their rockets are not reusable, it will become obvious over time that ULA is a complete waste of taxpayer money,” Musk said.
Musk’s comment is the first made by SpaceX leadership after the U.S. Air Force on Friday awarded his company and ULA with billions worth of national security launch contracts.