The space agency has published its budget request to Congress which would see funding for science projects cut by nearly a half.

The worried reaction within space and national security agencies highlights the risks of government’s exclusive dependence on SpaceX for crucial tasks, including classified missions.

Why it matters: Musk's rift with President Trump exposes how reliant NASA has become on a single private sector partner to reach the International Space Station after ending the space shuttle program in 2011. Musk eventually walked back the threat Thursday, but it demonstrates how critical SpaceX is to the American space program.