The Commercial Resupply and Commercial Crew programs were intended to help develop unmanned and manned flight capability to the ISS, but they were contingent on a) demonstrating the technical capabilities to deliver and b) actually delivering. (Commercial Crew has become a gigantic money sink for Boeing, because unlike SpaceX the Starliner is many, many years late and the contract doesn't pay a cent more for delays/overruns.)

contracts = "government is a customer." the government wants a job done and you (the contractor) are paid to do it.

grants depend. grants can be "government wants someone to develop a technology/engineering capability and is paying you to do it if you can show that you're the best candidate". definitely a subsidy but not necessarily a handout.

There's a public subsidy tracker