I remember reading that this spacecraft would not have been launched without a Russian rocket engine, and that the plutonium fuel also came from that country.
"Owing" something is not always about money. "The West" owes a large part of its wealth to Africa and Asia. It's a team effort, not just a business transaction.
True, but I meant a particular subset of "owing" in which you consider which parties are directly responsible for some event. Paid out vendors are usually not considered the primary parties.