What in hell? AFAIR even in the middle of the Cold War, NASA was freely collaborating with Russian scientists. So why such decision, why this is one of the first moves by US government in the topic of Ukraine and, in short, what the fuck, America?
NASA being a governmental organization (not part of the government, but financed and controlled by it) has to follow. I do not think the scientists and engineers would make this choice, but I do not think they had a choice.
The US administration desperately wants to appear strong, capable, and relevant, and to appear to be doing something. This is "doing something" at least.
Its not really "one of the first moves"; I guessed you missed the US: not sending a presidential delegation to the Paralympics, initiating two rounds of sanctions by executive order, cancelling a broad array of contacts through NATO (as well as a number of other acts through NATO), participating in reverting the G8 back to the G7, participating in the decision at OECD to stop Russia's accession process there, participating in the UNGA vote declaring Russia's actions illegal, etc.
They were arch enemies.