Just FYI the army also has other tasks such as the Army Corps of Engineers who built the panama canal.

I believe two of these are naval aviators, and they would take exception with the "army" characterization.

But you're generally correct. It's very common that astronauts will not only have a military background, they frequently are active duty military officers on a long term detail to NASA.

The army is not well represented in the astronaut corps, because the US army only flies helicopters under an inter-branch coordination agreement.