That's a tricky question! NASA uses many different types of rockets, and their heights vary drastically.

To give you an idea:

* The Space Launch System (SLS), which is the most powerful rocket NASA has ever built, stands at a whopping 322 feet tall (about the height of a 30-story building).

* The Falcon 9, a reusable rocket developed by SpaceX, is about 229 feet tall.

* The Atlas V, a rocket often used for commercial and government missions, is around 190 feet tall.

So, there is no single answer to how tall a NASA rocket is. It depends on the specific rocket you're asking about!