Well there was America's Army[1], a video developed for the US Army. There are a whole series of these games and if they are not propaganda I don't know what is.

[1] https://en.wikipedia.org/wiki/America%27s_Army

I'm not asking if the US army has ever produced propaganda. I'm asking if everything it produces is propaganda.

Propaganda can have a rather neutral definition. US Army ads are definitely propaganda. NASA posters are more of a form of marketing and self promotion. I don't think I've ever seen an agricultural statistics leaflet. But if you go to a public health clinic, you will see lots of propaganda about smoking, well care visits for infants, vaccines, STDs, etc. There is tons of propaganda in the US, much of it put out by 3rd parties, for example anything to promote "awareness" of some cause or issue. Also, any issue-oriented documentary is probably propaganda.

Is it propaganda because of who pays for it? If I had paid to produce and distribute the leaflet that public health clinics do, would that be not-propaganda just because it's not state-produced?

Let's see what the dictionary has to say:

https://www.merriam-webster.com/dictionary/propaganda

1 capitalized : a congregation of the Roman curia having jurisdiction over missionary territories and related institutions

2 : the spreading of ideas, information, or rumor for the purpose of helping or injuring an institution, a cause, or a person

3 : ideas, facts, or allegations spread deliberately to further one's cause or to damage an opposing cause also : a public action having such an effect

so.. quite a few things are propaganda.

it's not really so scary a term, and so being not so scary, we can see it more clearly and not be afraid of labeling it.

the question is more "is this good propaganda or bad propganda?"

It's neither. It's space-agency marketing.

soo, you're saying it's "the spreading of ideas, information, or rumor for the purpose of helping an institution"?

Exactly, just like these propaganda posters:

https://www.jpl.nasa.gov/visions-of-the-future/

I think I mentioned nonstate producers of propaganda, calling them third party