The Cosmosphere's got a more impressive collection (though that Saturn V makes up a lot of ground for Huntsville) and the presentation is much better.
There's an OK zoo (great, adjusting for where it is, really) nearby, worth a stop if you're there with kids anyway, but not much else I know of in the area. It's weird that there's such a good museum so far from everything, including from the most-traveled highway through-routes for the state.
Neil Armstrong’s Museum in Wapakoneta, OH isn’t that much further away, but much smaller.
I'd also been to the Cosmosphere as a kid (the SR-71 in the lobby is how I recognized that one when I returned, haha, don't see that every day) and have been about three more times over the last 15 years, as an adult, and it's still great.
They have, IIRC, one of the Gemini capsules, but also some really cool demonstrations. It is worth it to time that and one of the Trinity test site tours if you're interested in nuclear history as well, then take a trip north to Albuquerque for the Nat'l Nuclear History Museum and (for the kids and kidlike adults) Explora is a neat little hands on museum.
It was built near the most-traveled highway through-route in Kansas, considering it was originally established in 1962.
It's only a couple of miles from US-50. Much of US-50 aligns with the first transcontinental highway, the Lincoln Highway; and for much of the 20th century US-50 was one of the primary east-west highways. It looks like it currently skirts around Hutchinson, but I'd bet 50 years ago it passed directly through the middle of town, very close if not adjacent to the Cosmosphere.[1]
The construction of I-70 in Kansas started in the mid 1950s, but didn't completely cross Kansas until 1970. And it would have taken decades for development patterns to shift from the US-50 corridor to the I-70 corridor.
[1] At least as of 1939 it appears to pass directly through the downtown: https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~2... (EDIT: 1962 map shows the same: https://www.ksdot.gov/home/showpublisheddocument/4727/638724...)