Would this be a good activity for 2 adults with no children, or is this only fun if you have kids to bring?

Its a nice visit for adults to enjoy too. Lots of history.

Yes, there is plenty for adults to enjoy at RMSC (and families with kids). There are many exhibits, activities and events for all ages year-round. They even have "Adults Only" events on weekend evenings, like Adult Summer Camp, every few months. We had fun at the summer camp event. My partner and I don't have kids at this time, and we love going to RMSC.

BlueCollar Millennial is right! I'd particularly recommend checking out the current featured exhibition SoundSense, exploring sound and music, and an Electricity Theater show, included in museum admission (4pm on Tues and Thurs and 12, 2 and 4pm on weekends).

If you're a child at heart, and genuinely like science (or history) I enjoyed myself with no children.