One of the biggest tourist attractions is the Technik-Museum, also because they know how to bring new exhibits with big media coverage to Speyer. For example the Russian space shuttle Buran ("blizzard") was shipped upwards the Rhine River, and the closer it came the more media hype was created. In Speyer itself on the last leg the streets were crowded with people to witness the transport into the museum.On the Ascension Day weekend in 2023 there was another spectacular transport, the U-Boat U17 was hauled from the natural harbour in Speyer to the museum. It was watched by lots of spectators, according to the museaum there were a lot more people along the route. There is a report in German from the SWR with some videos here (external link).
In the meantime the Buran got its own hall which is dedicated for space travel.