Cite de L'Espace, Toulouse

Advantages: One of very few space museums in Europe, great exhibits
Disadvantages: Difficult to get to

Cite d'espace is on the outskirts of Toulouse. If you visit by car, the attraction itself provides plenty of parking facilities and the locality is a pleasant enough drive. Driving through Toulouse is nightmarish though so I recommend you carefully plan your route. Once you get there, it's a wonderful museum for all the family. Admittedly it's rather techy and male-orientated, but there were plenty of families and school parties there when I visited. ...
...so I got in for free! The counter staff and guides all speak English as well as French. I was shown around the Russian exhibits by a very knowledgeable English-speaking guide, went in MIR, sat in Soyuz. Certainly a rare experience for anyone. The "trip to Mars" exhibit with robots and futuristic computers etc was also very interesting. The schoolkids who were there visibly loved it. There were other more-technical exhibits of engines, re-entry ... Read review