I’m sorry, I’ve not heard of any that run in the UK, though I know they are popular in the US.
The best you might manage is if a local planetarium organised a special event to let children explore something of what it might be like to go into space. But it probably takes a lot of expensive equipment to do it well. There is a space-rocket simulator at London’s Science Museum that is supposed to be a great experience!
I’ve always been fascinated by space travel – when I was a teenager I won a competition in the local newspaper and the prize was to go to the Armagh Planetarium (in Northern Ireland) to meet Jim Irwin, one of the astronauts from Apollo 15: he walked on the moon. In fact, he even drove on it, since they brought an electric car with them on that trip.
If you are interested, there is a great documentary about the moon missions that you can get on DVD – it’s called “In the Shadow of the Moon’. One of my favourite recent films – really inspiring!