This may be a stupid question, but why don’t we just build hadron colliders in space? No digging massive chunks of ground, and maybe scale up the existing structure instead of building a newer bigger one in the future?

I think even if they got through the hurdles of price and getting everything up there into a stable orbit. There will be way too much added variables if it was in space.

The whole idea of the collider is for the intended particles to collide. CERN and others go to great lengths to ensure that their collider is shielded so no external particles can enter. Earth atmosphere actually does a pretty good job at absorbing and reflecting/deflecting some of these particles.

I can imagine that if the collider were in space, the added exposure to particles and cosmic rays etc. would be detrimental to its stability.