>But still, once they started taking foreign citizens with them, I would have thought that Britain would be among the first on that list. Between 1984 and 1985 there were a Canadian, a Saudi, someone from the Netherlands and a Mexican, and then there was a long pause until 1992, presumably because of the Challenger disaster.

Without the loss of Challenger, a Briton would have flown in space on the shuttle in the 1980s. <https://en.wikipedia.org/wiki/Zircon_(satellite)>