Here is a very interesting philately letter with cachet and from the information I could find on the internet this international exhibition was held in Lucerne Switzerland in 1981. On stamps.org it was
told that the “ cachet designers in the Soviet Union added the Columbia space shuttle by mistake and within days this was pulled out in the Soviet Union”
This letter is from 1981 but
it was used in 1992 after the fall of the Soviet Union so it is interesting.
Maybe someone had it stored and used it in 1992 or the post office had it stored away, let me know if you have any information.
Then on the wiki I found some information on the Soviet Buran shuttle program. This was developed because there was concern in the Soviet Union on the US space programs in the 1980s. The only orbital launch with The Buran was in 1988.
From history we know the story with the Swiss Army Knives used on the space missions and if you search on the internet you will find information.