For example en the Moon landing example, I guess NASA will make press release, but it looks impossible to automate reading it and deciding. (What if the starship colides with the Moon? What if they can't return? What if it explodes 5 seconds after landing? What if it's a joint NASA+ESA project?)
Generally, event contracts are legal contracts technically. We have a team that spent a ton of time developing templates to incorporate all types of events (hard problem). Here's an example definition: https://kalshi-public-docs.s3.amazonaws.com/regulatory/ruleb...
This is hand-waving a bit, and not only doesn't address the OP's question (does a fatal collision count,) but is a good example of the ambiguities that could plague any "simple" contract.
I would think for ultimate compliance that Kalshi would be the first order-judges, but if the parties disagreed, these ultimately get decided upon by an actual Judge giving a good-faith determination of the question with a reasonable persons' definition of the terms.