Arguably no. While some things haven’t yet been achieved with our current knowledge we can’t be certain these things aren’t possible somehow. The weakness of humanity is that we cannot truly comprehend things we haven’t perceived in some way. However It could be argued it is either impossible for something to be impossible, or if not, maybe there is something that is in fact impossible, we can’t determine that with full certainty.
Flying is definitely impossible. It will always be impossible to someone. For example, it is impossible for dead people to fly. However, it is not hard that the impossible is made possible by one who is not restricted by such boundaries that mankind is restricted by.
But this is inductive reasoning. Just because something hasn’t been possible so far, there’s no saying with 100% certainty that it couldn’t suddenly be possible tomorrow. What if a dead person suddenly just flew, sure you could argue they’re not consciously making the decision to do so, but then this would call for us to define flying as consciously opting to fly in order to make your statement correct. It’s true that it would be impossible for a dead person to not have died (as in order to be dead, by definition, one’s life must have ended) as even with some sort of time-travel interference which stopped this person from dying, they would then no longer be dead. You could also go into that “I think, therefore I am” stuff that questions reality and whether we are being deceived into believing false things. Philosophy is just a lot. 😬 I’m sorry for this, it probably makes no sense. It’s late and Christmas and I’ve had a stressful day.