It's not a requirement that I be on every space flight. It's a fallacy to suggest that in order for something to be true, it has to be personally experienced by the debater.
That's a shame, because the entire FE argument is that none of us have been into space, therefore it isn't possible. Sadly nobody else on here has been in my house, damn - that must meen it doesn't exist! Wait, does that also mean I don't exist, since nobody on here has met me - OMG! The weakness and continous failure of FE is causing a rift in space-time continuum.
I can, however, interact with you, by the means of this board.
I type something, you respond to it and then I respond again.
Due to this, I have a working hypothesis that you are a sentient being of some sort. By my own experience, you have a domicile of some sort. Most earth based sentient beings call that domicile a house or home.
Therefore, in the absence of any other data, I can assume that you exist and have a house.
Now, I cannot, by the experience that I have had with you at this point, prove if you are male, female, nor can I prove your race, shape or eye colour, but you are a being.