They didn't tell us, but we can make some guesses.
I think we can assume it extended at least into Earth orbit. At any given time in the early 21st century, there's a decent chance of a handful of humans already being in Earth orbit. Even if they got unlucky with the timing, it wouldn't be that hard to push up an upcoming mission to send someone up and see. So, the fact that we didn't hear them mentioning that astronauts are unaffected implies that they probably did the tests, and the Miracle goes that far.
But we can't assume much more than that. Humans beyond Earth orbit are pretty rare so far in our history, and it takes years to organize a special mission. Even something as simple as shooting a category one and some monitoring equipment into deep space would likely have taken so long that the Miracle would be over before they pulled it off. I'm sure someone was planning it, but didn't get it done in time, so nobody will ever know how far the Miracle extended.