There are two types of American citizens. Natural born citizens are born on US soil, regardless of citizenship of either parent or to a parent who is a US citizen temporarily living abroad as a US citizen. Naturalized citizens are not born on US soil, but later become citizens through process. Ted Cruz' mom was a US citizen, simply visiting Canada on a work visa. This meant that Cruz did NOT have to go through the naturalization process, and could claim immediate US citizenship. His mom never became a Canadian, his dad was a Cuban. Ted is a natural born citizen under the law, despite being born in Alberta to an American citizen. If his American mom would have been visiting space when he was born, as long as she was an American at the time, and not a citizen of Mars, he's good to go.
Hope this helps.