Rep. Bill Foster joked that the New York Republican's "groundbreaking work with imaginary numbers" will be an asset to the group.
Other critics also mocked Santos for being named to two House committees despite an extensive history of lying.
"There’s nothing that we saw that would prevent us from going to Mars,” said astronaut Scott Kelly, who spent 340 days in space.
"I saw our planet change in one decade. This is nuts."
The private space race, led in large part by Elon Musk's SpaceX, is a sign of things to come.