Sen. Mark Kelly (D-AZ) blasted Elon Musk Friday, implying the SpaceX CEO was too afraid to travel into space as two other astronauts also laid into the billionaire. Kelly’s attack on Musk came after the senator’s brother defended a Danish astronaut who Musk described as “fully retarded” on social media Thursday.

Sen. Mark Kelly (D-Ariz.) and his brother, Scott Kelly, both retired astronauts, on Friday called out tech billionaire Elon Musk over his attacks on an astronaut on his social platform X.