Astronaut Wears diapers

Lawyers are bound to quibble with the details of courtroom scenes. Same goes for teachers watching films set in the classroom. And it even extends to astronauts viewing movies that simulate space.

While Neil deGrasse Tyson has taken apart the science of movies like Gravity and Interstellar, NASA astronaut Tracy Caldwell Dyson has a much simpler bone to pick with Hollywood’s version of space travel.

According to Dyson, a consultant on the new Ridley Scott-directed sci-fi thriller The Martian, most movie astronauts looked pretty comfortably dressed underneath their space suits. “But they should be wearing… maximum absorbency garments, or MAGs for short, ” she told Yahoo Movies, which you can watch in the video above. “You know them as diapers. And they’re a reality in space travel. And some movies omit this very important garment.”

Related: ‘The Martian’ Cast (and One Real-Life Astronaut) All Pretty Much Agree Aliens Look Like E.T.

Jessica Chastain, whom Dyson tutored for her role as NASA mission commander Melissa Lewis, offered a solid explanation for why most astronaut films (including The Martian) commit this wardrobe snafu: “We don’t want to see Matt Damon in a diaper.”

Considering that The Martian (based on the popular novel by Andy Weir) finds Damon as an astronaut who wakes up from an accident to find out he’s been abandoned by his crew and is now stranded on Mars, diapers would probably come in handy.