There is a passage from Babylon's Ashes, the sixth novel in James S.A. Corey's The Expanse series, which references a ship called "Mark Watney" (bold emphasis mine, italic author's):
In the middle column, the colony ships she and her fleet had taken: the Bedyadat Jadida, out of Luna. The John Galt and the Mark Watney, out of Mars.
- Chapter 15: Pa
Mark Watney is an astronaut from Andy Weir's The Martian, the first astronaut sent to Mars to almost die on it, as well as the first person ever to grow potatoes on another celestial body. In your face, Neil Armstrong!
Does that imply that The Expanse and The Martian take place in the same universe?