how long was dr grace in a coma project hail mary

Dr. Grace was in a coma for the entire interstellar trip to Tau Ceti — about 13 years in the story.

Quick context

The other astronauts were also put into comas for that same 13-year journey, but Grace is the one who wakes up early after the ship’s problems begin.

Why it matters

That long coma is a major part of the plot, because it helps explain why he wakes with memory loss and has to piece together what mission he’s on.

TL;DR

In Project Hail Mary , Grace’s coma lasts roughly 13 years during the voyage.