From Halopedia, the Halo wiki
Halo Legends Martin O'Donnell and Michael Salvitori Halo Universe Halo: Reach, Halo Wars, Halo: CE, Halo: CE Anniversary, Halo 2, Halo 3: ODST, Halo 3 and soon to be the new Reclaimer Trilogy. Gameinformer
When John climbs the Dawn's aft cargo section, and finally rests as the Ark is destroyed behind him. Then soon after, crawling into the stasis pod within the medical bay section and simply answering all of Cortana's questions and statements by replying: "Wake me, when you need me".