In the 1990s, Roykirk joined the team which designed and created the DY-100 class ship along with Jeffrey Carlson, Shannon O'Donnel, Walter Nichols and Shaun Christopher. Roykirk designed the sleeper ship’s automated computer system. (ST - The Eugenics Wars novel: The Rise and Fall of Khan Noonien Singh, Volume 2)
In the 1990s of an alternate timeline, Christopher considered Roykirk a mentor. While Khan Noonien Singh and his Augments attacked Paris and London, Wilson Evergreen brought Roykirk together in Nevada along with Andrei Novakovich and other geniuses to build three DY-100 spacecraft, one of which was piloted by Christopher. (DS9 - Myriad Universes novel: Seeds of Dissent)
In 2002, Roykirk launched the Nomad space probe, Earth’s first interstellar probe with the mission to seek out new life. Roykirk's ambition was to build a perfect thinking machine capable of independent logic. (TOS episode: "The Changeling", Last Unicorn RPG module: All Our Yesterdays: The Time Travel Sourcebook)
In 2267, after colliding with a meteor, drifting in a damaged state and then merging with an alien probe, Nomad destroyed the Malurian system and fired on the USS Enterprise. It heard Captain James T. Kirk’s hail and, thinking Kirk was Roykirk, ceased fire. Kirk later confessed that he was not Roykirk, prompting the device to reconsider sterilizing the starship. (TOS episode: "The Changeling")
- TOS episode: "The Changeling"
- TOS reference: Spaceflight Chronology
- DS9 - Myriad Universes novel: Seeds of Dissent