Human stationed with the initial Atlantis expedition from Earth. He was assigned to fly Rodney McKay and Peter Grodin to the Ancient satellite via Puddle Jumper, just prior to the second siege of Atlantis. Miller docked with the satellite and joined the scientists inside once gravity had been initialized.
When it was discovered that rerouting power in the satellite could only be achieved by E.V.A., Miller flew Dr. McKay to the desired location. He and Rodney soon witnessed the Ancient satellite do its job by destroying one of the three Wraith hive ships en route to Atlantis, but was also forced to watch as the remaining vessels annihilated the satellite -- with Dr. Grodin inside.
Miller either possesses the Ancient gene or was given gene therapy by Carson Beckett.
The Siege, Part 1 - Miller pilots a Puddle Jumper to the Ancient satellite, 15 hours away from Atlantis, so that the platform may be used to defend the city from a Wraith slaughter.
Reunion - Lt. Miller pilots Jumper One, delivering Carter, Ronon, Zelenka, and a pair of Marines on a mission to save Sheppard's team inside a Wraith laboratory.