From Halopedia, the Halo wiki
Lieutenant Jet is a human commissioned officer of the UNSC Navy who serves aboard UNSC Infinity. On October 28, 2558, while Infinity was at Earth, a Forerunner Guardian under the control of Cortana arrived to subjugate the planet. Captain Thomas Lasky ordered Lieutenant Jet to plot an emergency slipstream space jump to escape, and to follow it up with more random jumps.
List of appearances