JOI

abbreviationStandard termAviation

An abbreviation for Jupiter orbital insertion, the critical engine burn required to enter orbit around Jupiter.

Jupiter orbital insertion is a high-stakes maneuver where an interplanetary spacecraft fires its main engine to slow down enough to be captured by Jupiter's gravity. The timing and duration must be flawless. If the burn is too short, the probe will fly past the planet into deep space, and if it is too long, it will crash into the atmosphere or enter a highly suboptimal orbit.

Heard on the job

Telemetry confirms the main engine has shut down and JOI was successful, placing the probe in a stable elliptical orbit.

Insider tip

These burns are entirely automated because the radio signal delay to Jupiter means mission control cannot intervene if something goes wrong.