> cruising on no power other than what the Ariane initially gave it Webb has already done multiple burns to get to L2 after being released from the Ariane uppe

> cruising on no power other than what the Ariane initially gave it Webb has already done multiple burns to get to L2 after being released from the Ariane upper stage. Preserving time on orbit is important but the bigger issue is that Webb can only fire its thrusters in one direction (because it can't point the optics at the sun) so any overshoot is catastrophic. Ariane thus was set to intentionally undershoot L2 and Webb is making up the difference with its fuel.