The trajectory Belbruno and Miller developed for Hiten used Weak Stability Boundary Theory and required only a small perturbation to the elliptical swing-by orbit, sufficiently small to be achievable by the spacecraft's thrusters.[8] This course would result in the probe being captured into temporary lunar orbit using zero delta-v (called a ballistic transfer), but required five months instead of the usual three days for a Hohmann transfer orbit.[9] This was the first time a satellite had used low-energy transfer to transfer to a Moon orbit.[3] On October 2, 1991, Hiten was captured temporarily into lunar orbit.