From Wiki:
CAPSTONE will use a ballistic transfer to the Moon instead of a more conventional direct Hohmann transfer.[15] While trajectories of this type take much longer to reach their destination (about four months in this case, compared to about three days using a traditional direct transfer) they significantly reduce the propulsion requirements, which can increase the delivered mass (of the order of 10-15% more mass).[16] After being ejected from Earth orbit by a series of burns of the Photon stage, the spacecraft will reach a distance of about 1.5 million kilometers, where perturbations from the Sun become important.[15] It will then fall back towards the Earth, intercepting the Moon’s orbit and finally entering the intended NRHO around the Moon on 13 November 2022.
Interesting stuff, thanks.