One concept Gateway may be in a polar orbit with an apolune of 70,000 km and perilune of 3,000 km. One concept is for the lander and Orion to meet at Gateway. Our alternative is for Artemis to stay in a low lunar orbit and be met there by Orion, the cargo transfer vehicle and the tanker. There are many orbit maneuver sequences that will get us from Gateway to our 15 km altitude orbit. A simple one is shown below. We first lower apogee to 3,000 km we then do a Hohmann transfer from the 3,000 km orbit to the 1753 km orbit (that is 15 km altitude). The maneuver to lower apogee is shown below.
The delta-v for the first maneuver is 0.49 km/s and for the Hohmann transfer is 0.39 km/s.
While in low lunar orbit in between landings the lunar lander will do high resolution photo surveys of the surface. These will be used to train the neural network for landing navigation.