You will , for a landing , start from orbit , so you have altitude to give , and want a negative altitude change You can deal with that using more efficient Hohmann Transfers . Before landing , your orbit should be the lowest it can be while still missing terrain . To that end , yes the very final phase of flight may have a few hundred meters of altitude to reduce before landing depending on terrain , but you can take that into account and hybridize the maneuver far closer to the ideal case than a zerolift maneuver . A zero lift maneuver loses altitude constantly meaning you simply cannot be ' as low as possible while still missing terrain ' and then lose altitude throughout the entire maneuver . A constant altitude or controlled altitude landing is still going to be more efficient , as a result .