Later, the probe lowered its orbit to , with a perilune of . The perilune was lowered to five days later after 33 orbits. The CSM would then raise its perilune back to the normal . On January 13 and 14, the perilune was lowered to altitude. The orbit's perilune was lowered to on 30 December 2018, 00&colon;55 UTC. As the craft approached perilune, the descent engine was started again to begin powered descent. On August 21, perilune was dropped to and on August 25 to .