South Korea was planning to launch a prototype orbiter to the moon in December 2020.
But the ministry of science announced a postponement, to July 2022.
The delay was necessary as engineers found the orbiter, in its current design, would end up weighing about 130 kilograms more than they originally planned.
The committee in charge decided to adjust the spacecraft's orbit to save fuel.
When it gets to the moon, instead of a one-year circular orbit, it'll do nine months in an elipse and three months in a circle.
A longer design period means an extra cost of about 13 million U.S. dollars.
This is the second time the Moon administration has delayed the launch.