They can go in incubator now. They can be put in incubator 2 days after set or up to 8 days. The duck egg that was layed yesterday can be but wait a day or 2 for the newer ones. I would wait a while until you have a clutch of eggs that are needed, the eggs will be fine up to 8 days.
At last, on January 31, 1958, the United States succeeded in launching its first satellite, the Explorer. The Explorer was still slighter than Sputnik, but its launch sent it deeper into space. The Soviets responded with yet another launch, and the space race continued.
A Brief History of the Discovery of Cosmic Gamma-Ray Bursts. In October of 1963 the US Air Force launched the first in a series of satellites inspired by a recently signed nuclear test ban treaty. Signatories of this treaty agreed not to test nuclear devices in the atmosphere or in space.