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.
The World in Shock. On October 4, 1957, the Soviet Union launched the world's first artificial satellite, Sputnik 1. The name comes from a Russian word for traveling companion of the world.. It was a smallish metal ball that weighed just 83 kg (184 lbs.), and was lofted into space by an R7 rocket.