Wearing a black leather coat, a grinning Kim was seen waving at the uniformed workers, all of whom appeared to be enthusiastically cheering him and Ju Ae.
State media released images of Kim enjoying a reception with National Aerospace Technology Administration (NATA) workers, top military and political officials, his daughter and his wife, Ri Sol Ju.
Kim’s family members and other reception attendees were seen wearing matching T-shirts that said “NATA” in English.
All of the attendees “enthusiastically cheered expressing thanks to the great father who finally ensured the successful launch”, KCNA said.
Kim showed “such paternal love for the space scientists”, the state mouthpiece added.
After Tuesday’s launch, South Korea partially suspended a five-year-old military accord with the North and deployed “surveillance and reconnaissance assets” to the border.
Pyongyang responded by calling Seoul’s moves “reckless” and saying it would also suspend the deal in full, adding that it “will never be bound” by the agreement again.
Experts have said that putting a working spy satellite into orbit would improve North Korea’s intelligence-gathering capabilities, particularly over South Korea, and provide crucial data in any military conflict.