South Korea satellite 'communicating'
South Korea says the satellite launched on Wednesday has made contact with a ground station and is sending data.
The launch was South Korea's first successful attempt to put a satellite into orbit using its own rocket.
The satellite, which collects climate data, made contact at 03:27 on Thursday (18:27 GMT on Wednesday).
The launch - which came weeks after North Korea successfully put its own satellite in orbit - had been delayed twice due to technical reasons.
President Lee Myung-bak praised what he called a "first step towards opening an era of space science in earnest".
"We should make this an opportunity to elevate national power by a notch."
The rocket, which blasted off from the Naro Space Center at 16:00 (07:00 GMT) on Wednesday, was built in partnership with Russia. Two previous launches in 2009 and 2010 had failed.
South Korea now plans to develop a fully home-made three-stage rocket.
There has been no reaction yet from North Korea, which was condemned by the UN last week for its rocket launch - seen as a banned test of missile technology.
"The North should not see it [the South Korean launch] as a threat because they too can enjoy the same transparency with regard to the programme that the rest of us have, which is a far cry from how the DPRK [North Korea] behaves," US State Department spokeswoman Victoria Nuland said.