President Moon Jae-in has stressed that his administration would press ahead with space projects after South Korea's first domestically built rocket failed to fully place a dummy satellite into orbit.
The president, who watched the Thursday launch from the space center, said the rocket completed its flight sequences but failed to place the test payload into orbit.
"Unfortunately, we did not fully reach our goal," Moon said in a speech at the site.
"It's not long before we'll be able to launch it exactly into the target trajectory," he said. "The 'Korea Space Age' is approaching."
The three-stage KSLV-II Nuri rocket rose on a column of flame from its launch pad at Naro Space Center at 5 p.m. (0800 GMT). It was designed to put 1.5-ton payloads into orbit 600 to 800 km above Earth.
The failure would be a setback in the country's attempts to join the ranks of advanced space-faring nations.
"Today's launch left some disappointment, but it is significant as it was the first test of the launch vehicle independently developed with our own technology," science and technology minister Lim Hye-sook said.
This comes as the South's nuclear-armed neighbor North Korea was the most recent entrant to the club of countries with their own satellite launch capability.
Ballistic missiles and space rockets use similar technology. Pyongyang put a 300-kilogram satellite into orbit in 2012 in what Western countries condemned as a disguised missile test.
Space launches have long been a sensitive issue on the Korean peninsula, where North Korea faces sanctions over its nuclear-capable ballistic missile program.