The Naro space rocket has blasted off after a day’s delay at the Naro Space Center on the south coast.

The nation’s first space rocket was launched as scheduled at 5:01 p.m. on Thursday. The rocket, KSLV-1, successfully reached the speed of sound 50 seconds after blastoff, but communication with the rocket was lost after 137 seconds at an altitude of about 70 kilometers.

President of the Korea Aerospace Research Institute Lee Joo-jin said in a briefing that all data shows that everything was functioning normally before the loss of communication, and that his institute will do everything it can to reestablish the communications link.

It's not known whether satellite fairings, the first-stage booster, and a satellite aboard the rocket were successfully separated.

The Naro rocket, manufactured in cooperation with Russia, was launched with an aim of putting a science satellite into orbit some 300 kilometers above the earth.

Scientists at the space center say that whether the satellite is successfully put into orbit will be determined about an hour after the blastoff.

The launch had previously been aborted on Wednesday due to a malfunction of fire extinguishing equipment.

The first attempt to put the satellite into orbit aboard the Naro space rocket failed last August due to the malfunctioning of a fairing that covers the satellite.