The launch of the nation's ocean weather-communications satellite, Chollian, has been delayed a second time.

The Ariane 5 rocket, which is carrying the satellite, was to lift off Thursday at 6:41 a.m., Korea time, at the Guiana Space Center in Kourou, French Guiana, but the countdown was stopped at 17 seconds prior to launch. The launch was suspended after pressure in the rocket’s first phase and upper sections suddenly dropped.

Chollian is a multifunctional observation satellite that will provide communications, maritime and climate data from geostationary orbit. It will remain in orbit for the next seven years at an altitude of 36-thousand kilometers.

It is unclear if the launch will occur on Friday.