(LEAD) Nuri rocket set for 5th launch to place 15 satellites into orbit

South Korea's homegrown Nuri rocket is set for its fifth launch Wednesday, carrying 15 satellites, including five that will form part of the country's first domestically launched microsatellite constellation.

The three-stage rocket is scheduled to lift off from the Naro Space Center in Goheung, about 400 kilometers south of Seoul, at 12:25 p.m., Oh Tae-seok, administrator of the Korea AeroSpace Administration (KASA), said.

Oh said the rocket is technically ready for launch, with weather and space conditions also favorable and no concerns over potential collisions with space objects, allowing the launch to proceed as scheduled.

The payload consists of five New-space Earth Observation Satellite Constellation for National Safety (NEONSAT) microsatellites and 10 CubeSats.

About four hours before liftoff, the launch team will begin filling the three-stage rocket with kerosene fuel and liquid oxygen oxidizer after completing system checks.

Nuri's first and second stages will separate about 123 and 268 seconds after liftoff, respectively, with satellite deployment beginning between 810 and 960 seconds at an altitude of around 575 kilometers.

The five NEONSATs, Nos. 2 through 6, will be deployed at intervals of 35 to 40 seconds, with Nuri's upper stage rotating by about 45 degrees between each separation to prevent collisions. The 10 CubeSats will then be deployed two at a time at 10-second intervals.

After releasing all 15 satellites, Nuri will perform a collision-avoidance maneuver and vent its remaining fuel, completing its flight about 20 minutes after liftoff. The rocket will then remain in orbit before eventually reentering Earth's atmosphere and burning up.

The Korea Aerospace Research Institute will track the flight from facilities in South Korea and Palau in the western Pacific.

The fifth flight will mark Nuri's first attempt to sequentially deploy multiple primary satellites designed to perform the same mission.

Each NEONSAT weighs less than 100 kilograms and carries an electro-optical camera capable of distinguishing objects as small as 1 meter in black-and-white images and 4 meters in color images.

The satellites will monitor the Korean Peninsula and surrounding areas for national security and disaster response.

The NEONSAT constellation will eventually consist of 10 satellites. Another five will be launched aboard Nuri's sixth flight scheduled for next year to complete the constellation.

Once fully operational, the constellation will be capable of imaging the Korean Peninsula more than three times a day and revisiting the same location within 24 hours.