First connection 40 minutes after successful launch of Nuri… On the 22nd, Daejeon Ground Station’s full-scale correspondence 2 report

Satellite posture and orientation work in progress… On the 29th, cube satellite launch started

The second launch of the Korean launch vehicle Nuri (KSLV-II) was successfully completed on the afternoon of the 21st.

The remaining task is to check whether the satellite continues to function normally and whether communication continues normally.

On the 21st, the Korea Aerospace Research Institute (KAI) analyzed the remote reception information (telemetry) of the Nuri, which contains the flight information of the launch vehicle. It started to orbit 700 km above the Earth’s surface.

Hangwooyeon operated tracking radar and telemetry antennas at the Naro Space Center and Jeju Island to track the Nuri.

Data on the late flight, including third-stage engine shutdown and satellite separation, were received from the Palau Tracking Station in the western Pacific.

After separation, the performance verification satellite started operation by the built-in automatic operation program, and it is estimated that it is currently tumbling (rotating the satellite before positioning it properly) in the aftermath of the ejection and orbiting around the earth.

The Ministry of Science and ICT (Ministry of Science and ICT) did not disclose detailed communication-related information on that day, but made it clear that the first communication between the performance verification satellite and the ground station was made.

It was predicted that the first communication with Sejong Base in Antarctica would take place in about 42 minutes after launch for 11 minutes, and connection with the anti-accidental ground station for about 1 hour and 40 minutes after launch for 6 minutes.

Since it was confirmed that the launch of the Nuri was successful as planned, it is certain that the actual communication was at a similar point in time.

Ahn Sang-il, senior researcher at the Aircraft Satellite Space Exploration System Design Department, said in an online briefing on the 10th before the second launch of the Nuri-ho, “It is important to understand the initial state, so it is necessary to select a ground station that can communicate and receive a little bit of the satellite state.” “It is possible to check at an early stage whether the satellite is in a normal state, how far it rotates, and whether the control is working as expected,” he explained.

The anti-accidental technicians work de-spin to determine the position of the satellite while determining the degree of rotation through the information sent by the satellite.

After this process, the satellite reaches the sun pointing stage.

The sun point is the point at which it is confirmed that the satellite is well positioned and orbits stably.

The time of reaching the sun point predicted by the anti-accident was 8 to 9 pm, about 4 hours after the launch.

On the other hand, the performance verification has been changed to a ‘beacon’ mode that transmits only a part of the signal from about 3 hours 57 minutes to 5:40 minutes after launch in case the battery runs out.

Beacon signal is received twice at Sejong Base in Antarctica.

Full-fledged normal communication will take place at dawn on the 22nd, about 11 hours after launch.

At this time, it continuously communicates with the satellite through the antenna of the main ground station, anti-aircraft warfare ground station, and grasps a more specific satellite state.

The Ministry of Science and ICT plans to hold a briefing around 11 am on the 22nd and announce the results of satellite communication based on the findings.

On the 7th day (29th) after the satellite has been placed in orbit, it is reported that the posture has been stabilized and the operation of ejecting (separating) four cube satellites one by one every two days begins.

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CubeSatellites are miniature satellites produced by student teams at Chosun University, KAIST, Seoul National University, and Yonsei University, respectively, and communicate through each school’s ground station.

/yunhap news