[Q&A] "Praying earnestly... Success if 700km orbit satellite is launched" [Nuriho 2nd Launch]

O Tae-seok, 1st Vice Minister of the Ministry of Science and ICT

[Asia Economy Reporter Kim Bong-su] South Korea's first indigenous space launch vehicle, Nuriho's second launch, is scheduled to take place precisely at 4:00 PM on the 21st as planned.

The Ministry of Science and ICT and the Korea Aerospace Research Institute (KARI) announced this at a press conference held at 2:30 PM in the briefing room of the Naro Space Center in Goheung-gun, Jeollanam-do. Earlier, the Launch Management Committee, chaired by First Vice Minister Oh Tae-seok of the Ministry of Science and ICT, held a meeting from 2:00 PM to review the final inspection results of Nuriho and various conditions including weather, concluding to proceed with the launch as scheduled. Nuriho was transported and erected on the second launch pad from the assembly building 1.8 km away early the previous day and secured. Following the decision of the Launch Management Committee this morning, oxidizer and fuel loading was approved and is currently underway.

The weather is currently very favorable. Around the Naro Space Center, ground winds of 3 to 4 m/s and upper-level winds of about 15 m/s are blowing, with no possibility of lightning or rain. As of 2:30 PM, Nuriho has completed fuel loading and plans to finish oxidizer loading by around 3:10 PM. From 3:50 PM, the automatic operation system will be activated under computer control to begin the countdown. If launched at 4:00 PM, it will enter a 700 km orbit about 897 seconds later, separating the performance verification satellite first, followed by the satellite mock-up 70 seconds later. Completion of this marks a "successful launch." The Ministry of Science and ICT and KARI will analyze data for about 30 minutes afterward and make a final announcement on the success of the launch around 5:10 PM.

Vice Minister Oh said, "The Ministry of Science and ICT and KARI will do their utmost to prepare for the second flight performance test and successful verification of Nuriho," adding, "We pray that the launch proceeds without any issues."

Below is a Q&A with Vice Minister Oh:

- What is the criterion for judging the success of the second launch?

△ This is the second test launch. Two launches are conducted during the development of the Nuriho launch vehicle. The main focus of this second launch is whether Nuriho can carry a 1.5-ton payload to the target 700 km orbit at a speed of 7.5 km/s, placing the performance verification satellite and mock-up there. Additionally, since it carries a performance verification satellite weighing about 162 kg, verifying its performance is important, and it is also necessary to check whether the CubeSats operate properly. Whether the performance verification satellite is properly positioned and functioning normally can be confirmed the next day through communication with the Daejeon ground station. The CubeSats will require about a week before ground communication can confirm their normal operation.

- What variables remain?

△ During the first launch, a valve issue was discovered during morning inspections. Oxidizer and fuel loading are currently in progress. Fuel loading was completed around 2:27 PM, and oxidizer loading is ongoing, expected to finish by about 3:10 PM. No problems are anticipated during preparation. Automatic operation will begin at 3:50 PM, 10 minutes before launch, but no one knows if any issues will arise. We just pray the launch proceeds without problems.

- What is the difference between communication with the Antarctic King Sejong Station 42 minutes after launch and communication with the Daejeon ground station tomorrow?

△ About 42 minutes after launch, there will be an 11-minute initial connection with the Antarctic King Sejong Station, during which GPS information from the satellite is received. This allows us to determine whether the satellite is following the planned trajectory. The satellite's unique ID, or beacon reception, will be confirmed 4 to 5 hours later during communication with the King Sejong Station. Whether the satellite is functioning properly will be confirmed around 10 AM tomorrow during communication with the Daejeon ground station, 18 hours after launch. Telemetry information installed on Nuriho's third stage will be received to verify whether separation occurred at the correct altitude and speed.

- Must both the performance verification satellite and the satellite mock-up successfully separate at 700 km altitude?

△ There is no clear standard. The goal is to reach 700 km altitude 14 minutes and 57 seconds after launch, with the performance verification satellite separating first, followed by the satellite mock-up one minute later. It is expected that once the performance verification satellite separates, the satellite mock-up will also separate.

- You mentioned a 30% success probability during the first launch; what about this time?

△ The situation is similar. However, since this is the second time, we have conducted more thorough inspections.