[Nuriho 3rd Launch] Q&A - "Ground Equipment Failure... Retry Possible Tomorrow"

O Tae-seok, 1st Vice Minister of Ministry of Science and ICT - Ko Jeong-hwan, Director General of KARI

The third launch of the Korean space launch vehicle Nuri, scheduled for 6:24 PM on the 24th, was postponed due to a ground facility malfunction. The issue is not with the vehicle itself and is relatively minor, so attention is focused on whether a re-launch can be attempted the next day.

Below is a Q&A session with O Tae-seok, the 1st Vice Minister of the Ministry of Science and ICT, and other officials.

(Vice Minister Oh's briefing)

During the removal of the valve supplying helium to the internal tank of Nuri, a communication error occurred between the launch control computer and the launch pad control computer. It was confirmed at 3 PM, and there is no problem with the valve itself, so manual operation is possible. However, there is concern that it may not operate when switched to automatic mode (10 minutes before launch), so the 6:24 PM launch is canceled. This is not a problem with the launch vehicle itself. Currently, the launch vehicle remains upright, and we plan to analyze and resolve the issue within today. Whether the launch can proceed tomorrow depends on the identification and resolution of the system issue to be conducted this evening. Considering all factors, we will hold the Launch Management Committee again (within tomorrow) to announce the possibility and timing of the launch.

- Please explain the cause of the malfunction in detail.

▲ (Koh Jung-hwan, KARI Director) After posting the launch operation procedure at 12:24 PM today and inspecting the propulsion system components, an anomaly was discovered around 3 PM. A communication error occurred between the launch control computer and the launch pad equipment control computer. Accordingly, there could be an obstacle to performing automatic procedures, so the launch was canceled. It was determined to be a communication problem between ground equipment, not hardware of the launch vehicle.

- There was no issue during yesterday’s inspection; why did it occur today?

▲ Inspections are conducted sequentially. Yesterday, after connecting the umbilical and supplying power, the leak test line connection was confirmed. Only after completing this could the inspection of the vehicle, gas, and propulsion system supply components be performed. Therefore, the issue was discovered today.

- The payload remains upright on the launch pad; when can a re-launch be possible?

▲ The satellite can only endure for a certain period. On the launch vehicle side, the ventilation system must operate 24 hours to protect the satellite, so it cannot withstand indefinitely. The re-launch timing will be informed considering weather and the possibility of collision with space objects. Today, identifying the cause and taking measures to prevent recurrence are urgent. If resolved today, a re-launch attempt could be made as early as tomorrow.

- Has this problem occurred before?

▲ The same software and equipment were used during the first and second launches, but no issues occurred.

- How long can the payloads endure?

▲ A total of eight satellites are mounted on the third stage. The main payload, the Next-generation Small Satellite 2, can endure about a week, based on confirmation. Charging is possible even while upright. Other CubeSats are believed to last longer, but this needs to be verified.

- Was there a Plan B for this situation?

▲ Numerous components can cause problems at any time. To cope with such situations, related company staff and responsible researchers are always on standby, equipped with necessary means and preparations. Work to identify the cause is already underway on site.

- Has oxidizer charging been done?

▲ It has not been done yet.

- Why do problems keep occurring? Why not move the vehicle to the assembly building like last time?

▲ Operating numerous components and software always carries the possibility of issues. This is common even in foreign launch processes. Ignoring and overlooking problems can lead to failures. It is important to address and improve them. Last time, a sensor inside the launch vehicle failed, requiring disassembly in the assembly building. This time, since the problem is between control computers, it can be handled while the vehicle remains upright.

- If the launch proceeds tomorrow, what time will it be?

▲ The launch time will remain the same at 6:24 PM. Currently, identifying the cause and making improvements is the priority.

- Please explain the cause of the malfunction and the related component in detail.

▲ The communication system operating the cryogenic helium pressure relief valve inside Nuri had a problem. (This valve) is connected to a cryogenic helium charging tank inside Nuri (at minus 180 degrees Celsius), and it supplies and releases helium to and from that tank. The problem occurred controlling a valve located in ground facilities, not the vehicle itself.