Nuriho, now competing for ‘cost-effectiveness’… Save 47% on costs by shooting 4 times a year

(Seoul = Yonhap News) Reporter Seunghan Cho = The Korean launch vehicle Nuriho succeeded in its fifth launch, taking one step closer to securing reliability and commercial use through repeated launches.

However, in order for Nuri to be competitive in the commercial launch market, the fundamental task of lowering launch costs and increasing transportation capacity remains.

First, while analysis suggests that it is more realistic to reduce production costs by increasing the number of launches rather than improving the launch vehicle by making it lighter, a plan is also being attempted to expand the transportation range to further space, such as the moon, by using the kick stage.

◇ The key to commercializing Nuri is the number of launches... Performance improvement is a long-term task

According to a paper titled ‘Korean Launch Vehicle Development Project Achievements, Limitations and Lessons’ published by Jin Seung-bo, a senior researcher at the Korea Aerospace Research Institute, in the Journal of the Korean Aerospace Society on the 11th, it was estimated that if the performance of Nuri was improved by reducing its structure, the launch cost compared to the input weight could theoretically be reduced to 60% of the current level.

On the other hand, assuming that the basic model of Nuri is launched four times a year, labor and material costs can be reduced during parallel production, and the cost per launch can be mathematically reduced to 53%.

Considering the research and development (R&D) costs involved in improving performance, increasing the number of annual launches may be more effective in reducing costs than increasing launch vehicle performance.

As the current Nuri was developed with the goal of local production and technological independence, it is difficult to say that the launch cost is low.

Currently, the launch cost of units 4 to 6 included in the Nuri upgrade project is set at 104.82 billion won per unit, including launch operation costs.

Calculating based on this, the launch cost based on the sun-synchronous orbit (SSO) at an altitude of 500 to 700 km, which commercial satellites mainly target, is 47.65 million won per kg.

This is known to be almost similar to Rocket Lab's launch service cost.

If Nuri lifts 500 kg to SSO using ride sharing, the launch cost is estimated at about 24 billion won.

As the launch cost per next-generation medium-sized satellite is currently 35 billion won, it is analyzed that it is economically feasible to transport public satellites using a domestic launch vehicle if two or more satellites can be deployed through ride sharing.

Of course, in the long term, it is expected that it will be a challenge to further increase cost-effectiveness through performance improvements such as weight reduction.

Kim Seon, vice president of space business at Hanwha Aerospace [012450], said in a briefing after the fifth launch of Nuri, "We are actively discussing with the Space Administration and Korea Aerospace Research Institute on areas where Nuri's manufacturability and mass production can be improved, costs reduced, and performance improved."

◇ Safety issue limit booster… After being eliminated from the preliminary round, take on the Kick Stage again

Apart from lowering the launch cost, measures to increase Nuri's transportation capacity itself can also be considered.

This is a method of securing additional thrust by installing an additional booster or adding a kick stage or orbital transport ship to the third stage.

Major launch vehicles, such as Europe's Ariane and Japan's H3, are equipped with solid boosters to increase thrust and transport heavier payloads.

However, the location of Naro Space Center and launch vehicle operation conditions are obstacles to installing a booster on Nuri.

If a booster is installed to improve Nuri's performance and it is launched from the Naro Space Center toward the south at an azimuth of 170 degrees, the first-stage drop point will be formed near the Okinawa Islands in Japan, 600 to 800 km away.

The second-stage debris drop point is also formed in Indonesia at a distance of 3,500 to 4,000 km, and above all, the booster drop point is formed near Jeju Island and Japan's Fukue Island, with a flight distance of 100 to 200 km, making it difficult to ensure safety.

Nuriho is also not a launch vehicle designed with the premise of being equipped with a booster, so changing its structure and operation system poses a burden.

For this reason, the method of using the kick stage, which produces additional thrust after being separated from the third stage of the Nuri, is being discussed as a realistic alternative.

This is because the payload can be sent to a higher orbit or transported to distant space, such as the moon, without significantly changing the launch vehicle itself.

Even when the Ministry of Science and ICT was in charge of the Nuriho project, there were several attempts to commercialize the method of adding a kick stage, but they failed to pass the preliminary feasibility study threshold.

The plan to reflect performance improvements in the Nuri's upgrade project in 2020 was aborted, and the plan to reflect the Nuri's kick stage in the Apophis exploration project in 2022 also failed to pass the preliminary test.

However, as the pace of space development has recently accelerated, the kickstage development project is also gaining momentum.

According to the Space Agency, Nuri can carry 3.3 tons at an altitude of 300 km, and if it carries a kickstage-based orbital transport ship, it will be able to send up to 800 kg to the moon and 40 to 50 kg to Mars.

Last May, the Space Agency announced a project to develop a kickstage-based orbital transport ship that can be loaded on the third stage of Nuriho, investing 40 billion won over four years.

According to the business plan, the orbital transport vehicle will use Nuri to enter the parking orbit and insert one satellite, and then move to the lunar transition orbit and perform the mission of inserting one additional lunar probe.