[Science World] Korea Ventures into Space Exploration, Next Goal: Securing the 'Lagrange Point'

South Korea recently succeeded in developing and launching the space launch vehicle ‘Nuriho’ using purely domestic technology. Space launch vehicle technology is closely related to military technology, and technology transfer between countries is restricted, but South Korea overcame this and fully localized all the technology. The capability to develop artificial satellites has been at a high level for some time. So far, various types of scientific experiment and practical satellites have been developed independently. South Korea boasts a high level of expertise capable of developing ‘geostationary satellites’ that observe the Earth from an altitude of 36,000 km above the surface.

By applying satellite technology, it is possible to develop space probes or space observatories. Space probes are launched to uncover the secrets of new celestial bodies. The famous ‘Voyager’ spacecraft, which left the solar system, is a representative example. It embarked on a journey to explore celestial bodies outside the Earth such as the Moon and Mars and to reveal the mysteries of the universe. South Korea has also entered this field. The beginning is the Korean lunar probe ‘Danuriho’. Launched in December 2022, Danuriho was originally planned to operate for one year, but since the fuel was deemed sufficient, its lifespan was extended to a total of three years, and it is expected to continue its mission to uncover the Moon’s secrets until December 2025. Various space exploration missions are expected to continue in the future.

What other paths will South Korea take going forward? There is a need to challenge the field of ‘space observatories’. These receive various signals from space and work to uncover the secrets of the birth of the universe.

The locations of the five 'Lagrange points' around the Earth. The yellow circle in the center represents the Sun, and the purple circle orbiting around it represents the Earth. The positions of the five Lagrange points, from L1 to L5, can be identified.

As a first step, there are opinions that a space observatory should be launched at the ‘Lagrange points’. Many people commonly think of space as a ‘completely weightless environment’, but in reality, gravity acts slightly. To ‘observe’ space, it is advantageous to stay in the same place, but it cannot remain stationary and keeps moving due to the mass of various stars and planets. However, from the Earth’s perspective, there are several locations where the influence of surrounding celestial bodies is minimal, making them stable as if fixed in place. If a space observatory is placed at such a location, it will maintain the same position stably even if left alone. These locations are called ‘Lagrange points’.

There are five known Lagrange points, named L1, L2, L3, L4, and L5. Many space observatories launched by various countries have already taken positions at L1 because it is the best place to directly observe the Sun. L2 is also an excellent environment for observing deep space behind the Earth, and various space facilities are being established there. The famous ‘James Webb Space Telescope’ is also located here. L3 is positioned behind the Sun. It is so far away that it is currently considered to have almost no practical use.

The location that domestic astronomers and space scientists are currently eyeing is L4. No other country has sent a space observatory there yet, so it could become a new frontier. Hwang Jeong-ah, a senior researcher at the Korea Astronomy and Space Science Institute, said, “The planning research was completed last year, and from now on, we will begin work to verify budget feasibility over the next three years. A memorandum of understanding (MOU) with NASA is also scheduled, and we expect to complete coordination with various domestic and international partner organizations within this year.”

Space is inevitably an unknown world. Exploring the unknown is a task that humanity must undertake for its development. Moreover, Lagrange points will be important locations to consider and utilize in the distant future when creating ‘space colonies’. Securing these locations could be an important step related to a nation’s status.

Jeon Seung-min, Science and Technology Specialist Writer

This content was produced with the assistance of AI translation services.