Research Information

Development of infrastructure to simulate extreme construction environments, and core technologies for construction at a technology readiness level of TRL 6
  • Date2020-03-26
  • Hit418

Development of infrastructure to simulate extreme construction environments, and core technologies for construction at a technology readiness level of TRL 6

This research aims to develop core construction technologies that can be applied in extreme outer-space environments, strategically preempting a global space development paradigm shift toward extraterrestrial settlement construction and resource development. The KICT is developing original and basic technologies for the simulation of extraterrestrial surface environments and the utilization of materials, as well as original technologies for planetary topographic and geological surveys. Specifically, there are four core technology development objectives: the development and validation of a large-scale chamber for the simulation of planetary surface environments; infrastructure construction technologies using locally available planetary materials; technology for the informatization of planetary surface construction spaces, and; the development of planetary geological survey equipment and planetary subsurface informatization technologies.



      Development and validation of a large-scale chamber for the simulationof planetary surface environments

      The large-scale DTVC (Dusty Thermal Vacuum Chamber), which simulates the extreme lunar surface environment, is used to test various technologies and equipment developed for lunar exploration, minimizing the risk of failure in actual space environments. The DTVC was fabricated in 2017, and was installed in the KICT’s Future Technology and Convergence Research Building; the DTVC was put into operation in 2019 after completing stabilization testing. The DTVC has acapacity of 50m3, and can simulate a range of lunar surface temperatures (-190 ℃ to +150 ℃) and vacuum conditions (10-7 Mbar-7mbar not including ground; 10-4Mbar-4mbar including ground). Inside the chamber is a large amount of artificial lunar regolith used to assess the impact of space dust (etc.) on the technologies and devices being tested (Figure1).

      Achieving the targetted vacuum degrees with artificial lunar regolith present in the chamber required the implementation of technology that could create a vacuum environment without disturbing the ground. Ground disturbances are caused by pressure differentials between the top and bottom of the ground, and the dust scattered by these disturbances may flow into the vacuum pumps and gages, causing system failure. Technologies were developed to simulate ground disturbances, and the accuracy of the simulation results was verified through comparisons with actual measurements. Through these efforts, researchers were able to successfully develop a technology that could be used to create a vacuum without ground disturbances; this was achieved by minimizing the amount of dust scattered and controlling decompression speed (Figure 2).

      Further,to simulate the extreme low temperatures (-190 ℃) of the lunar environment within the DTVC, a thermal flow analysis was conducted to examine shroud cooling performance and to fabricate a new shroud based on the analysis results. The system was engineered to feed liquid nitrogen into the shroud (Figure 3). To simulate high temperatures (+150 ℃) in the lunar environment, halogen lampswere installed in the DTVC.



    2. [Figure 1] Large-scaledusty thermal vacuum chamber (DTVC)


[Figure 2] Creation of vacuum in ground by controlling decompression rate

[Figure 3] Simulating extreme-temperature environments



Infrastructure construction technologies using locally available planetary materials

Above all else, the construction of a lunar base requires the availability and use of the right construction materials. Transporting materials from the Earth to the Moon to construct a lunar base would result in astronomical costs; as such, the most efficient way of securing materials for lunar base construction is to utilize the regolith locally available on the Moon. However, a solidification process is necessary in order to use lunar regolith as a material for construction; this solidification process is done through sintering. The sintering process involves heating regolith in its powder state to a temperature that is close to its melting point. The heated powder is then compacted to create a single lump. This process can be used to produce a type of construction material, made using only locally available materials, without the need for any binders. Using this method, researchers heated artificial lunar regolith to temperatures of 1,100 ℃ or more in a microwave sintering furnace. The uniaxial compressive strength of the resulting material was measured to assess its usability as a construction material and was found to have, on average, a strength of 20MPa or greater (Figure 4). Research to fabricate blocks of a size that can actually be used for construction is currently underway.


[Figure4] Microwave sintering apparatus and sintered body of lunar regolith


Technology for the informatization of planetary surface construction spaces

The aim of this study was to develop unmanned, vehicle-based, 3-dimensional topographical informatization techniques for the creation of high-precision, 3-dimensional topographic maps, which are necessary to complete engineering and construction projects on the surface of the Moon. Self- and system-calibration was performed by master cameras mounted on unmanned vehicles, optical lens distortion was corrected, and the relative positions of the cameras were determined. A simulated planetary surface comprised of craters, boulders, hills, pebbles, and soil was created in the KICT’s SOC Experiment Center, and testing was performed on the unmanned topographical informatization techniques (Figure 5)..

[Figure 5] Unmanned vehicle and test site for unmanned topographical informatization technology development

[Figure 6] Development of deep learning-based target object/area recognition technology, and cross-image subject identification and sync technology


Development of planetary geological survey equipment and planetary subsurface informatization technologies

Landersand rovers need to be equipped with drilling equipment in order to analyze theice and subsurface resources located at the poles of the Moon. These devices must be small, lightweight, low-power, highly efficient, and high-performance units in order to function properly under the extreme conditions of the lunar environment. Researchers have developed a prototype drilling apparatus able to operate in atmospheric and cold environments. For ease of transport, the prototype was created to be 0.27 m3 in size with a weight of just 18.5 kg; it was also designed to consume only 44.4 W in power. Preliminary testing of the prototype drilling apparatus was performed using artificial ice in a freeze chamber. This preliminary testing was followed by field testing in which the prototype was used for drilling sea ice and frozen soil near Jangbogo Station in Antarctica under low-power, low reaction force, and waterless conditions (Figure 7). A drilling reliability of 60% or greater was achieved at between 50 and 100N vertical reaction force and 25 to 125 RPMs.


[Figure 7] Configuration of prototype drilling apparatus for planetary subsurface exploration; drilling sea ice and frozen soil at Jangbogo Research Station in Antarctica