When planning to shift to the Moon, where would humans live? Prior to the move, one would have to carry all the cement, water and building materials from Earth and build homes first. The entire idea seems practically impossible and this is why a recent study has provided an interesting alternative to all this hard work.Scientists created a ‘Moon cement’ produced with regolith simulants of lunar and Martian soil and let it spend six months outside the International Space Station where it faced vacuum, radiation and temperature variations. After returning to the station, the samples showed no degradation and one composition even recorded compressive strength 35% higher than the controls kept on Earth during the mission.The results were published in the journal Advances in Space Research on May 15, 2026 and detailed by the University of Delaware on July 9, 2026. The study conducted on NASA’s MISSE-20 mission, evaluated the internal structure, chemical composition and mechanical strength of geopolymers after returning to Earth.
Not from the moon
Despite the name used for ease of understanding, the material was not produced with true regolith brought from the Moon’s surface. Researchers made use of simulants manufactured to reproduce the chemical and mineral characteristics of different types of extraterrestrial soil.These materials were combined with an alkaline solution to form geopolymers. Geopolymers are binders obtained by the reaction between aluminosilicate-rich materials and alkaline solutions. The process connects the particles into a solid structure without requiring the traditional manufacturing of Portland cement. The goal was to develop an alternative to conventional cement, that in the future can be used to manufacture directly on the Moon with resources available on site. Norman Wagner, a professor of Chemical Engineering at the University of Delaware, described regolith as a clay-like material rich in silicates. Its abundance on Earth, the Moon, and Mars makes this raw material relevant for research on construction outside the planet.
Trip to space
The team created four samples made with lunar simulants, Martian simulants and high-quality metakaolin
The team produced four types of samples. Two were made with lunar regolith simulants called Lunar Highlands Simulant 1 or LHS-1 and Black Point 1, identified by the acronym BP-1. Another composition used the Martian simulant MGS-1C, while the fourth group was produced with high-purity metakaolin. This comparison allowed verification of whether different raw materials would react the same way to the space environment.The samples were manufactured in the form of thin plates and installed on the exterior of the International Space Station. They participated in the MISSE-20 mission, a program used to evaluate materials and components directly in the orbital environment.During the mission, the experimental lunar cement faced near-vacuum pressures, radiation, and repeated temperature fluctuations. The study recorded absolute values between −11.75 °C and 35 °C. The temperature also varied by about 15 °C with each orbit of the station around Earth. After approximately half a year, the plates returned to Earth for mechanical, chemical, and imaging examinations.
Future of space?
The geopolymers produced with the lunar simulants LHS-1 and BP-1 and with the Martian simulant MGS-1C showed no signs of degradation caused by the six months spent in low orbit. The results revealed they maintained their chemical structure and mechanical strength.Moreover, the sample made with LHS-1 and sent to space showed a compressive strength of 60.3 megapascals. The control group kept on Earth recorded 44.7 megapascals. The difference corresponds to approximately 35%. This means that the sample returned with a higher measured strength, but it does not allow us to conclude that the space environment directly strengthened the material. Researchers attributed the statistically significant change in LHS-1 samples to the thermal procedure performed before launch, known as the bakeout test. This treatment is used to reduce volatile materials before a sample is sent to space. Therefore, the 35% greater strength should not be presented as proof that the vacuum or radiation increased the strength of lunar cement.The samples produced with high-purity metakaolin darkened due to oxide attack and developed cracks due to the vacuum treatment applied before the flight.The analysis supports the continuation of studies, although it does not yet demonstrate that the material can be reliably produced and cured directly on the Moon. Transporting cement, water and other aggregates needed for a lunar base from Earth would require a large cargo capacity along with immense expenditure. This is why space exploration programs study the use of resources on site, a concept known as ISRU.This time, the samples sent to the station were produced and initially cured before orbital exposure. Now, it needs to be discovered how to mix, mold and harden geopolymers under conditions similar to the Moon’s surface. Go to Source
