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NASA’s Artemis II mission is set to return astronauts to the lunar surface, marking the first crewed visit since the Apollo 17 mission in 1972, with a target launch no earlier than April 2026.
The Artemis II mission will employ NASA’s Space Launch System, a powerful rocket designed for human exploration beyond Earth’s atmosphere. The mission will see a crew of four travel aboard the Orion spacecraft, which was successfully tested during the Artemis I mission, when it orbited the moon and returned safely to Earth.
Before Artemis II commences, NASA aims to deploy two preliminary missions tasked with exploring the lunar south pole for essential resources that could support sustained human presence on the moon and foster new scientific breakthroughs.
As a planetary geologist, my interest lies particularly in the data provided by Lunar Trailblazer, one of the two forthcoming missions. This mission’s findings will enhance our understanding of the processes of water formation and its dynamics on rocky celestial bodies.
Scientific Foundations of Lunar Exploration
The mission known as PRIME-1 (Polar Resources Ice Mining Experiment) is set for launch in January 2025. This mission will deploy a lunar lander equipped with key instruments.
The lander will be fitted with two pivotal devices: The Regolith and Ice Drill for Exploring New Terrain (TRIDENT) and the Mass Spectrometer for Observing Lunar Operations (MSOLO). TRIDENT is designed to penetrate up to one meter into the lunar surface to retrieve soil samples, while MSOLO will analyze these samples for their composition and water content.
In tandem with PRIME-1, the Lunar Trailblazer satellite will also launch on a Falcon 9 rocket, optimizing the use of resources through a rideshare model akin to a multimillion-dollar satellite Uber pool.
Led by principal investigator Bethany Ehlmann, the Lunar Trailblazer team comprises scientists and students from Caltech, working under NASA’s Small, Innovative Mission for Planetary Exploration (SIMPLEx) framework. These initiatives aim to conduct valuable experimental operations without exceeding a budget of $55 million per mission, although Trailblazer has exceeded this cap slightly, coming in at approximately $80 million—still a fraction of the typical costs associated with other NASA missions.
Leveraging Technology with Small Satellites
Years of investment into the development of small satellites, or SmallSats, have paved the way for innovative missions like Lunar Trailblazer. These small platforms can gather highly specific measurements that enhance the analysis offered by larger instruments.
For instance, NASA’s TROPICS mission employs a network of SmallSats to collect vast quantities of data simultaneously, attributing to a more comprehensive understanding of both Earth and lunar conditions. With multiple SmallSats operating together, they can achieve high-resolution measurements across the surfaces they monitor.
The cost-effective and risk-tolerant nature of SIMPLEx missions allows researchers to tackle scientific inquiries that would traditionally be deemed too ambitious. For Lunar Trailblazer, the use of commercial off-the-shelf components is instrumental in maintaining budget constraints.
The insights gained from these lower-cost experimental missions could dramatically shift our understanding of solar system formation, along with the moon’s geological history, with Lunar Trailblazer focusing on lunar mapping specifically.
A Historical Perspective on Lunar Water Discoveries
The moon has captivated scientists for centuries, leading to observations dating back to the mid-17th century when astronomers misidentified ancient volcanic formations as lunar mare, mistakenly believing they to be seas.
In the late 19th century, astronomer William Pickering concluded that the moon could not harbor water due to its lack of atmosphere, speculating that any surface water would evaporate. However, the landscape of lunar research dramatically changed in the 1990s with NASA’s Clementine mission, which found evidence of water ice on the moon, particularly in the permanently shadowed regions.
This initial discovery ignited further missions dedicated to exploring lunar water, notably the Lunar Prospector launched in 1998 and the Lunar Reconnaissance Orbiter in 2009. Additionally, India’s Chandrayaan-1 mission, equipped with the Moon Mineralogy Mapper, unexpectedly discovered liquid water in sunlit regions on the moon.
These missions have collectively advanced our understanding of how hydrous minerals and water ice are distributed across the lunar landscape, particularly in colder, shadowed areas.
Exploring the Dynamics of Water on the Moon
A key area of inquiry is how the state and temperature of lunar water fluctuate with shifts in sunlight and crater shadows. The Lunar Trailblazer mission will carry two key instruments, including the Lunar Thermal Mapper (LTM) and an advanced version of the M3 instrument known as the High-resolution Volatiles and Minerals Moon Mapper (HVM3).
The LTM will assess surface temperatures, while the HVM3 will analyze how lunar rocks interact with light to identify and differentiate forms of water, whether liquid or solid. The combination of data from these instruments will provide both thermal and chemical insight into hydrous lunar rocks, offering a detailed view over the lunar day, consisting of roughly 29.5 Earth days, to observe how water composition varies with time of day and geographic location.
This comprehensive analysis aims to illuminate the phase of water, whether it exists as ice or liquid.
Significance of Lunar Water Research and Future Directions
There are three prominent hypotheses regarding the origin of water on the moon. One possibility is that it has resided in the moon’s mantle since its inception, gradually making its way to the surface through geological processes.
An alternative theory posits that water might have been delivered to the moon by asteroids and comets striking its surface, while another suggests that interactions with the solar wind could generate water.
Findings from Lunar Trailblazer could provide crucial insights into these theories and assist scientists in addressing fundamental questions regarding the behavior of water on rocky bodies like the moon. Understanding these dynamics is essential for determining whether future lunar explorers could harness local water resources.
Source
phys.org