Moon Rock Analysis of NASA's Apollo 17 Mission
In 2020, almost 50 years after the Apollo missions returned lunar material to Earth, ESA (European Space Agency) experts are helping to uncover the secrets of two previously unopened samples to learn more about ancient processes on the Moon — and to refine and practice techniques for future sample return missions. 1)
With one sample already being analyzed, preparations are now being made to open the second later this year. This work focuses on rock and soil retrieved during the 1972 Apollo 17 mission, and is part of NASA’s ANGSA (Apollo Next-Generation Sample Analysis) program, which takes advantage of advanced analytical techniques.
Since the Apollo era, all samples that were returned to Earth have been carefully stored in the laboratory to preserve them for future generations. Most samples have been well studied, and many are the subject of ongoing research. However, NASA also made the decision to keep some samples completely untouched as an investment in the future, allowing them to be analyzed with more advanced technologies as they are developed. These include samples that remained sealed in their original containers, as well as some stored under special conditions, all intended to be opened and analyzed with more advanced analytical technologies than were available during Apollo. 2)
The unopened Apollo samples were collected on Apollo 15, 16 and 17 missions. Two of those samples, 73002 and 73001, both collected on Apollo 17, will be studied as part of ANGSA. Advances in techniques such as non-destructive 3D imaging, mass spectrometry and ultra-high resolution microtomy will allow for a coordinated study of these samples at an unprecedented scale.
Samples 73002 and 73001 are part of a two-foot long “drive tube” of regolith (rock and soil) that collected from a landslide deposit near Lara Crater at the Apollo 17 site. The samples preserve the vertical layering within the lunar soil, information about landslides on airless bodies like the Moon, and a record of the volatiles trapped within lunar regolith, perhaps even those escaping from the Moon along the Lee-Lincoln Scarp, a fault at the Apollo 17 site.
“Opening these samples now will enable new scientific discoveries about the Moon and will allow a new generation of scientists to refine their techniques to better study future samples returned by Artemis astronauts,” said Francis McCubbin, NASA’s astromaterials curator at Johnson. “Our scientific technologies have vastly improved in the past 50 years and scientists have an opportunity to analyze these samples in ways not previously possible.”
Figure 1: The ANGSA team members. From left to right: Andrea Mosie (NASA), Juliane Gross (Rutgers University, NASA), Charis Krysher (NASA), Francesca McDonald (ESA), Barbara Cohen (NASA Goddard Space Flight Center), Cari Corrigan (Smithsonian National Museum of Natural History) behind a nitrogen atmosphere glove box containing the newly opened Apollo 17 sample 73002 (image credit: ESA–Francesca McDonald, Ref. 1)
ANGSA consists of nine expert science teams, covering different aspects of sample analysis. ESA scientists and engineers form part of the Consortium for the Advanced Analysis of Apollo Samples, headed by Charles ‘Chip’ Shearer of NASA, one of the ANGSA lead scientists. “ESA collaborators will assist in the characterization of samples, and help us assess how well the lunar material has been collected and preserved,” says Shearer. “Looking ahead, this will help us design future collection and curation procedures for the NASA-led Artemis mission.”
To help achieve ANGSA’s aims, a truly collaborative approach is being employed. “ANGSA ties together those who were involved in the initial curation and analysis of Apollo samples with the next generation of planetary scientists,” says Francesca McDonald, ESA Research Fellow who is coordinating ESA’s ANGSA participation. “Our diverse team includes Harrison ‘Jack’ Schmitt, the only geologist to walk on the Moon, who along with fellow Apollo astronaut Gene Cernan, originally collected the lunar material.”
Figure 2: Photo of Harrison Schmitt on the Moon (image credit: NASA)
Ancient lunar processes
The Apollo 17 landing site lies within the narrow Taurus-Littrow Valley, surrounded by several steep mountains including the North and South Massifs, with a fault scarp, caused by a difference in elevation between the two sides of the fault, cutting across the entire region. The samples were collected from a prominent landslip deposit, which occurred when sediment cascaded down from the South Massif onto the lava filled valley floor. Thus, they contain material from elevated areas that could not have been accessed by astronauts.
To extract the regolith, a 70 cm cylindrical tube was hammered into the landslide deposit to produce a core, which was then separated into two halves on the surface of the Moon.
Figure 3: The Apollo 17 region. Oblique view of 18 km wide and 2.6 km deep Taurus-Littrow valley. Original image by NASA/GSFC/Arizona State University using the LRO (Lunar Reconnaissance Orbiter) image M192703697LR, annotated by Francesca McDonald (image credit: NASA/GSFC, Arizona State University)
The lower half of the section, known as sample 73001, likely contains a region of the subsurface that is cold enough to have trapped loosely bound volatiles, such as carbon dioxide and hydrogen. To try to preserve these precious gases, it was sealed in a vacuum container on the lunar surface and then double sealed in a second vacuum container back on Earth.
The upper portion of the core, sample 73002, was also carefully contained after being collected, but was not vacuum sealed. Both halves have remained in storage, under the expert care of the NASA Astromaterials Curation Team, since being returned.
Figure 4: Moon sample 73002 dissection. Sample 73002, the upper section of a double drive tube core sample extracted from the Apollo 17 landing site (paired with lower section 73001 which still remains sealed in a special vacuum container called a CSVC). The core samples material comes from a lunar landslide event in the Taurus Littrow Valley landing site of Apollo 17. Looking down on the top of the core as it is being extracted in 5 mm intervals along its length. In this image the original location and orientation of a larger rock class is observed (image credit: ESA–Francesca McDonald)
ESA initially has a supportive role in the planning and processes associated with examining the lunar samples, working with the NASA curation team to ensure that the scientists are able to make their highly precise measurements.
Francesca made the trip to NASA’s Johnson Space Center in Houston, USA, in December 2019 to assist in the meticulous dissection of 73002 into subsamples, shortly after it was opened.
During dissection, a detailed record is made of exactly where each subsample comes from within the core, allowing the science teams to make inferences about lunar processes.
To prepare for the opening of the lower portion sample, ESA scientists and engineers are currently working closely with ANGSA noble gas and volatile experts to design a tool to capture any precious gases it may contain.
The results of the analysis will address questions first pondered by Apollo-era scientists. “It is not entirely known what caused the landslip – was it from an impact? Or from movement of the fault?” says Francesca. “If it was to do with movement of the fault scarp, how long ago did this happen? And did this result in any release of gases from within the Moon, which were trapped in the landslide deposit?”
Figure 5: Moon facts: age and composition. This set of infographics illustrates the most frequently asked questions and facts about Earth’s natural satellite (image credit: ESA)
Figure 6: The Moon seen from the International Space Station. The image was taken by ESA astronaut Paolo Nespoli during his second mission to 'MagISStra' on 20 March 2011. Paolo commented on the image: "Supermoon was spectacular from here!" (image credit: ESA/NASA)
ESA is teaming up with international partners to explore the Moon as a destination for both robotic missions and human explorers.
Orion, the NASA spacecraft, will bring humans farther than they have ever been before relying on the European Service Module to return humans to the Moon and take advantage of the new technology for human space transportation. ESA is providing service modules that will provide propulsion, life support, power, air and water, and control the temperature in the crew module.
Luna-Resurs is a partnership with the Russian agency Roscosmos that will carry European technology to land precisely and safely on the Moon and to drill into the surface to extract and analyze samples of the lunar terrain.
The Agency is looking at how we could extract and process local resources into useful products and services, such as drinkable water or breathable oxygen on the Moon.
The Heracles mission of ESA could take off in 2026 to allow us to gain knowledge on human-robotic interaction while landing a spacecraft on the Moon to collect samples with a rover operated from an orbiting lunar gateway and send the samples back to Earth.
Another goal for ANGSA is to understand how effective the double-vacuum sealed containment was, which is paramount for preserving the core’s integrity and the meaningfulness of any subsequent analysis.
With future lunar missions likely to target the polar regions, and the international Mars Sample Return campaign in preparation, this will provide essential information for developing future extra-terrestrial sample containment and curation procedures.
“Utilizing materials present on the Moon is an important part of enabling a future sustained presence for men and women at the lunar surface and for developing onward human exploration of Mars,” explains Dayl Martin, ESA Research Fellow and ANGSA team member.
“Understanding the composition and behavior of lunar material is important to achieve this. The techniques currently being refined as part of ANGSA are set to provide such insights.”
Figure 7: Hunting out water on the Moon. A map of possible water beneath the surface of the Moon’s South Pole, based on temperature data from NASA’s Lunar Reconnaissance Orbiter. ESA is preparing a surface sampling payload that will prospect for lunar water among other resources. It is due to be flown to the Moon aboard Russia’s Luna-27 lander in 2025.
Researcher Hannah Sargeant of the UK’s Open University has made Forbes Magazine’s 30 Under 30 Europe 2020 Innovation list for her work developing an improved method of extracting lunar water in support of the project.
Hannah remarked: “It’s great to see that research into space resources is being recognized and valued in such a public forum ... I’m honored to be a part of this year’s Forbes 30 Under 30 European cohort, but I would like to emphasize that there are many incredible researchers that I work with that are so deserving of a place on this list. The future of space science and technology is definitely in great hands!”
The overall payload is called PROSPECT (Package for Resource Observation and in-Situ Prospecting for Exploration, Commercial exploitation and Transportation). A drill called ProSEED will extract samples, expected to contain water ice and other chemicals that can become trapped at the extremely low temperatures expected; typically -150ºC beneath the surface to lower than -200ºC in some areas.
Samples taken by the drill will then be passed to the ProSPA chemical laboratory, being developed by an Open University team. These samples will then be heated to extract these cold-trapped volatiles and enable follow-up analysis.
Exploration of the Moon by astronauts in the Artemis program will be enabled by using the resources of the Moon, including water ice that can be used to make rocket fuel or oxygen to breathe. Studying these unopened samples may allow scientists to gain insight into the origin of the lunar polar ice deposits, as well as other potential resources for future exploration. They will also gain a better understanding of how well Apollo tools worked, which will help with tool designs for future lunar missions (Ref. 2).
“The findings from these samples will provide NASA new insights into the Moon, including the history of impacts on the lunar surface, how landslides occur on the lunar surface, and how the Moon’s crust has evolved over time,” said Charles Shearer, science co-lead for ANGSA. “This research will help NASA better understand how volatile reservoirs develop, evolve and interact on the Moon and other planetary bodies.”
During the preliminary examination of these unopened Apollo samples, multiple generations of scientists, engineers, and curators will work together to study the samples. Team members who have long NASA experience, some of whom were part of the original teams to first study Apollo samples, will work with younger team members in a true collaboration between past and present generations of lunar explorers. Schmitt, the lone geologist among the Apollo astronauts and lunar module pilot of Apollo 17, which collected sample 73002, is also actively involved in the science team.
“This provides an essential link between the first generation lunar explorers from Apollo and future generations who will explore the Moon and beyond starting with Artemis,” said Shearer.
Since these samples were collected, NASA has continued to study Earth’s nearest neighbor through missions like the Lunar Reconnaissance Orbiter and now has an incredible amount of data about the lunar surface, environment and composition. Under Artemis, the agency will send a suite of new science instruments and technology demonstrations to study the Moon ahead of landing astronauts on the lunar surface by 2024, and establishing a sustained presence by 2028. The agency will build on its past to leverage its Artemis experience to prepare for the next giant leap – sending astronauts to Mars.
1) ”ESA helps analyze untouched Moon rocks,” ESA Science & Exploration, 17 April 2020, URL: http://www.esa.int/Science_Exploration
2) ”NASA Opens Previously Unopened Apollo Sample Ahead of Artemis Missions,” NASA, 6 November 2019, URL: https://www.nasa.gov/feature
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).