Lunar Sample Laboratory Tour
Between 1969 and 1972, six Apollo space flight missions brought back 382 kilograms (842 pounds) of lunar rocks, core samples, pebbles, sand and dust from the lunar surface. The six space flights returned 2200 separate samples from six different exploration sites on the lunar surface. In addition, three automated Soviet spacecraft, named Luna 16, Luna 20, and Luna 24 returned important samples totaling 300 grams (approximately 3/4 pound) from three other lunar sites.
The Lunar Sample Laboratory Facility, which was built in 1979, is the chief repository for the Apollo samples. It was constructed to provide permanent storage of the lunar sample collection in a physically secure and non-contaminating environment. The facility consists of storage vaults for the samples, laboratories for sample preparation and study, a vault for sample data and records, and machinery to supply nitrogen to the cabinets in which the samples are stored and processed.
Click on any of the following tabs to tour the Laboratory
- Change Rooms & Air Shower
- Pristine Sample Lab
- Pristine Sample Display Case
- Core & Saw Room
- Pristine Corridor & Vault
- Experiment Lab
- Return Sample Vault
- Observation Room
Change rooms & air shower
Personnel don protective clothing in the Clean Change Room
The first stop on our tour is the Normal Change Room. When we first enter the change room, we must wipe our shoes on the mat next to the door and then don overshoes or "booties." Next we must remove all jewelry. We follow these procedures in order to prevent contaminating the lunar samples with particles and other material from our bodies and clothing. Airborne dust is the chief way in which contaminating material could reach the lunar samples. Each cubic foot of ordinary room air commonly contains 100,000 particles of all kinds. The coarser particles eventually settle as dust, but the finer particles stay suspended indefinitely. New particles are generated continuously; for example, dried skin flakes from people, lint and dust from clothing, material carried by shoes and abraded from the floor, metal particles from screw threads, etc.
Before entering the lab, everyone must remain in the air shower for 1 minute
The Moon is composed of the same chemical elements as the Earth, but in different proportions. Some elements which are very common on Earth occur in lunar samples in very small quantities. A tiny speck of gold from a wedding ring would increase the concentration value measured for gold in a lunar sample many times over the true value and would lead to a false interpretation of the sample's origin.
A number of measures are taken to keep the air clean in the lunar laboratories. The air is circulated through special filters to remove all suspended particles. To keep unfiltered air from entering laboratories, filtered air in the laboratories and vaults is kept at slightly higher pressure than the atmospheric pressure used in the rest of the building. The particulate concentration of the air in the various areas is monitored regularly, and levels routinely test better than performance requirements. Therefore, we have tangible results that the contamination control measures that we take are successful.
If we were entering the Experiment Laboratory or the Return Sample Vault at this point, we would put on smocks, hats, and a second pair of shoe covers before leaving this room. However, we will proceed first into the Pristine Laboratory and Vault areas. The contamination control requirements are stricter there than for the Experiment Laboratory and Return Sample Vault, and, before entering these areas, we must proceed into a second change room known as the Clean Change Room. In this room, we put on specially cleaned clothing which includes nylon coveralls or "bunny" suits, hats, gloves, and a second pair of overshoes. Next we enter an air shower where we remain for 1 minute while filtered air is blown across our bodies from top to bottom.
Pristine Sample Laboratory
Stainless steel glove box cabinets line either side of the Pristine Sample Laboratory. The positive pressure inside the cabinets created by flowing nitrogen causes the rubber gloves to extend outward from the cabinets.
From the air shower we enter the Pristine Sample Laboratory Laboratory. It is important to note that the Lunar Sample Laboratory Facility is a working laboratory, not a museum. In this room, pristine lunar samples for research, for education, and for display are prepared for distribution to recipients located at 85 universities and institutions throughout the world. We presently have international customers in Australia, Canada, England, France, Germany, Hungary, India, Ireland, Japan, and Switzerland. Hundreds of scientists, professors, and students from all over the world attend the annual Lunar and Planetary Science Conference at which new lunar and planetary research findings are discussed.
A lunar sample processor prepares to begin work by placing her hands in the rubber gloves attached to the cabinet.
“Pristine” samples, or samples which have not been out of the laboratory since they were returned from the Moon, are processed in specially manufactured stainless steel cabinets filled with flowing nitrogen gas which has been carefully purified to remove water and oxygen. Before the samples were collected, they had been in a vacuum on or near the lunar surface for millions to billions of years. If the samples were exposed to the Earth’s humid atmosphere, they would react with it. Small grains of iron in the lunar samples would combine with oxygen to form rust; glasses and minerals would combine with the water in air to form clays. Nitrogen gas is used in the cabinets because it provides an environment with minimum reaction to the samples.
Lunar sample processor examines a sample in the Pristine Sample Laboratory
Rubber gloves made of Neoprene, which are fitted to holes in the sides of the cabinets, let workers reach the samples inside the air-tight, sealed cabinets. The nitrogen gas pressure is slightly greater than the air pressure. Should a leak develop, nitrogen would rush out from the cabinet and prevent the air from entering and contaminating the samples. Since a serious leak could flood the laboratory with nitrogen gas, the oxygen level in the room air is carefully monitored for personnel safety. Because oxygen and water in air slowly permeate the rubber gloves and enter the cabinets, the nitrogen is kept flowing in order to prevent concentrations of these reactive gases from building up inside the cabinets. Automatic hourly testing of each cabinet assures that the water and oxygen concentrations are maintained at less than 20 molecules of oxygen and 50 molecules of water for every one million molecules of nitrogen.
These are typical tools used for processing lunar samples. Shown top to bottom are: hammer, chisel, tweezers, scoop, and Teflon brush.
To avoid cross-contamination of samples from different places on the Moon, samples from different missions are not processed together in the same cabinet, but one or more cabinets are designated for processing samples from a particular mission. When cabinets become dusty from extensive processing or are needed for processing samples from a different mission, they are cleaned using ultra-pure water.
Lab processors photograph and document sample processing in a data pack
The nitrogen cabinets are equipped with tools, containers, and other pieces equipment which have been specially cleaned and packaged in hermetically sealed bags. The materials which are deemed acceptable for the manufacturing of these items are carefully considered. The only materials which are allowed to touch the samples are aluminum, stainless steel and Teflon. Teflon gloves are worn over rubber gloves used for picking up rocks. Samples are packaged in Teflon bags, plastic vials, aluminum or stainless steel containers. Two hermetically sealed Teflon bags are placed on the outside of all containers with samples slated for storage or distribution to a Principal Investigator.
All sample processing is carefully documented in folders called data packs. Pieces which have been removed from the original sample are assigned new sample numbers, and the masses for all samples are accounted for to the nearest 10 milligrams. Photographs are taken of the samples before and after subdivision, and the orientations of new pieces relative to the original sample are recorded as accurately as possible.
Pristine Sample Laboratory Display Cabinet
The Pristine Sample Laboratory display cabinet is located at one end of the Laboratory. This cabinet contains one Apollo 16 and two Apollo 15 samples which are representative of the rocks in the lunar sample collection. Note that this cabinet represents one exception to the rule that samples from different missions are not housed in the same cabinet at the same time.
Lunar sample processors discuss samples in the Pristine Sample Lab display cabinet
Apollo 15 Sample 15459, a 5.9 Kg Regolith Breccia
Apollo 15 Sample 15459
15459, a 5.9 kg rock, was collected just inside the rim of a 100-meter diameter crater on the foot of the mountains overlooking the Apollo 15 landing site. The rock is a tough, coherent regolith breccia - composed of rock fragments and other soil components such as small glass spheres and glass shards bonded together in a glassy matrix. Breccias such as 15459 are formed in ancient regoliths by meteorite impacts in which heat and pressure bond rock fragments and soil particles together. Impacts not only fuse rocks from regolith particles, but break rocks into small fragments and fling these fragments and blobs of molten glass some distance into the surrounding area. Rock fragments, called clasts, found inside breccias like 15459, can represent material thrown from the surrounding areas by prior impacts. Clasts in 15459 are diverse; some are mare basalts from the lava-filled plains and others are from the older highlands. One basalt clast crystallized 3.3 billion years ago, although the age of formation of the breccia now called 15459 might be as recent as 500 million years ago or less.
Apollo 15 Sample 15556, a 1.5 Kg Basalt
Apollo 15 Sample 15556
15556, a 1.5 kg rock, was plucked from near the rim of Hadley Rille at the Apollo 15 site. From the rim of Hadley, astronauts could see layers of basalt exposed in the wall of the rille, which is interpreted as an ancient lava channel. This medium grained, extremely vesicular basalt is 3.4 billion years old. Since the Moon is so very dry, the volatile gas causing the vesicles (bubble cavities) in this rock and other rocks probably was a mix of oxides of carbon and sulfur dissolved in the molten rock.
Apollo 16 Sample 16016, also known as “Big Muley”. This rock is the largest rock collected during the Apollo missions.
Apollo 16 Sample 61016
61016, at 11.7 kg, was the largest rock collected during the Apollo missions. It was nicknamed “Big Muley” after one member of the geology support team. Apollo 16 landed in the light-colored highlands of the Moon. These highlands regions are generally higher in elevation and composed of older rocks relative to the volcanic plains. These rocks are rich in aluminum and calcium, two of the elements found in the plagioclase mineral anorthite. This specimen is comprised of four different rock types: 1) material of basaltic composition melted during an impact; 2) an impact-shocked anorthosite, thought to be from ancient lunar crust; 3) an impact shock-melted glass rich in aluminum and calcium; and 4) a darker glass coating. Some components in this rock may be as old as 4.5 billion years. Zap pits, or tiny craters created by micrometeorites striking the lunar surface at very high speeds, are prominent on one side of this rock, but absent on the other. Since the pitless side was facing up when the astronauts found the rock, it must have only recently been turned over by natural processes.
Core & Saw Room
Next we will look at the Core & Saw area of the Pristine Sample Laboratory. This area serves two functions, the dissection of cores and the bandsawing of rock samples. These two operations are never done simultaneously because the vibrations produced by the bandsaw would disturb the very sensitive core samples.
Apollo 16 core 64002 is being dissected. Soil from each millimeter interval is removed and seived to remove particles greater than 1mm. Then the two sieve fractions are weighed and any interesting particles are photographed.
The lunar surface is covered with a layer of crushed and fused rock called regolith. The finest material is called soil, although it does not have organic material like earthly soil. The soil is a result of continual meteorite impacts which break up, melt and vaporize rock. Each impact causes the formation of a crater and throws material, called ejecta, which blankets a circular area around the crater. Occasionally, one ejecta blanket covers another, preserving layers in the soil which can be tied to specific cratering events. However, most often the numerous small meteorites, down to sand size, stir and mix the layers in a process known as "gardening." The top soil surface accumulates radiation and particles spewed out by the Sun. The Apollo astronauts collected tubes of soil, called core samples, from 24 locations on the Moon. These drill cores went as deep as 3 meters (10 ft) into the soil. A soil layer found at the bottom of one drill core was deposited about 500 million years ago and contains evidence about the Sun's behavior at that time.
To capitalize on the wealth of information held within the cores, great care must be taken in opening them and in removing samples for study. X-ray pictures through the metal core tubes give the first data about the core samples. Then, inside a nitrogen cabinet, the core material is pushed out of the tube into a horizontal receptacle. Millimeter by millimeter the material is examined, photographed, and then carefully sliced away and put into separate containers for each interval. A small portion of the material from each interval is distributed for the first analyses, which will guide planning for subsequent studies. A strip along the length of each core is left intact and embedded in plastic as a permanent record of the structure. It takes four to six months to dissect and describe one core section. The 24 cores were collected in 54 separate tubes, 4 of which have yet to be opened and examined for the first time.
This Apollo 15 basalt, 15555, is ready for its first saw cut.
Many studies require precise locations of subsamples within a rock. For example, energetic radiation from the Sun and from space produce nuclear reactions within lunar samples. To deduce the energy of radiation that produced a reaction, it is essential to know the depth within the rock where the reaction occurred - the deeper the penetration of the radiation, the greater their energy. A piece cut across the middle of a rock enables studies of radiation from the Sun and other stars from the least energetic at the surface to the most energetic at the bottom of the rock.
The processor is photographing the sample in the bandsaw cabinet.
Sawing a rock is the only way to produce such pieces and obtain accurately located pieces for other studies. In addition, sawing reveals the complex internal structures of rocks such as breccias.
Special bandsaws have been developed for doing this kind of work. To protect the rocks from contamination and reaction with air, the saws are enclosed in a nitrogen cabinet. The rock is clamped to a sliding table and advanced into a stainless steel blade which has diamonds in the cutting edge. Since the lubricants and cooling liquids normally used in sawing rocks would badly contaminate the lunar samples, the sawing is done dry and very slowly to prevent overheating.
Pristine Corridor & Vault
The door to the Pristine Vault is a bank-style door with two combination locks. It remains closed except when samples are being transferred.
When a sample is being transferred into a cabinet in the Pristine Sample Laboratory (right) the outermost bag is removed and the sample is held with teflon gloves and placed into an airlock and is passed into the lab from the Pristine Corridor (left)
From the core and saw area in the Pristine Sample Laboratory, we will proceed to the Pristine Corridor. The corridor's primary function is to provide a clean environment for transferring samples and equipment into or out of the nitrogen processing cabinets in the Pristine Sample Laboratory. The cabinets are equipped with transfer chambers, or airlocks. These chambers have an inner door which opens into the cabinet, and an outer door which opens to the Pristine Corridor. When samples or equipment are transferred into a cabinet, the outer door is opened, the outermost bag is removed from the item being transferred, and it is placed in the airlock. Teflon overgloves are worn to handle the items once the outer bags are removed. The outer door is sealed, and the airlock is purged for 5 minutes. Then the inner door may be opened and the articles transferred into the cabinet.
This view of the Pristine Sample Vault shows about one-third of the cabinets housed there.
The Pristine Sample Vault is located in the Pristine Corridor. During hurricane threats, a water-tight door is bolted into the frame of the vault door in order to further protect the samples in the vault from the possibility of rising water.
The Pristine Sample Vault is one of two sample vaults housed in the Lunar Sample Facility. The second vault is used to house samples that have been returned by investigators after their analyses. Both vaults are designed to protect the collection of samples from damage by natural hazards such as tornadoes and hurricanes.
The Pristine Sample Vault is equipped with nitrogen glove-box cabinets similar to those in the Pristine Sample Laboratory, except that they are designed for storage rather than processing. As in the Pristine Sample Laboratory, specific cabinets are designated to hold samples from specific missions. The samples are stored in stainless steel trays which are sealed with numbered security tags. Two persons must verify that the contents of the tray are accurate before the security tag can be affixed. A database containing the locations of all samples, along with other information, is maintained so that samples can be easily retrieved for processing and distribution. Approximately 26,000 samples representing 75% of the mass of the Apollo collection are located in the Pristine Sample Vault. A representative sampling of the collection is stored at another remote location so that the entire collection would not be lost in the event of a major catastrophe at Johnson Space Center.
A visiting lunar scientist uses the Experiment Laboratory to study lunar soils with a miniature optical microscope which produces digital images.
The Experiment Lab is used for tests and measurements on particularly large or rare lunar speciments. Visiting scientists working with these specimens can take advantage of the Lunar Sample Laboratory's unique environmental controls, as well as the assistance of people experienced in the care of lunar materials. In the past, visiting scientists have measured the heat conduction through unopened core tubes (to determine the rate of cooling of the Moon's interior) and have measured the light reflected from soils and rocks.
Processors are removing samples from a cabinet in the Return Samples Vault.
Approximately 48,000 samples that have been returned by investigators after analysis are stored in the Return Sample Vault. These samples represent about 7.5% of the mass of the Apollo collection. Stainless steel upright cabinets containing two stacks of drawers are used to store the samples. Plastic boxes are used to further organize the samples within the drawers to make the task of locating them easier. Unlike the cabinets in the Pristine Sample Vault, these cabinets are exposed to room air since the samples themselves were exposed to the Earth's atmosphere when they were located in the investigators' laboratories.
Windows on all sides of the Observation Room allow views into the laboratory and change rooms areas.
The last stop on our tour is the Observation Room. No special clothing is required for entry into the observation room because no samples are kept here. This room has windows which allow occupants to view the Pristine Sample Laboratory, the Clean Change Room, and the Transfer Room. An airlock between the Observation Room and the Pristine Lab is used for transferring samples, tools, containers, and documents into and out of the laboratory. This area is also used for reviewing documents to verify that sample allocations comply with investigators' requests before they are actually shipped.
The Observation Room also houses readouts which display the alarm status for the oxygen and water contents of the cabinets as well as the oxygen levels in the air in the various areas of the facility.