Tools, Apollo Lunar Exploration

Working in a space suit is difficult because it reduces the dexterity of its wearer, so specialized tools were developed for Apollo astronauts to use in gathering rock and dust specimens. The grip attainable with spacesuit gloves was restricted and fatiguing for the hands, so all tools were designed with large-diameter, textured grips. Because astronauts could not bend over in their space suits, tools either had a long handle or were attached to an extension handle.

Specimen-Collection Tools

Tongs or a rake were used to collect rocks that were fist-sized or smaller. By raking a large area, an astronaut could quickly gather many walnut-sized rocks free of soil. The goal was to collect many small diverse rock specimens, rather than a few large ones. In contrast, dust samples were acquired by scooping. As astronauts learned about the behavior of the Moon's very fine dust in low gravity, the efficiency of the scoops evolved. The first scoop was boxy. By the Apollo 15 mission, the final design was achieved by an adjustable angle, tapered scoop.

To recover the dust preserved in original layers, as desired by the geologists, core tubes were used. The coring devices were of two types: tubes that were pounded into the ground with a hammer, called "drive tubes," and tubes that were drilled into the ground with a rotary/percussive motor, called "drill cores." Narrow, relatively thick-walled drive tubes were used on the early missions (Apollo 11, 12 and 14). The Apollo 11 drive tubes were designed to acquire "fluffy" dust, not the densely packed dust and rock fragments the astronauts encountered. Consequently, the Apollo drive tubes penetrated only about 10 centimeters (3.94 inches). By the time of the Apollo 15 mission, the drive tubes had been redesigned with larger diameters and thin walls. These tubes acquired dust and rock fragments in nearly undisturbed condition. Drive tubes were used to sample lunar regolith (the dust and rocky material covering the Moon's surface) to a depth of 0.6 meters.

The drill core, used on the last Apollo missions, acquired regolith up to 3 meters in depth with good preservation of stratigraphy . These samples contained a very useful record of the cosmic ray history on the Moon. The drill motor provided a rotary/percussive action to penetrate the regolith and worked quite well. Apollo astronaut Dave Scott had great difficulty pulling the first drill core, but altering the drilling technique on later missions greatly facilitated extraction. In operating the drill, astronauts would add sections as needed to lengthen the drill stem. When extracting the drill stem, the sections would be disconnected and capped, then packaged together for the return to Earth.

Sample Transport Containers

The basic box used to transport the samples from the vacuum of the lunar surface to the atmospheric pressure of Earth was carved from a single block of aluminum and had a triple sealing mechanism consisting of a knife-edgeto-metal seal and two O-ring seals. Two of these boxes were flown on each Apollo mission. Since much more sample material was collected on the later missions, specimens that did not fit into the two boxes were brought back in tote bags.

Most of the smaller samples were placed into numbered individual sample containers before being placed into the transport boxes or bags. To preserve the pristine lunar dust and fragments, some samples were placed into gas-tight cans sealed with a knife-edge-to-metal seal. Many rock and dust samples were placed into numbered Teflon bags with fold-over closures.

Specimen Collection Accessories

A gnomon was a device the astronauts placed on the lunar surface to indicate which way was "up" and provide a color scale. With the gnomon in the pictures taken of rocks on the lunar surface, accurate sun angle and rock color could be determined. A spring scale similar to those used for weighing fish was included to estimate the total sample weight before ascent from the Moon. Little use was made of the lens/brush tool that geologists had thought would be needed to dust off the rocks and examine them through a lens.

The early Apollo missions focused on learning how to work in the lunar environment. The later missions encompassed greater sophistication in the collection of specimens, accompanied by the specialization of tools and containers. Over the course of six Apollo landings, the opportunity to adapt tools based on experience with the lunar environment was especially seen in the evolution of the drive tubes.

see also Apollo (volume 3); Apollo I Crew (volume 3); Apollo Lunar Landing Sites (volume 3); Space Suits (volume 3); Tools, Types of (volume 3).

Judith H. Allton

Bibliography

Allton, Judith H. Catalog of Apollo Lunar Surface Geological Sampling Tools and Containers, JSC-23454. Houston, TX: Lyndon B. Johnson Space Center, 1989.

Wilhelms, Donald E. To a Rocky Moon: A Geologist's History of Lunar Exploration. Tucson: University of Arizona Press, 1993.