To tell the story of the first American in space, the Museum has conserved and digitized the Mercury suit Alan Shepard wore during the first American human spaceflight in 1961. The suit will be displayed in the new Destination Moon exhibition scheduled to open this fall when our National Mall building reopens. Shepard’s suit will join Neil Armstrong’s spacesuit (and many other suits planned for display in the new gallery) to show how an extraordinary combination of motivations, resources, and technologies made it possible for people to walk on the Moon.
The conservation team began examining the artifacts to determine the next steps toward developing a treatment plan to stabilize the suit and prepare it for display. Determining how stable the materials are relies on non-destructive analysis, research, and experience with similar suits in the collections at the Museum. Each object is unique and tells a particular story related to a person and mission, and all of this is taken into account when making important decisions regarding returning an object to display, including decisions about what type of mannequin can be safely inserted into the suit for display. The “suit” is broken down into several important components—the helmet, gloves, suit and boots. The boots will be returned to the suit for display, however, the helmet and gloves will not. Decisions on how far to take a conservation treatment involve multiple people. Both the curator and conservation team don’t make these decisions lightly and rely upon each other for input.
During treatment of Shepard’s suit, analysis was undertaken to gain a better understanding of the suit’s construction. In the shoulders and legs seen in the x-rays images, there were continuous metal spirals, which indicate the tubing of the oxygen delivery system. Images of the knee and ankle joints revealed rows of interior lacing. This lacing emerges from the interior through two grommets in the leg and could be pulled to allow Shepard to customize the fit in these regions. Similar lacing is found on the exterior of the suit on the back and on each arm. The exterior lacing is covered with thin white fabric to prevent snagging of the laces while the suit is in use.
After conservation treatment on the suit, the next tasks were the development of a mannequin support for display and digitizing the suit. It underwent an extensive program of 3D imaging by the Smithsonian’s Digitization Program Office with support from the National Air and Space Museum team. This project included three days of photogrammetry and 3D scanning to document the exterior surface of the suit, gloves, boots and helmet. To do this, we mounted the suit in its final display configuration with the boots and gloves in place and the helmet was documented separately.
The documentation and digitization of the suit and associated objects included image capture with photogrammetry, structured light scanning, and laser arm scanning. Photogrammetry was performed in order to capture high resolution surface color images. The process involves taking images in sets of 10° intervals around the object at varying heights from the top to bottom. Cross-polarized photogrammetry was also conducted. This involves taking the same sets of images as the normal photogrammetry but with cross-polarized filters to filter out specular reflectance. This technique captures surface texture and makes it easier to relight the 3D model.
Structured light scanning was utilized to capture surface geometry and color at the medium detail level. And, laser arm scanning was utilized to capture more detailed high-resolution areas of the surface geometry. Due to the reflective surfaces and clear plastic visor, the helmet was captured separately. Using a much smaller light box set up, the team finalized details and documentation by performing similar techniques to those that were used for capturing the suit.
The data gathered through all these techniques will be combined by the Smithsonian’s Digitization team to produce a high-resolution master model. The bulk of the data and color information will come from extensive photogrammetry and the structured light and laser scans will patch in important geometry details. During this final processing, the helmet data will be used to “place” the helmet on the suit in the 3D rendering, so that it can be viewed as it would have been worn by Alan Shepard. The composite 3D model will be adapted for both web and mobile viewing. We plan to make this 3D imagery available by next year.