A process is proposed for fabrication of lightweight spherical reflectors in outer space for telescopes, radio antennas, and light collectors that would be operated there. The process would obviate the relatively massive substrates and frames needed to support such reflectors in normal Earth gravitation. According to the proposal, fabrication of a reflector would begin with blowing of a bubble to the specified reflector radius. Taking advantage of the outer-space vacuum as a suitable environment for evaporative deposition of metal, a metal-evaporation source would be turned on and moved around the bubble to deposit a reflective metal film over the specified reflector area to a thickness of several microns. Then the source would be moved and aimed to deposit more metal around the edge of the reflector area, increasing the thickness there to ≈100 µm to form a frame. Then the bubble would be deflated and peeled off the metal, leaving a thin-film spherical mirror having an integral frame. The mirror would then be mounted for use.
The feasibility of this technology has been proved by fabricating a prototype at JPL. As shown in the figure, a 2-in. (≈5-cm) diameter hemispherical prototype reflector was made from a polymer bubble coated with silver, forming a very smooth surface.
This work was done by Yu Wang, Jennifer Dooley, and Mark Dragovan of Caltech and Wally Serivens of the University of South Carolina for NASA’s Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Manufacturing category. NPO-30649
This Brief includes a Technical Support Package (TSP).
Fabrication of Spherical Reflectors in Outer Space
(reference NPO-30649) is currently available for download from the TSP library.
Don't have an account?
Overview
The document titled "Fabrication of Spherical Reflectors in Outer Space" from NASA's Jet Propulsion Laboratory outlines innovative technologies for creating ultra-lightweight light collectors, antennas, and space telescopes using in-space bubble blowing and evaporation techniques. Traditional designs for these devices often rely on heavy frames and substrates to withstand Earth's gravity, making them cumbersome for space missions. However, the document proposes a method that leverages the unique conditions of space, where gravity is minimal, to create lightweight structures.
The process begins with the blowing of a soap bubble in space, which can achieve a nearly perfect spherical shape due to the absence of wind and gravity. This spherical film serves as the foundation for the light collectors, antennas, and telescopes. The high vacuum of space is conducive to thin film evaporation, allowing a metal film to be deposited onto the bubble's surface. The smoothness of the bubble ensures that the metal film can be applied unevenly without compromising the quality of the surface.
Once the desired thickness of the metal film is achieved, a thicker ring is deposited around the edge to create a frame that can be handled. This innovative approach not only reduces the weight of the structures but also enhances their performance. For instance, lightweight light collectors can decrease the size of solar cell panels, thereby increasing the electrical energy supply for satellites. Similarly, larger antennas can improve sensitivity and reduce power requirements, while bigger aperture telescopes can capture high-resolution images.
The document emphasizes the advantages of this technology for NASA's space missions, highlighting its potential to revolutionize the design and functionality of space-based instruments. By eliminating the need for heavy materials, the proposed method allows for more efficient and effective space exploration.
In summary, the document presents a groundbreaking approach to fabricating lightweight space instruments through in-space bubble blowing and evaporation, promising significant advancements in the efficiency and capability of light collectors, antennas, and telescopes for future NASA missions. This technology not only addresses the challenges posed by traditional designs but also opens new avenues for exploration and scientific discovery in space.
