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Sheldahl Aerospace Technologies has supported the space industry since 1958. Our space heritage is unsurpassed in the industry providing thin film material to space missions worldwide.
Sheldahl fabricated the inflatable structure on NASA’s first satellite mission- Project Echo – NASA’s first satellite project with initial involvement beginning in 1958.
Sheldahl…From the beginning.
Technologies
- MLI Blanket Material
- Blanket Closure Tapes
- Radiator Materials
- Laminated Materials
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MLI BLANKET MATERIAL
Sheldahl MLI (Multilayer Insulation) are metalized substrates, typically with aluminum.The typical substrates are polyester (PET) and polyimide (Kapton) films ranging from 0.25,0.3,1,2,3 and 5 mil. thicknesses.They can be metalized single sided for use as first- or second-surface mirrors.Single sided coatings will have low emittance and solar absorptance on the metal side and higher emittance on the uncoated side, depending on the thickness.
Single sided coatings can be used as the outside layer of an MLI and can be coated with other materials like ITO or SiOx on the uncoated side. Double sided metallization is also available.These coatings are used in the interior of the MLI with a mesh spacer between the layers.Gold metallization can be used in place of Aluminum if needed.These constructions can also be perforated in a variety of patters and hole sizes.See our RED BOOK for further details.
BLANKET CLOSURE TAPES
Sheldahl provides a wide variety of MLI blanket closure tapes that include low emittance first surface metalized tapes, second surface aluminized polyimide tapes, and various polyimide tapes. Common pressure sensitive adhesives provided include acrylic, conductive acrylic, and silicone pressure sensitive adhesives.
Tapes available in multiple widths.
Perforation is an option that is offered to facilitate air passage during launch and provides a 1.1% open area. For those concerned with salt fog on aluminum first-surface tapes, an acrylic overcoat can be provided for additional protection.
RADIATOR MATERIAL
Sheldahl spacecraft radiator material are metalized substrates, typically FEP.They are designed to be used as low solar absorptivity, high emissivity materials to keep spacecraft cool in high radiation environments. Aluminum or silver are the standard metal layers used. Selection typically depends on the degree of solar reflectivity required. The silver coatings are protected from corrosion by an overcoat of Inconel. The emittance is control by the FEP film thickness selected.
Typical FEP thicknesses are:
0.5, 1, 2, 3, 5 and 10 mil.
The space-facing FEP surface can be coated with ITO for static control or SiOx for atomic oxygen protection. Additionally, the materials can be combined with a PSA for use as a tape or sticker.
Perforation of these material for venting and z-axis conductivity is also offered. Large and small volumes at wide or narrow widths of this material can be accommodated. As an alternative radiator construction, Sheldahl also offers an aluminized Kapton film with an overcoat of SiOx tuned to a specific emissivity range. See our RED BOOK for further details.
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LAMINATED MATERIALS
For some applications, metallized films do not always possess the sufficient properties of themselves. In such cases, it is necessary to reinforce these materials with films or fabrics. An open weave scrim is often used to provide tensile and tear strength with minimal added flight weight. Closed-weave, glass fabrics are sometimes used for heat shielding and added thermal strength in applications with very high intermittent temperatures. In other cases, a film of a specific thickness and modulus may be laminated to move a sensitive coating toward the neutral axis to improve flexural performance.
Sheldahl has numerous adhesives available, but for aerospace laminates, two adhesive systems are primarily used. For applications with an intermediate temperature range, Sheldahl’s A528 adhesive, a thermally cured polyester, is sufficient. For high temperature applications, Sheldahl’s proprietary 3P adhesive is used. This system also has excellent radiation resistance as evidenced by testing for the long-defunct SSC project. Both of these adhesives have extensive flight history spanning decades. They have been formulated by Sheldahl R&D and the backbone polymer for 3P is actually synthesized in-house. With a long history of materials science, the Sheldahl technical staff can assist in the design of laminate composites required in new applications.
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