Customer’s Application
The customer is a prominent Original Equipment Manufacturer (OEM) specialising in the design and high-volume production of Small Satellite (SmallSat) and CubeSat constellations for commercial Earth observation and telecommunications. The critical application involves the potting and encapsulation of the control electronics within a high-precision star tracker system. This system is fundamental to the satellite’s mission, as it provides the attitude determination and control data necessary to accurately point the main payload, such as a high-resolution camera or a communications antenna.
The Engineering Challenge
The operational environment of Low Earth Orbit (LEO) presents a unique and severe set of challenges that can lead to component failure if not properly addressed:
- Outgassing Contamination: The primary and most critical threat is outgassing. In the high vacuum of space, which can reach pressures below 10-5 Torr, volatile compounds trapped within conventional polymers will vaporise. These gaseous molecules can then travel and condense on cooler surfaces, such as the star tracker’s sensitive optical lenses and charge-coupled device (CCD) sensors. This condensation creates an opaque film that degrades or completely obscures the view of guide stars, rendering the tracker useless. A failure of the star tracker leads to a loss of attitude control, which is tantamount to a total mission failure. This highlights the absolute necessity of a low outgassing epoxy.
- Extreme Thermal Cycling: As the satellite orbits the Earth, it passes in and out of the planet’s shadow, subjecting it to extreme and rapid temperature swings. Components can be exposed to extremely low temperatures, as low as -184°F (–120°C) in low Earth orbit and then rapidly heat to over 248°F (120°C) when exposed to direct solar radiation. This relentless thermal cycling induces significant mechanical stress at the interface between the potting epoxy and the various substrates (ceramic PCBs, metallic housings, glass lenses), which can lead to micro-cracking, delamination, and bond failure.
- Radiation Degradation: The satellite is constantly bombarded with a high flux of solar and cosmic radiation. Over a mission’s multi-year lifespan, this radiation exposure can break down the polymer chains of an unprotected epoxy, causing it to become brittle and lose its essential mechanical and adhesive properties.
- Launch Stresses: The entire assembly must survive the violent shock and high-frequency vibration loads characteristic of a rocket launch without any structural failure or shift in the alignment of its potted components.
Looking for a Low Outgassing Epoxy for Your Aerospace Application?
Our experts at Kohesi Bond can engineer a custom adhesive that meets NASA ASTM E595 standards and your specific mission requirements.
The Kohesi Bond Solution | Custom Engineered Certainty
To overcome this combination of hostile environmental factors, a highly specialised low outgassing epoxy system was required, with performance characteristics tailored specifically for spaceflight applications.
- NASA Low Outgassing (ASTM E595): This is the paramount, non-negotiable requirement. The selected epoxy must be rigorously tested and certified to meet the NASA Low Outgassing standard, ASTM E595. This test, conducted at 125°C in a high vacuum, measures two key parameters: Total Mass Loss (TML), which must be less than 1.0%, and Collected Volatile Condensable Material (CVCM), which must be less than 0.10%. The CVCM value is especially critical as it directly quantifies the material’s propensity to contaminate sensitive surfaces.
- Broad Service Temperature Range: The material must be cryogenically serviceable and maintain its structural integrity and adhesion across the full operational temperature spectrum, from -184°F (–120°C) to 248°F (120°C).
- Low Shrinkage and Low CTE: To ensure the integrity of bonded optical assemblies and prevent stress on electronic components during thermal cycling, the epoxy must exhibit minimal shrinkage upon cure and possess a low Coefficient of Thermal Expansion (CTE) that closely matches that of the substrates it bonds to.
- Radiation Resistance: The polymer chemistry must be inherently robust and resistant to degradation from long-term exposure to the space radiation environment.
- Dimensional Stability and Adhesion: To withstand launch vibrations, the epoxy must form high-strength bonds to a variety of dissimilar aerospace materials, including aluminum, titanium, ceramics, and composites, and maintain its precise shape and dimensions.
To meet the application’s specific requirements, Kohesi Bond’s adhesive experts custom-formulated KB 1039CRLP-AO. This highly specialised, two-component low outgassing epoxy potting compound meets NASA’s ASTM E595 standard, offers a low coefficient of thermal expansion (CTE) and minimal shrinkage, and withstands the extreme thermal, radiation, and vibration loads typical of a space-bound satellite.
Related Products
KB 1039CRLP-AO
Kohesi Bond KB 1039 CRLP-AO is a two component, heat curing epoxy system suitable for bonding, sealing, coating, potting and encapsulation. It has a favorable 100:65 (Part A: Part B) mix ratio by weight. Read More
The Result
The selection of Kohesi Bond’s KB 1039 CRLP-AO low-outgassing epoxy was instrumental in the success of the OEM’s star tracker program. This satellite component epoxy successfully passed all ground-based thermal-vacuum (TVAC) chamber tests, which simulate the vacuum and temperature extremes of space, showing no evidence of optical fogging or material degradation.
This technical validation, underpinned by the ASTM E595 certification, was a critical gate-check that enabled the potted electronics to maintain perfect alignment and functionality, ensuring the operational reliability required during mission lifespan.
Kohesi Bond’s custom-engineered epoxy de-risked the OEM’s mission-critical application.
Ensure Mission Success with Kohesi Bond
Whether it’s satellite components, aerospace electronics, or optical assemblies, our NASA-certified low outgassing epoxies deliver proven results in the most demanding environments. Let’s engineer certainty for your next mission.
Utsav Shah is a 34-year-old entrepreneur with a passion for scientific discovery. Utsav’s journey began with a deep dive into materials science, earning degrees from USC and the Institute of Chemical Technology. He’s the visionary founder of Kohesi Bond, a top-rated adhesive manufacturer, and Cenerge Engineering Solutions, a leader in heat exchangers and cryogenic pumps. With over a decade of experience, Utsav consults across various industries, ensuring they have the perfect adhesive solution for their needs. Connect with him on LinkedIn!
