Control heat flow and radiative balance with ultra-thin, space-qualified coatings engineered for precise emissivity and solar absorptivity control.

Acktar provides fully inorganic, vacuum deposited coatings applied directly to components or supplied as coated foils and films.
These coatings enable controlled emissivity (ε) and solar absorptivity (α) across relevant wavelengths, allowing passive thermal management without adding mass, thickness, or mechanical complexity.

Thermal imbalance is the root problem.
Temperature drift, overheating, and detector instability are symptoms.

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What Problem Does This Solve?

Thermal control in optical, electronic, and space systems is governed primarily by radiative heat exchange rather than convection. Small deviations in emissivity (ε) or solar absorptivity (α) can result in significant temperature instability, performance drift, or premature component failure.

In practical systems, poor thermal control leads to:

Temperature gradients across optical and mechanical structures
Detector noise increase and signal drift
Focus shift and mechanical distortion
Reduced lifetime of sensitive components
Loss of calibration stability

The challenge is amplified in systems with:

Vacuum or space operation
Cryogenic or high-temperature cycling
High solar exposure or internal heat generation
Tight mass, volume, and contamination constraints

In addition to thermal balance, spacecraft surfaces increasingly face requirements related to optical visibility and light pollution mitigation. High reflectance external materials can contribute to satellite brightness, affecting ground-based astronomical observations. Several regulatory bodies and space agencies are introducing guidelines and requirements aimed at reducing satellite reflectivity and limiting orbital light pollution.

Thermal-control blankets and external films therefore serve a dual function:

Radiative heat management through controlled α/ε ratios
Reduction of unintended visible reflectance to mitigate light pollution and support compliance with emerging satellite brightness constraints

Conventional paints, tapes, and polymer based thermal coatings suffer from thickness buildup, aging, cracking, outgassing, and unstable thermo optical properties, making them poorly suited for high reliability applications and long-term orbital exposure.

Acktar’s Approach to Thermal Control

Acktar enables passive thermal control by qualifying radiative properties at the surface level using proprietary vacuum deposition processes. Fully inorganic coatings are deposited with controlled composition and morphology to deliver stable, predictable emissivity and absorptivity values.

Key characteristics:

Precisely controlled emissivity (ε) and solar absorptivity (α)
Stable thermo-optical properties across wide temperature ranges
Uniform performance over large areas and complex geometries
No cracking, flaking, or aging under thermal cycling

Coatings are typically <5 µm thick, preserving mechanical tolerances and allowing integration on precision parts, thin films, and flexible substrates. All solutions are qualified for low outgassing and long-term operation in vacuum, thermal vacuum, cryogenic, and space environments.

Implementation Approaches

Acktar supports two complementary thermal-control implementation paths:

Direct Coating on Components – Thermal-control coatings are applied directly to customer parts with selective masking, enabling localized control of emissivity and absorptivity without affecting functional interfaces.

Thermal Management Foils and Films – Acktar supplies pre-coated foils and films designed for integration as outer layers in MLI (Multi Layer Insulation) or SLI (Single Layer Insulation), as well as for internal thermal balancing.

Heat Retention / Solar Absorption

Coating / Product Family	Form Factor	Solar Absorptivity (α)	Emissivity (ε)	Typical Use Cases
Nano Black™	Foils / Films	> 0.92	< 0.17	Solar absorbers, passive heating elements, thermal biasing surfaces, structures requiring high α/low ε ratio

Heat Rejection / Radiative Cooling

Coating / Product Family	Form Factor	Solar Absorptivity (α)	Emissivity (ε)	Typical Use Cases
Ultra White™	Foils / Films	< 0.23	> 0.85	Space radiators, external spacecraft panels, high solar exposure surfaces
White Standard™	Foils / Films	< 0.40	> 0.70	Balanced thermal control surfaces, MLI/SLI outer layers, moderate radiator applications

Near Blackbody / Maximum Absorption & Emission

Coating / Product Family	Form Factor	Solar Absorptivity (α)	Emissivity (ε)	Typical Use Cases
Maxi Black™	Foils / Films	> 0.95	> 0.85	High emissivity radiators, internal heat rejection, thermal uniformity surfaces
Metal Velvet™ (Spectral Black)	Aluminum Foil (Single/Double Sided)	Broadband High (UV–IR)	High Broadband IR	Nea blackbody behavior, combined optical + thermal absorption, cavity absorption, internal thermal control
Customized Thermal Coatings	Direct Coating or Foils	0.05–0.7	0.03–0.9	Application specific α/ε tuning, precision radiative balance control

Technical Performance

Thermo optical tuning: engineered control of solar absorptivity (α) from 0.05 to >0.95 and emissivity (ε) from 0.03 to >0.93, product dependent
Emissivity range (2–20 µm): up to >0.93, product dependent
Solar absorptivity (AM0): from <0.23 (radiative cooling surfaces) to >0.95 (solar absorbing surfaces), product dependent
Coating thickness: typically <5 µm
Thermal stability: cryogenic conditions down to −196°C (product dependent down to 4 K in specific configurations) up to +350°C continuous; certain foil configurations support short term exposure up to +400°C, and copper-based variants up to +450°C without adhesive
Environmental compatibility: vacuum, thermal vacuum, cryogenic environments, atomic oxygen exposure (product dependent)
Outgassing: fully inorganic coating; CVCM <0.001% (product dependent), compliant with space and vacuum requirements

All thermal control products are qualified through controlled thermal cycling, thermal-vacuum cycling, cryogenic exposure, adhesion verification per tape test standards, and post environmental verification of hemispherical reflectance, solar absorptivity, and infrared emissivity stability.

Applications

Passive thermal control of space structures and payloads
Radiators and heat rejection surfaces
Optical benches and detector housings
Multi-layer insulation (MLI) and single layer insulation (SLI)
Satellite external and internal thermal surfaces
Cryogenic instruments and vacuum systems
Precision instruments requiring thermal stability
Semiconductor wafer chucks and electrostatic chucks (ESC)
Wafer handling, inspection, and metrology stages
Component mounting platforms for optical and electronic testing
laser systems and beam dumps

Integration & Compatibility

Substrates: Polyimide (Kapton® type films), aluminum, titanium, stainless steel, copper, Invar, Kovar, tungsten, molybdenum, nickel, ceramics, glass, and composite materials used in space structures and insulation blankets. Substrate suitability is defined by thermal limits, surface finish, and preparation requirements.
Formats: Direct coating on precision parts; coated foils, films, sheets, rolls, tapes, and tight-tolerance die-cuts. Optional low outgassing adhesive configurations available for foil and film integration.
Geometries: Flat surfaces, complex curved structures, thin walled components, flexible assemblies, selectively masked regions, and patterned areas requiring defined coated/uncoated boundaries.
Manufacturing Routes: Customer furnished parts for direct coating; supply of pre coated foils and films: or turnkey manufacture and coating of patterned components according to drawing and specification.
Cleanliness: Cleanroom compatible handling, processing, and packaging to support contamination controlled environments. Cleanliness levels aligned to application requirements.
Outgassing: Fully inorganic coatings qualified for vacuum and space environments. Low CVCM and RML performance available per product configuration, supporting space grade and high reliability systems.

Mission-Proven Results

Acktar thermal control coatings are deployed in operational space and high reliability systems, delivering stable temperature control, reduced thermal gradients, and long term thermo optical stability across mission lifetimes.