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Mirror substrates for satellites

Mirror substrates for satellites

Satellites are the eyes and instruments of our modern world. From monitoring Earth’s climate to exploring distant planets, they deliver critical data with pinpoint accuracy. Yet, achieving this precision in the harsh environment of space is one of engineering’s greatest challenges. In orbit, temperatures can swing from −150 °C to +150 °C, mechanical loads during launch are extreme, and there’s no room for adjustment once deployed. Optical instruments aboard satellites must remain perfectly aligned over years of operation — despite constant thermal cycling, vacuum conditions, and radiation exposure. To succeed, designers rely on materials that combine dimensional stability, optical quality, and flight heritage.

Understanding the challenges in satellite design

Thermal stability

Temperature fluctuations in orbit can distort conventional materials. Even microns of expansion or contraction can cause defocus, blurring images or misaligning instruments.

Optical precision

High-resolution imagers and telescopes demand ultra stable materials that preserve geometry with extreme precision. Once in orbit, mirrors must maintain exact curvature to ensure mission performance.

Lightweight and rigid

Every kilogram launched into space matters. Components must be lightweight yet stiff and homogeneous in material quality, ensuring they can survive launch and maintain precision during operation.

Radiation and longevity

Satellites are exposed to cosmic irradiationand charged particles for years. Materials must resist radiation damage and maintain performance over long mission durations.

Alignment stability

Telescopes and Instruments like interferometers, spectrometers, or laser terminals depend on stable alignment. Tiny shifts can break optical paths and compromise data quality.

Where precision matters most: Satellite applications

Earth observation and meteorology

From mapping terrain to monitoring weather patterns, Earth observation satellites rely on ultra-stable optical systems. Missions such as SPOT, PLEIADES, CARTOSAT, KOMPSAT, GOES, and METEOSAT use stable mirror substrates to deliver sharp, repeatable images for decades.

Astronomy and space science

In space telescopes and observatories like Hubble, CHANDRA, COROT, and CHEOPS, maintaining optical alignment and figure stability is essential for capturing distant light with accuracy.

Laser communications and technology demonstrators

Laser-based data links and experimental payloads — such as SILEX on ARTEMIS — depend on thermally invariant optical benches for reliable beam pointing and interferometry.

Solar and planetary science

Missions studying the Sun or other planets, like Solar Orbiter, SOHO, and the Mars Reconnaissance Orbiter, face extreme thermal gradients. Only materials with near-zero expansion ensure lasting precision. From low Earth orbit to deep-space missions, SCHOTT’s materials have flown on over 100 satellites worldwide.

Partnering with satellite designers

At SCHOTT, we don’t just deliver materials — we collaborate with engineers to design optical and structural components that meet the most demanding specifications. Our support spans from material selection and machining to lightweighting, high precision grinding, and metrology.
We’ve partnered with leading agencies and system integrators — including ESA, NASA, CNES, ISRO, and JAXA — to build flight-proven solutions across decades of missions.

Our mission: To help yours succeed — with materials that ensure precision, reliability, and stability in orbit.

Detailed view of ZERODUR composite structure

ZERODUR®: Enabling stable optics in space

Mean coefficient of linear thermal expansion

ZERODUR® glass-ceramic is supplied with a mean coefficient of linear thermal expansion (CTE) in the temperature range 0°C to 50°C in six expansion classes as follows:

CTE (0°C; 50°C) specification tolerances
Expansion Class 2	0 ± 0.100 ppm/K
Expansion Class 1	0 ± 0.050 ppm/K
Expansion Class 0	0 ± 0.020 ppm/K
Expansion Class 0 Special	0 ± 0.010 ppm/K
Expansion Class 0 Extreme	0 ± 0.007 ppm/K
CTE optimized for application temperature profiles
ZERODUR® TAILORED	0 ± 0.020 ppm/K (± 0.010 ppm/K upon request)

When thermal expansion is not an option, ZERODUR® delivers. With an near-zero coefficient of thermal expansion (CTE), exceptional homogeneity, and radiation resistance, it’s the reference material for space optics.

Design challenge	ZERODUR® solution
Thermal distortion	Near-zero CTE maintains shape under temperature swings
Alignment drift	Dimensional stability ensures long-term optical precision
Surface quality	Excellent polishability for nanometer-level surfaces
Weight constraints	Available in customized lightweighted configurations
Harsh environment	Proven radiation and vacuum stability

Learn more about the material properties on the ZERODUR® product page →

Space-proven heritage

For over 40 years, ZERODUR® has been part of flagship satellite missions across multiple disciplines:

Earth observation

SPOT, PLEIADES, METEOSAT, GOES, LANDSAT, CARTOSAT

Science and astrometry

Hubble, CHANDRA, CHEOPS, HIPPARCOS

Laser communication

ARTEMIS/SILEX

Solar and planetary missions

FAQs

What materials are used for satellite mirrors?

Satellite mirrors often use glass-ceramics like ZERODUR® for their near-zero thermal expansion and high optical quality.

Why is thermal stability important in space?

In orbit, temperature swings can cause ordinary materials to expand or contract, distorting optics and misaligning instruments. Thermally stable materials prevent this.

What makes ZERODUR® suitable for satellites?

Its ultra-low CTE, radiation resistance, and long flight heritage make it ideal for high-precision optical systems in space

Want to know more? Let’s talk

Whether you need more information, samples, a quote, or advice for a project, we would be delighted to talk to you.

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Mirror substrates for satellites