Internationally Qualified Sensors: For nearly five decades, TE has supplied temperature sensors to NASA and ESA, adhering to stringent GSFC (Goddard Space Flight Center) S-311-P-18 standards required by NASA as well as ESA’s requirements.

Proven performance: Our sensors were included in historic space missions such as Pioneer 10 spacecraft launched in 1972 and the 2011 Juno mission to Jupiter, as well as many other exploratory missions. Our deep experience and commitment to innovation confirm our temperature sensors meet the rigorous demands of space missions, providing reliable performance and contributing to the success of various aerospace projects.

Temperature sensors are critical components in all types of spacecraft. Monitoring internal and external temperatures, they provide data essential to the vessel’s reliability, safety and efficiency. These instruments play key roles such as:

Managing thermal variations is both a critical application for temperature sensors and a significant challenge for implementation. Spacecraft experience extreme temperature swings from -270°C to +250°C depending on which side is facing the sun. These extreme temperatures can affect the functionality and performance of many components throughout the vessel, so it is important to implement thermal management to limit exposure of the sensors to extreme thermal cycling. Designers must select sensors designed to withstand the expected temperature ranges at the sensors while considering equipment failures that may lead to excursions.

Unique thermal conditions require thoughtful consideration when applying temperature sensors in spacecraft. Radiant and conductive transmission modes replace convection as the primary mode of heat transfer due to the absence of an atmosphere. This can lead to uneven temperatures that impact the sensor’s accuracy. Therefore, engineers must locate sensors strategically to compensate and choose appropriate sensor materials, mounting hardware and methods. Using active thermal control, such as heaters and coolers, will help to maintain the best operating conditions.

The presence of gamma ray, proton and heavy ion radiation can cause degradation of the materials used in instruments and sensors causing inaccurate readings. These errors can compromise the operation and safety of the satellite.

To address this challenge, specify radiation-hardened temperature sensors and include robust materials such as in the sensor design. Utilize redundant sensors along with periodic autocalibration and consider algorithms to compensate for radiation-induced errors.

Spacecraft experience vibration and shock that can affect temperature sensors, during launch, orbital maneuvers and re-entry. Thermal cycling may also introduce stress in sensors. These stresses may cause the accuracy of temperature sensors to drift if materials are not specified. Where possible, mount discreet sensors in robust enclosure or use a full probe assembly to protect from shocks and vibrations and/or include flexible mounting techniques. Employing calibration and compensation algorithms can also address accuracy. Also, redundant sensors provide a backup to signal issues with readings.

Vacuum conditions and high temperatures can cause materials to emit volatile compounds which coat surfaces. Over time, these coatings can significantly affect operation of other onboard equipment. To prevent this issue, materials designed to minimize outgassing should be used throughout the spacecraft. Where material changes are not feasible, employ space-grade coatings to prevent this issue. Performing a thermal vacuum bakeout of components and materials prior to installation also helps to prevent this issue.

Spacecraft have limited power budgets due to the size and efficiency of their solar panels and the capacity of their battery systems. Sensors that require continuous power for operation can reduce the power available for other systems. To reduce power demands, utilize low power sensors like thermistors or RTDs where possible. Implement smart power management to prioritize allocation. Optimize insulation to reduce active thermal management requirements.

Selecting temperature sensors for spaceflight requires careful consideration of the extreme thermal environments spacecraft encounter. During launch, temperatures range from -40°C to +250°C. In Low Earth Orbit (LEO), they can vary between -100°C and +250°C. Deep space temperatures can drop to nearly absolute zero (-270°C), while atmospheric re-entry can expose spacecraft to over 1,650°C. This section explores the criteria for choosing NTC thermistors and platinum RTDs, with examples of their applications. Experienced sensor suppliers can provide valuable insights and access to sensors that have been rigorously tested for specific conditions, however the following provides general information about selection criteria.

Selecting temperature sensors for spaceflight requires careful consideration of the extreme thermal environments spacecraft encounter. During launch, temperatures range from -40°C to +250°C. In Low Earth Orbit (LEO), they can vary between -100°C and +250°C. Deep space temperatures can drop to nearly absolute zero (-270°C), while atmospheric re-entry can expose spacecraft to over 1,650°C.

This section explores the criteria for choosing NTC thermistors and platinum RTDs, with examples of their applications. Experienced sensor suppliers can provide valuable insights and access to sensors that have been rigorously tested for specific conditions, however the following provides general information about selection criteria.

Locate thermistors as close as possible to the critical components being monitored to confirm accurate readings of solar arrays, batteries, electronics, and propulsion system components. Use thermally conductive (minimal outgassing) adhesives or mechanical fasteners that can withstand the expected conditions including shock vibrations and temperature fluctuations. Ensure good thermal contact between the thermistor and the surface being measured. Where possible, use thermal grease compatible with the environment (minimal outgassing) to improve conductive heat transfer. Protect thermistors from radiation and electromagnetic interference (EMI) with shielding materials or by placing them in a shielded enclosure.

For high-temperature environments, use RTDs specifically designed to withstand extreme temperatures. Implement thermal bridges or insulation to reduce exposure of RTDs to high temperatures while providing accurate measurements. Regular calibration is crucial to prevent sensor drift. Automatic calibration software routines should be considered for long-duration missions. Install multiple RTDs in critical areas to provide redundancy.

Choose a sensor provider with a proven record of supplying sensors for space missions. Thorough testing including thermal cycling, shock, vibration, outgassing and radiation exposure testing are critical to confirm that sensor designs are space qualified before integration. Integrate the sensor data into the spacecraft’s thermal management system for real-time monitoring and control. Maintain detailed documentation of sensor placement, calibration procedures and testing results for troubleshooting and reference on future missions.

Objective: Long-term Earth observation for monitoring land use, deforestation, urbanization and natural disasters. Managed by NASA and USGS, the Landsat series has been providing continuous data since 1972.

NTC Thermistor applications in Landsat 8 (2013) and 9 (2021): NTC thermistors are integrated into the thermal control systems to monitor and regulate the temperature of the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). Both instruments require precise temperature management to collect high quality data. Engineers designed these thermistors to operate reliably in harsh space conditions including exposure to radiation, vacuum and extreme temperature fluctuations.

Objective: Providing high-precision global navigation services. Operated by ESA, Galileo offers accurate positioning and timing services for civilian and commercial use. The first satellites in this mission were launched in 2005 with 30 satellites in the current constellation.

NTC thermistors are embedded in the solar arrays of these satellites, protecting the photovoltaic cells from overheating while also providing feedback for performance optimization. Platinum RTDs are essential for maintaining the precise temperature control required for accurate atomic clock operation. These clocks provide highly accurate global positioning and timing.

Objective: Observing astronomical phenomena and deep space. Joint NASA and ESA mission, Hubble has provided groundbreaking data on the universe since 1990.

A combination of NASA qualified NTC thermistors and strain gauges monitor the structural health of the Hubble Space Telescope. Detecting rapid temperature changes along with material deformation, these sensors collaborate to quickly trigger mitigations to confirm the structural integrity of the satellite. In the three decades between this mission and the newer James Webb Space Telescope, the structural health monitors saw new developments in temperature sensors that improved sensitivity and range as well as enhanced durability and reliability.