Microporous insulation is a type of thermal insulation that consists of tiny pores filled with air or inert gas. These pores reduce the heat transfer by conduction, convection, and radiation, making microporous insulation an ideal material for high-temperature applications. The global microporous insulation market size reached a value of about USD 168.15 million in 2023, driven by the increasing demand from various industries, especially the aerospace industry.
The aerospace industry is one of the major consumers of microporous insulation, as it requires efficient thermal management for the safety and performance of its vehicles and systems. In this blog post, we will explore some of the applications of microporous insulation in the aerospace industry, such as thermal protection systems, cryogenic applications, insulation for avionics and electronics, and future trends and innovations.
Thermal Protection Systems (TPS)
Thermal protection systems (TPS) are designed to protect spacecraft and aircraft from the extreme heat generated during atmospheric re-entry and high-speed flight. TPS can be classified into two types: passive and active. Passive TPS rely on the insulation material to absorb and dissipate the heat, while active TPS use cooling fluids or mechanisms to regulate the temperature.
Microporous insulation is widely used as a passive TPS material, as it offers excellent heat shielding capabilities. Microporous insulation can withstand temperatures up to 1000°C and has a low thermal conductivity of 0.02 W/mK. Moreover, microporous insulation is lightweight and flexible, which reduces the mass and drag of the vehicle.
Some examples of microporous insulation in TPS are:
- NASA's Orion spacecraft, which uses microporous insulation tiles to protect the crew module from the re-entry heat of up to 2800°C.
- The European Space Agency's (ESA) IXV re-entry demonstrator, which uses microporous insulation blankets to cover the vehicle's surface and provide thermal protection.
- The Boeing X-51A WaveRider, which is a hypersonic aircraft that uses microporous insulation panels to shield the engine and the fuselage from the aerodynamic heating of up to 980°C.
Cryogenic Applications
Cryogenics is the science of low-temperature phenomena and applications. Cryogenic applications in the aerospace industry involve the storage and transportation of propellants and gases at very low temperatures, such as liquid hydrogen, liquid oxygen, liquid nitrogen, and helium. These substances are used for various purposes, such as rocket propulsion, superconducting devices, and cooling systems.
Microporous insulation is an ideal material for cryogenic applications, as it can maintain the low temperatures and prevent heat loss. Microporous insulation has a very low thermal conductivity at cryogenic temperatures, ranging from 0.004 to 0.008 W/mK. Additionally, microporous insulation is resistant to moisture and gas permeation, which enhances its durability and reliability.
Some examples of cryogenic applications of microporous insulation in aerospace are:
- The SpaceX Falcon 9 rocket, which uses microporous insulation to insulate the liquid oxygen and liquid kerosene tanks.
- The ESA's CryoSat-2 satellite, which uses microporous insulation to protect the superconducting magnetometer from the thermal fluctuations in space.
- The NASA's James Webb Space Telescope, which uses microporous insulation to cool the infrared detectors to 7 K.
Insulation for Avionics and Electronics
Avionics and electronics are the systems and components that provide navigation, communication, control, and data processing for aerospace vehicles and devices. These systems and components are sensitive to temperature variations and require thermal insulation to ensure their optimal functioning and longevity.
Microporous insulation is a suitable material for insulating avionics and electronics, as it can protect them from the high and low temperatures encountered in the aerospace environment. Microporous insulation can also reduce the thermal expansion and contraction of the electronic components, which can cause mechanical stress and damage. Furthermore, microporous insulation is non-combustible and non-toxic, which enhances the safety and environmental friendliness of the material.
Some examples of microporous insulation in avionics and electronics are:
- The ESA's Rosetta spacecraft, which uses microporous insulation to insulate the onboard computer and the power supply unit.
- The NASA's Mars 2020 rover, which uses microporous insulation to insulate the radioisotope thermoelectric generator and the battery.
- The Airbus A350 XWB, which uses microporous insulation to insulate the cockpit and the cabin.
Future Trends and Innovations
The aerospace industry is constantly evolving and innovating, and so is the microporous insulation technology. There are several ongoing research and development projects that aim to improve the performance and cost-effectiveness of microporous insulation for aerospace applications. Some of the potential advancements in microporous insulation technology are:
- The development of novel microporous materials, such as silica aerogels, carbon nanotubes, and graphene, that can offer higher thermal resistance and lower density than the conventional microporous materials.
- The optimization of the manufacturing processes and the design of the microporous insulation products, such as using additive manufacturing, vacuum forming, and composite structures, to reduce the material and labor costs and increase the production efficiency.
- The integration of microporous insulation with other materials and technologies, such as phase change materials, thermoelectric devices, and smart sensors, to create multifunctional and adaptive thermal insulation systems.
These innovations can have a significant impact on the design and efficiency of future aerospace vehicles, such as reusable launch vehicles, hypersonic aircraft, and interplanetary spacecraft.
