A review on the advances achieved in the last 25 years in the development of hybrid nanocomposites based on polymer matrix for aerospace applications is presented here. The chapter analyzes the state-of-the-art strategies used in the design of materials that support the different conditions of the space environment. These materials are aimed primarily at structural applications, electromagnetic interference shielding, self-sensing, and self-healing, although they are not restricted to these applications. The introduction of metallic, ceramic, carbon-based nanomaterials such as carbon nanotubes and graphene, as well as two-dimensional materials have been used with a successful impact. Despite the significant advances that have been reached, much work must be done to achieve complete reliability for all properties required to protect the systems against the hazardous conditions found in space. Therefore, futuristic visions of the actions that must be carried out are raised in this chapter.
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Despite the technological advances achieved so far, scientists around the world are still looking for alternative materials that survive the conditions in space (Aïssa, 2019). Materials in space experience extreme conditions that are not found on Earth such as temperature, gravity, radiation, pressure, etc. The temperature in space ranges from -101 to 208 °C and during re-entry, the friction of the atmosphere will generate heat around the spacecraft up to 2760 °C. During the launch of spacecraft, they will experience up to three times the force of the Earth's gravity, and materials should not break, bend or weaken under such effects (Cander, 2019). Once the spacecraft reaches orbit, the force of gravity drops to almost zero, so this drastic change can affect the integrity of low-grade materials or those that do not support such efforts. In addition to this, materials in space are subject to radiation levels directly proportional to the height at which the space system orbits the planet. Therefore, these are regularly designed to operate in the low-earth orbit to experience less radiation than those operating in higher orbits or destined for even farther trips. Solar storms dramatically increase radiation levels without warning (Malandraki, 2018). Also, the materials in the spacecraft must withstand internal and external pressures, the first due to oxygen pressure of up to 15 pounds per square inch and the second due to gravitational changes. Due to the large amount of space debris produced by deceased satellites, spacecraft are exposed to impacts that can cause significant damage to their structure, so materials must be robust to withstand these events. The spontaneous presence of meteors with faster speeds than bullets (42 kilometers per second) can produce a hole in the weak parts of the structure. Finally, mechanical vibrations in a very wide range of frequencies must be avoided or minimized during and immediately after launch, so spacecraft materials should not present structural weaknesses. Therefore, each of the devices, systems or structures used in space must withstand similar conditions with varying levels of performance (Belous, 2017).
The materials that have been successfully used in the space environment are Kevlar (resistance to meteor and space debris impacts, durability, withstands extreme temperatures without damaging its structure or changing its shape), aluminum alloys (strength, light weight, resistance on impact), reinforced carbon-carbon composite coated with silicon carbide (withstands temperatures greater than 1260 °C), borosilicate glass (high and low temperature surface insulations), Nomex felt (surface insulation for temperatures below 371 °C in the middle and tail end), thermal glass (windows), silica (launch gears or loading site, low temperature zones), and sodium silicate (sealing of cracks). The use of polymer matrix nanocomposites allows the creation of optimal multifunctional materials for aerospace needs and applications (Rathod, 2017). Fillers used in this type of composite materials introduce new physical properties that polymers do not possess, resulting in high performance materials. The introduction of nanomaterials has led to improved capabilities by exploiting their mechanical, field emission, thermal, electrical and optical properties in aerospace design and applications. Future space missions require lightweight materials that maintain their physical properties for more than 30 years in hazardous environments such as exposure to atomic oxygen and solar radiation.