# Carbon Nanocomposites in Aerospace Technology: A Way to Protect Low-Orbit Satellites
## 2 Corrosion Factors and Mechanisms in Low Orbit Environment
### Lab-Based AO Corrosion Experiments and Facilities  
It should be noted that, to some extent, both simulated and in-flight corrosion experiments can be either not very reliable, or very expensive ways to optimize the corrosion behavior and decrease the impact of corrosion on space assets. In contrast, when properly designed, relevant experiments in conventional laboratories dealing with material science would be of great help when it comes to collecting large volumes of potentially valuable \begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Material** & **Polymer** & **MISSE 2** & **Density. g/cm\({}^{3}\)** & **Area, cm\({}^{2}\)** & **MISSE 2** \\  & **Abbreviation** & **Mass Loss, g** & **Density. g/cm\({}^{3}\)** & **Area, cm\({}^{2}\)** & **Erosion Yield, cm\({}^{3}\)/atom** \\ \hline Polyamide 6 or nylon 6 & PA 6 & 0.118376 & 1.1233 & 3.5646 & 3.51 \(\times\) 10\({}^{-24}\) \\ \hline Polyamide 66 or nylon 66 & PA 66 & 0.065562 & 1.2252 & 3.5249 & 1.80 \(\times\) 10\({}^{-24}\) \\ \hline Polyimide & PI (CP1) & 0.080648 & 1.4193 & 3.5316 & 1.91 \(\times\) 10\({}^{-24}\) \\ \hline Polyimide (PMDA) & PI (Kapton H) & 0.124780 & 1.4273 & 3.4590 & 3.00 \(\times\) 10\({}^{-24}\) \\ \hline Polyimide (PMDA) & PI (Kapton HN) & 0.121315 & 1.4346 & 3.5676 & 2.81 \(\times\) 10\({}^{-24}\) \\ \hline Polyimide (BPDA) & PI (Upilex-S) & 0.038127 & 1.3866 & 3.5382 & 9.22 \(\times\) 10\({}^{-25}\) \\ \hline Polyimide (PMDA) & PI (Kapton H) & 0.129250 & 1.4273 & 3.5773 & 3.00 \(\times\) 10\({}^{-24}\) \\ \hline High temperature polyimide resin & PI (PMR-15) & 0.118887 & 1.3232 & 3.5256 & \(>\)3.02 \(\times\) 10\({}^{-24}\) \\ \hline Polybenzimidazole & PBI & 0.082708 & 1.2758 & 3.4762 & \(>\)2.21 \(\times\) 10\({}^{-24}\) \\ \hline Polycarbonate & PC & 0.142287 & 1.1231 & 3.5010 & 4.29 \(\times\) 10\({}^{-24}\) \\ \hline Polyethertherkeytone & PEEK & 0.107764 & 1.2259 & 3.4821 & 2.99 \(\times\) 10\({}^{-24}\) \\ \hline Polyethylene terephthalate & PET (Mylar) & 0.125187 & 1.3925 & 3.5432 & 3.01 \(\times\) 10\({}^{-24}\) \\ \hline Chlorotrifluoroethylene & CTFE (Kel-f) & 0.052949 & 2.1327 & 3.5452 & 8.31 \(\times\) 10\({}^{-25}\) \\ \hline Ethylene-chlorotrifluoroethylene & ECTFE (Halar) & 0.088869 & 1.6761 & 3.5103 & 1.79 \(\times\) 10\({}^{-24}\) \\ \hline Tetafluorethylene-ethylene copolymer & ETFE (Tefzel) & 0.049108 & 1.7397 & 3.4854 & 9.61 \(\times\) 10\({}^{-25}\) \\ \hline Fluorinated ethylene propylene & FEP & 0.012479 & 2.1443 & 3.4468 & 2.00 \(\times\) 10\({}^{-25}\) \\ \hline Polytetrafluoroethylene & PTFE & 0.008938 & 2.1503 & 3.4841 & 1.42 \(\times\) 10\({}^{-25}\) \\ \hline Perfluoroalkoxy copolymer resin & PFA & 0.010785 & 2.1383 & 3.4570 & 1.73 \(\times\) 10\({}^{-25}\) \\ \hline Amorphous Fluoropolymer & AF & 0.012352 & 2.1463 & 3.4544 & 1.98 \(\times\) 10\({}^{-25}\) \\ \hline Polyvinylidene fluoride & PVDF (Kynar) & 0.066860 & 1.7623 & 3.4993 & 1.29 \(\times\) 10\({}^{-24}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: \(Cont.\)  
Figure 6: In-orbit material experiment project. Based on a 2U (double-unit) CubeSat, this system incorporates several material experiments, namely CiREX (Carbon Nanotubes—Resistance Experiment), Flux-(Phi)-Probe-Experiment (FIPEX) and Thermoelectric-Generator-Experiment (TEG). Reprinted with permission from [PERSON] et al., 2019 [PERSON] et al., 2019 [PERSON] et al., 2019 [PERSON] et al., 2018 COSPAR. Published by Elsevier. experimental data on space-related corrosion, while providing a more rapid path to optimization and innovation. Indeed, LEO degradation and erosion are simulated in ground laboratories using a variety of experimental facilities, each with their own limitations. These include exposure to RF plasma, low-energy ion neutralization, electron-stimulated desorption, photodissociation, supersonic and laser detonation sources [44]. Currently, extensive efforts are applied to develop more sophisticated, well-equipped ground-based test facilities for comprehensive testing of space-intended materials under the conditions specific to LEO and VLEO orbits.