Atomic Oxygen Environment Research Articles

Reliability of micro-resistance welded dissimilar connection between Ag-plated Kovar foil and GaAs space solar cell: Processing, microstructure and bonding strength

Solar panels in low earth orbit (LEO) can suffer from damage caused by atomic oxygen (AO) exposure and thermal shock, which may shorten the service life of their interconnectors and joints. Ag-plated Kovar foil has emerged as a promising material for interconnecting solar cell arrays. This study uses parallel gap resistance welding (PGRW) to conduct ultrafast Ag-plated Kovar foil and solar cell bonding in just 190 ms. The bonding strength depends on the current densities, with a diffused interface observed at a density of 475 A/mm2. The EBSD results show that grains of Ag layer and Au layer grow at the central bonding interface, whereas grains of Ag layer and Au layer form a weakened bonded line at the edge bonding interface. The thermal reliability of joints with Ag-plated Kovar foil is better than traditional Ag foil, with no decline in tensile-shear force observed even after multiple thermal cycles. Although the Ag layer of Kovar foil oxidizes as AgO and Ag2O in an AO environment, the joining interface remains unaffected. This investigation into PGRW joints of Ag-plated Kovar foil is critical for enhancing the high reliability of solar arrays in harsh temperatures and AO space environments.

Influences of temperature on the property of ITO/Teflon/Ag in atomic oxygen environment

This paper uses ground simulation equipment for an atomic oxygen environment to conduct experimental research on ITO/Teflon/Ag, which is used in spacecraft using an atomic oxygen environment. The atomic oxygen integrated flux selected in the study is 9.1× 1019 atoms/cm2, with a vacuum degree of 10-2 Pa, and sample temperatures of 20°C, 70°C, and 120°C, respectively, were selected to investigate the possible impact of sample temperature on atomic oxygen environment simulation experiments. After the test, a high-precision microelectronic balance was used to test the mass loss of the sample and calculate the reaction rate of the material. The thermal emissivity and solar absorption ratio of the sample were tested using TEMP 2000A and LPSR 300, respectively. Through experiments and analysis, it was found that as the sample temperature increased, the ITO/Teflon/Ag reaction rate with atomic oxygen gradually increased but remained at 10-25. Atomic oxygen and temperature have a significant impact on the thermal physical properties of the material.

Effect of Irradiation Dose on the Structure and Tribological Performance of Ti:WS2/PFPE Composite Lubricating System in Atomic Oxygen Environment

Perfluoropolyether (PFPE) oil possessing higher oxidation stability than hydrocarbon lubricant is combined with Ti:WS2 film to construct a solid–liquid composite lubricating system. The results indicate that atomic oxygen (AO) irradiation generates some important effects for the Ti:WS2/PFPE composite lubricating system. With an increase of irradiation dose, the molecular structure of PFPE oil experiences carbon chain breakage and appears to be an obvious molecule for cross-linking and polymerization. Meanwhile, Ti:WS2 film also is oxidized to a different extent to form WO3. The changes in the solid–liquid system resulted in greatly different tribological properties of the Ti:WS2/PFPE system. The friction coefficient of the system significantly increases with low-dose irradiation, while inversely, the value sharply decreases with high-dose AO, which is related to the presence of WO3 and formation of a transfer film. Finally, the failure mechanism of Ti:WS2/PFPE system under AO irradiation has been revealed.

Exploring the effect of V doping on the tribological mechanism of MoS2 coatings in atomic oxygen environment

MoS2 coatings are subject to severe oxidation and erosion under atomic oxygen (AO) irradiation due to its loose microstructure. This concern can be alleviated by means of metal doping. In this work, MoS2 coatings with different V doping content are deposited by magnetron sputtering. The morphology, chemical stability and tribological properties are investigated by scanning electron microscopy, energy dispersive spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, film stress tester and ball-on-disk tribometer, respectively. As the V doping content increases, the MoS2-V coating changes from a loose columnar crystal structure to a more dense structure. Friction and wear results show that the MoS2-V coating deposited at V target current of 0.5 A owns the best tribological properties with a friction coefficient of 0.04 and wear rate of 1.29 × 10−6 mm3/N·m under simulated AO environment. The objective is to develop MoS2-V composite coatings to AO irradiation resistance in order to select suitable lubricant for reliable space applications.

Erosion evolution and mass loss of polyimide in AO environment using 3D Monte Carlo method

Polyimide films coated on the surface of satellites are exposed to atomic oxygen (AO) environment during service. This will suffer variation of microscopic structure and morphology, leading to corrosion and mass loss in macroscopic. In this work, a 3D undercutting model based on Monte Carlo method (MC) and Ray Tracing method was constructed, with which the AO related erosion feature of polyimide film was evaluated. Then, we predicted the evolution of erosion cross-section of the coated material with defect of different sizes and shapes exposed in higher AO fluence. The macroscopic mass loss was derived by the eroded microscopic volume and material density, during which the actual roughness was considered in our proposed undercutting model. This work provides insights into the study of microscopic 3D erosion morphology and connects with macroscopic mass loss in experiment at higher fluences.

Research of the Property Changes of ITO/Kapton/Al Based on Different Temperature in Atomic Oxygen Environment

In the field of spacecraft space environment engineering, the impact of atomic oxygen on the performance of spacecraft is very critical. According to the relevant literature, temperature is an important factor affecting atomic oxygen. This paper is about atomic oxygen erosion influence on ITO/Kapton/Al based on different temperatures. The temperatures selected were 25 °C, 75 °C, 100 °C, 125 °C, and 150 °C respectively to research the possible influences of different temperatures on atomic oxygen simulation experiment effects. The ground simulation equipment releases a fluence of 9.0×1019 atoms/cm2 under a 10−2Pa vacuum. The mass of samples was measured by high-precision micro-electron balance before and after the experiment and the reaction ratio was calculated. Emissivity and solar absorbance were measured by the TEMP 2000A portable emissivity testing apparatus and LRSR 300 portable spectrum solar absorbance testing apparatus respectively. According to the experiment, it is shown that the ITO protects the base material well, and the mass loss and the reaction ratio of samples show inactive. Results also show that the effects on mass loss are little, but effects on the physical property changes are great by the temperature variation.

Research on Atomic Oxygen Erosion Influence of Structural Damage and Tribological Properties of Mo/MoS2-Pb-PbS Thin Film.

To investigate atomic oxygen effects on tribological properties of Mo/MoS2-Pb-PbS film and further enlarge application range, atomic oxygen exposure tests were carried out for 5 h, 10 h, 15 h, and 20 h by the atomic oxygen simulator with atomic oxygen flux of 2.5 × 1015 atoms/cm2·s. The exposure time in test was equivalent to the atomic oxygen cumulative flux for 159.25 h, 318.5 h, 477.75 h, and 637 h at the height of 400 km in space. Then, the vacuum friction test of Mo/MoS2-Pb-PbS thin film was performed under the 6 N load and 100 r/min. By SEM, TEM, and XPS analysis of the surface of the film after atomic oxygen erosion, it was observed that atomic oxygen could cause serious oxidation on the surface of Mo/MoS2-Pb-PbS film, and the contents of MoS2, PbS, and Pb, which were lubricating components, were significantly reduced, and oxides were generated. From AES analysis and the variation in the main element content, Mo/MoS2-Pb-PbS thin film showed self-protection ability in an atomic oxygen environment. Hard oxide generated after atomic oxygen erosion such as MoO3 and Pb3O4 could cause the friction coefficient slight fluctuations, but the average friction coefficient was in a stable state.

Preparation and Characterization of Transparent Polyimide Nanocomposite Films with Potential Applications as Spacecraft Antenna Substrates with Low Dielectric Features and Good Sustainability in Atomic-Oxygen Environments

Optically transparent polyimide (PI) films with good dielectric properties and long-term sustainability in atomic-oxygen (AO) environments have been highly desired as antenna substrates in low earth orbit (LEO) aerospace applications. However, PI substrates with low dielectric constant (low-Dk), low dielectric dissipation factor (low-Df) and high AO resistance have rarely been reported due to the difficulties in achieving both high AO survivability and good dielectric parameters simultaneously. In the present work, an intrinsically low-Dk and low-Df optically transparent PI film matrix, poly[4,4′-(hexafluoroisopropylidene)diphthalic anhydride-co-2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane] (6FPI) was combined with a nanocage trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP-POSS) additive in order to afford novel organic–inorganic nanocomposite films with enhanced AO-resistant properties and reduced dielectric parameters. The derived 6FPI/POSS films exhibited the Dk and Df values as low as 2.52 and 0.006 at the frequency of 1 MHz, respectively. Meanwhile, the composite films showed good AO resistance with the erosion yield as low as 4.0 × 10−25 cm3/atom at the exposure flux of 4.02 × 1020 atom/cm2, which decreased by nearly one order of magnitude compared with the value of 3.0 × 10−24 cm3/atom of the standard PI-ref Kapton® film.

Tribological properties and bearing application of Mo-based films in space environment

MoS2 film plays an important role in the field of space lubrication due to its excellent tribological properties, but the complex and changeable space environment has increasingly higher requirements for the lubricating layer. In order to improve the spatial tribological properties of the MoS2 film, the Mo-X (X = Pb, PTFE, C) binary composite films were prepared by radio frequency magnetron sputtering technology. Then, Mo/MoS2–Pb–PbS, Mo/MoS2-PTFE and Mo/MoS2–C films were obtained through the treatment of binary films by “low-temperature ion sulfurizing” technology. The structure, morphology and composition properties of the three films were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).The tribological properties of the three films were tested through ultraviolet (UV), atomic oxygen (AO) and high-vacuum simulated space environment, and the results showed that the Mo/MoS2–Pb–PbS film has better comprehensive spatial tribological properties. The Mo/MoS2–Pb–PbS film was applied to practical bearings, which were simulated for life test after exposure to space environment. The wear life of the new bearing is an order of magnitude higher than that of the active bearing. Therefore, Mo/MoS2–Pb–PbS film has broad application prospects in the field of space solid lubrication.

Atomic Oxygen-Resistant Polyimide Composite Films Containing Nanocaged Polyhedral Oligomeric Silsesquioxane Components in Matrix and Fillers

For the development of spacecraft with long-servicing life in low earth orbit (LEO), high-temperature resistant polymer films with long-term atomic oxygen (AO) resistant features are highly desired. The relatively poor AO resistance of standard polyimide (PI) films greatly limited their applications in LEO spacecraft. In this work, we successfully prepared a series of novel AO resistant PI composite films containing nanocaged polyhedral oligomeric silsesquioxane (POSS) components in both the PI matrix and the fillers. The POSS-containing PI matrix film was prepared from a POSS-substituted aromatic diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS) and a common aromatic diamine, 4,4′-oxydianline (ODA) and the aromatic dianhydride, pyromellitic dianhydride (PMDA) by a two-step thermal imidization procedure. The POSS-containing filler, trisilanolphenyl POSS (TSP-POSS) was added with the fixed proportion of 20 wt% in the final films. Incorporation of TSP-POSS additive apparently improved the thermal stability, but decreased the high-temperature dimensional stable nature of the PI composite films. The 5% weight loss temperature (T5%) of POSS-PI-20 with 20 wt% of DABA-POSS is 564 °C, and its coefficient of linear thermal expansion (CTE) is 81.0 × 10−6/K. The former is 16 °C lower and the latter was 20.0 × 10−6/K higher than those of the POSS-PI-10 film (T5% = 580 °C, CTE = 61.0 × 10−6/K), respectively. POSS components endowed the PI composite films excellent AO resistance and self-healing characteristics in AO environments. POSS-PI-30 exhibits the lowest AO erosion yield (Es) of 1.64 × 10−26 cm3/atom under AO exposure with a flux of 2.51 × 1021 atoms/cm2, which is more than two orders of magnitude lower than the referenced PI (PMDA-ODA) film. Inert silica or silicate passivation layers were detected on the surface of the PI composite films exposed to AO.

Facile method for fabricating atomic oxygen resistant polyimide films with excellent optical homogeneity containing hyperbranched polysiloxane

Mechanically robust optical homogeneous polyimide (PI) films with desirable atomic oxygen (AO) erosion duration were fabricated by initially synthesizing amine-functionalized hyperbranched polysiloxane (NH2-HBPSi), then reinforcing the pristine polyimide skeleton with it via copolycondensation reactions. NH2-HBPSi macromolecule imparts desirable AO survivability to the resulting hybrids. The mass loss per unit area of hybrid films had a downward trend with rising NH2-HBPSi content and AO dose before the complete silica protective layer was formed. It has been proven by the experiments in an underground simulated AO environment. It decreased to 1% of that of pristine polyimide when NH2-HBPSi accounted for 30% of the solid content after 24 h AO attack. The stable thickness uniformity that can meet the Rayleigh criterion was achieved in a 30 wt% HBPSi PI film, mainly due to the selection of the best process parameters. Meanwhile, 30 wt% HBPSi PI demonstrates satisfactory mechanical properties, with a tensile strength of 228.9 MPa and elongation at break of 7.3%. The characterization of scanning electron microscopy confirmed that pristine polyimide was substantially eroded after AO exposure while the surface morphology of 30 wt% HBPSi polyimide showed no evident change. The low AO erosion yield and prominent film thickness uniformity may find extensive usage in ultra-lightweight space diffractive optical elements (DOE) working in low earth orbit (LEO).

Quantifying the effects of hyperthermal atomic oxygen and thermal fatigue environments on carbon nanotube sheets for space-based applications

The effects of atomic oxygen and thermal fatigue on two different types of carbon nanotube sheets were studied. One set was treated with nitric acid, while the other set was left untreated. Monotonic tensile tests were performed before and after exposure to determine the effects of either exposure type on the sheets’ mechanical properties. Electrical conductivity and electromagnetic interference measurements were recorded to determine the effects of AO-exposure and thermal cycling on the sheets’ electrical properties. Neither exposure type affected the sheets’ specific strengths. Both exposure types increased the sheets’ specific stiffnesses and decreased the sheets’ strains at failure. The electrical conductivity of both sheets decreased due to the different exposure types, while the EMI shielding effectiveness was unaffected. Scanning electron microscopy was used to observe any changes in the sheets’ surface morphologies, while energy-dispersive X-ray spectroscopy was used to determine the effects of AO on the sheets’ chemical makeup.

Atomic Oxygen Adaptability of Flexible Kapton/Al2O3 Composite Thin Films Prepared by Ion Exchange Method

Polyimide film (Kapton) is an important polymer material used for the construction of spacecrafts. The performance of Kapton can be degraded for atomic oxygen erosion in space. Commonly used atomic oxygen protective layers have issues such as poor toughness and poor adhesion with the film. In this paper, Kapton/Al2O3 nanocomposite films were prepared via an ion exchange method, and the optical properties, mechanical properties, and mechanisms for the change in the mass and microstructure, before and after atomic oxygen exposure, were analyzed. The results show that the deposition of the Kapton/Al2O3 surface nanocomposite film prepared via the ion exchange method has no obvious effects on the internal structure and optical transmittance of the Kapton film matrix. The tensile strength and elongation of the prepared film were much higher than those of the pure Kapton film, demonstrating its good flexibility. Scanning electron microscope (SEM) analysis showed that the etching pits had a carpet-like morphology on the composite film surface and were relatively small after atomic oxygen erosion. In contrast with the C–C bond rupture in the oxydianiline (ODA) benzene in Kapton films, the Kapton/Al2O3 nanocomposite film mainly destroyed the C=C bond in the pyromellitic dianhydride (PMDA) benzene ring. On exposure to an atomic oxygen environment for a short period, the Kapton/Al2O3 nanocomposite film exhibited improved atomic oxygen erosion resistance because the Al2O3 layer inhibited atomic oxygen diffusion. With increasing atomic oxygen exposure time, the atomic oxygen diffused into the Kapton matrix via the pores of the Al2O3 layer, causing damage to the substrate. This resulted in a detachment of the surface Al2O3 layer and exposure of the Kapton matrix, and thereby the atomic oxygen resistance was decreased. The applicability of the ion exchange mechanism of trivalent Al element on the surface modification of the polyimide is explored in this study. The behavior of the Kapton/Al2O3 composite film under the atomic oxygen environment of space is investigated, which provides the basis for studying the effects of atomic oxygen on the flexible protective Kapton film.

Self-Healing Anti-Atomic-Oxygen Phosphorus-Containing Polyimide Film via Molecular Level Incorporation of Nanocage Trisilanolphenyl POSS: Preparation and Characterization.

Protection of polymeric materials from the atomic oxygen erosion in low-earth orbit spacecrafts has become one of the most important research topics in aerospace science. In the current research, a series of novel organic/inorganic nanocomposite films with excellent atomic oxygen (AO) resistance are prepared from the phosphorous-containing polyimide (FPI) matrix and trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP–POSS) additive. The PI matrix derived from 2,2’-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,5-bis[(4-amino- phenoxy)phenyl]diphenylphosphine oxide (BADPO) itself possesses the self-healing feature in AO environment. Incorporation of TSP–POSS further enhances the AO resistance of the FPI/TSP composite films via a Si–P synergic effect. Meanwhile, the thermal stability of the pristine film is maintained. The FPI-25 composite film with a 25 wt % loading of TSP–POSS in the FPI matrix exhibits an AO erosion yield of 3.1 × 10−26 cm3/atom after an AO attack of 4.0 × 1020 atoms/cm2, which is only 5.8% and 1.0% that of pristine FPI-0 film (6FDA-BADPO) and PI-ref (PMDA-ODA) film derived from 1,2,4,5-pyromellitic anhydride (PMDA) and 4,4’-oxydianline (ODA), respectively. Inert phosphorous and silicon-containing passivation layers are observed at the surface of films during AO exposure.

Responses of TMDs-metals composite films to atomic oxygen exposure

To clarify the ability of reactive metals alloyed transition metal disulfides (TMDs) films resistant to low-earth-orbit (LEO) space exposure, the MoS2-16 at. % Ag film was sputtered and exposed in long-term atomic oxygen (AO) environment. Results revealed the MoS2-Ag composite film could be severely oxidized by the AO irradiation. The 2H-MoSxOy matrix was severely oxidized to MoO3 and MoO2, and the alloyed Ag was partially oxidized to Ag2O. The volume expansion from the oxidation of Ag to Ag2O was responsible for the cracking and thereby severe oxidation of brittle 2H-MoSxOy platelets in the composite film. Furthermore, the re-growth of Ag induced by the AO irradiation was also observed in the initial stage of AO irradiation. Due to the oxidization, the film morphology was changed from the characteristic dentrite-like surface for the non-irradiated film to the terrace-like one for the irradiated film and eventually to the chrysanthemum-like one as increasing the AO fluence. Wear tests revealed that the wear resistance of MoS2 film in vacuum environment could be significantly improved. However, the wear resistance of MoS2-Ag composite film was obviously deteriorated because of the severe oxidation from the AO irradiation. The wear life of MoS2-Ag composite film was sharply reduced from ∼7.6 × 105 cycles before the AO irradiation to ∼4.9 × 104 cycles after the AO irradiation of 5.6 × 1026 atoms∙m−2. These results indicated that for the selection of solid lubricants in LEO space environment, the reactive metals alloyed TMDs films should be excluded as possible as to eliminate potential risks.

MoS2-Sb2O3 film exhibiting better oxidation-resistance in atomic oxygen environment

The microstructure and wear resistance of sputtered MoS2 films can be improved by adding some amount of metals. However, the oxidation-resistance of MoS2-metals films would be worried because some metals are sensitive to atomic oxygen (AO). In this paper, the inert Sb2O3 was introduced into the MoS2 film, and its effect on the structure and anti-oxidation ability of the MoS2 film was clarified. XRD and SEM results revealed that due to the addition of Sb2O3, the growth of MoS2 micro-platelets was almost suppressed, and so the composite film was amorphous and very compact. XPS analysis indicated that for the composite film, the influence by the AO irradiation was restricted into the film surface layer. Namely, the composite film exhibited a better anti-oxidation ability in the AO environment.

Study on performances of colorless and transparent shape memory polyimide film in space thermal cycling, atomic oxygen and ultraviolet irradiation environments

Shape memory polymers with high glass transition temperature (HSMPs) and HSMP-based deployable structures and devices, which can bear harsh operation conditions for durable applications, have attracted more and more interest in recent years. In this article, colorless and transparent shape memory polyimide (SMCTPI) films were subjected to simulated vacuum thermal cycling, atomic oxygen (AO) and ultraviolet (UV) irradiation environments up to 600 h, 556 h and 600 h for accelerated irradiation. The glass transition temperature (Tg) determined by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) had no obvious changes after being irradiated by varying amounts of thermal cycling, AO and UV irradiation dose. After being irradiated by 50 thermal cycles, 10 × 1021 atoms cm–2 AO irradiation and 3000 ESH UV irradiation, shape recovery behaviors of SMCTPI films also had no obvious damage even if they experienced 30 shape memory cycles, while the surface morphologies and optical properties were seriously destroyed by AO irradiation, as compared with thermal cycling and UV irradiation. The tensile strength could separately maintain 122 MPa, 120 MPa and 70 MPa after 50 thermal cycles, 10 × 1021 atoms cm–2 AO irradiation and 3000 ESH UV irradiation, which shows great potential for use in aerospace structures and devices.

Substantially enhanced durability of polyhedral oligomeric silsequioxane-polyimide nanocomposites against atomic oxygen erosion

Several groups of polyimide (PI)-based nanomaterials reinforced with polyhedral oligomeric silsequioxane (POSS) nanoparticles were subjected to atomic oxygen (AO) exposure to investigate the effects of POSS and glassification plasma pre-treatment. Various characterizations revealed the clear effects of AO degradation, such as decreased transmissions of all tested films. POSS significantly enhanced the stability of PI in terms of mass loss under an AO environment. One polyimide film sample containing 10wt% POSS also exhibited excellent stability in mechanical properties measured by dynamic mechanical analyzer (DMA). Surface topography and roughness of all films were qualitatively and quantitatively analyzed using the atomic force microscope (AFM). After AO irradiation the POSS-filled films showed a much smoother surface than that of neat PI film. The results of mass loss, mechanical property and AFM topography collectively indicate the exceptional self-healing capability of the POSS nanoparticles upon AO erosion that enables it to protect polyimide due to the formation of a thin glass layer. A further molecular dynamics simulation of the neat PI and PI-POSS system revealed reduced mass loss, damage propagation depth, and erosion yield of the nanocomposites with increasing POSS concentration, which are consistent with the experimental findings.

CVD nano-coating of carbon composites for space materials atomic oxygen shielding

Abstract: The present work analyzes the possibility to employ carbon nanostructures as a basic material to prevent the erosion effects of atomic oxygen suffered by the carbon fiber reinforced polymeric material used in low earth orbit space environment. The application of thin protecting coatings to base materials is a widely used method for preventing the atomic oxygen induced erosion, and thus degradation. The generic purpose is to integrate carbon nanostructures onto carbon composites surface in order to develop the basic substrate of advanced nanocomposite for atomic oxygen protection. The final goal is the characterization of carbon nanostructures-reinforced carbon composites by means of on-ground atomic oxygen simulation facility, with the future objective to assess and optimize the process of carbon-multiscale advanced composites production. With such an aim, a wide investigation on the methane chemical vapor deposition (CVD) over catalyzed carbon fiber-based substrates has been carried out. The as grown nanostructures have been analyzed in terms of morphology, as well as regarding the main features of the resulting growth (yield, purity, homogeneity, coating uniformity, etc.) and the influence of the deposition route operating parameters (catalyst typology, gas flowing rate, growth time/temperature, etc.). A high degree of reproducibility in terms of the relationship between the carbon deposit type/yield and the main process variables (catalyst and protocol) has been thus obtained. Finally, atomic oxygen ground tests have been conducted in order to evaluate the coating process effectiveness. The on-ground test in atomic oxygen environment, with respect to the performances of the reference carbon composites (in terms of total mass loss and atomic oxygen rate of erosion), showed a worsening for the disordered carbon deposit, while an intriguing improvement was achieved by the high-yield carbon nano-filaments deposition.

AO-resistant properties of polyimide fibers containing phosphorous groups in main chains

A series of polyimide fibers containing phosphorus element derived from (3-aminophenyl) methyl phosphine oxide (DAMPO) diamine was exposed to an artificial atomic oxygen environment which simulated the space environment in low earth orbit (LEO). The mass loss, surface morphology, chemical composition, and mechanical properties of the fibers before and after atomic oxygen (AO) exposure were compared in detail with a blank sample. Results showed that the phosphor-containing fibers demonstrated lower mass change and less tensile strength reduction. SEM results showed that the fibers with phosphorous element had relatively dense surface after AO exposure. Meanwhile, XPS results indicated that a passivated phosphate layer, which could protect the following under-layer from attacking by AO, was formed on the surface of the fibers. These results indicated that the incorporation of diamine (DAMPO) into the main chains could protect the fibers for avoiding further erosion from AO exposure. Hence, the phosphor-containing PI fibers exhibits potential application in space fields.