Aerospace Exploration Research Articles

Interface Engineering via Manipulating Solvation Chemistry for Liquid Lithium-Ion Batteries Operated≥100 °C.

High-performance and temperature-resistant lithium-ion batteries (LIBs), which are able to operate at elevated temperatures (i.e., >60 °C) are highly demanded in various fields, especially in military or aerospace exploration. However, their applications were largely impeded by the poor electrochemical performance and unsatisfying safety issues, which were induced by the severe side reactions between electrolytes and electrodes at high temperatures. Herein, with the synergetic effects of solvation chemistry and functional additive in the elaborately designed weakly solvating electrolyte, a unique robust organic/inorganic hetero-interphase, composed of gradient F, B-rich inorganic components and homogeneously distributed Si-rich organic components, was successfully constructed on both cathodes and anodes, which would effectively inhibit the constant decomposition of electrolytes and dissolution of transition metal ions, thus highly enhancing the high-temperature electrochemical performance. As a result, both cathodes and anodes, without compromising their low-temperature performance, can operate at temperatures ≥100 °C, with excellent capacity retentions of 96.1 % after 500 cycles and 93.5 % after ≥200 cycles, respectively, at 80 °C. Ah-level LiCoO2||graphite full cells with a cut-off voltage of 4.3 V also exhibited superior temperature-resistance with a capacity retention of 89.9 % at temperature as high as 120 °C. Moreover, the fully charged pouch cells exhibited highly enhanced safety, demonstrating their potentials in practical applications at ultrahigh temperatures.

Interface Engineering via Manipulating Solvation Chemistry for Liquid Lithium‐Ion Batteries Operated≥100 °C

AbstractHigh‐performance and temperature‐resistant lithium‐ion batteries (LIBs), which are able to operate at elevated temperatures (i.e., >60 °C) are highly demanded in various fields, especially in military or aerospace exploration. However, their applications were largely impeded by the poor electrochemical performance and unsatisfying safety issues, which were induced by the severe side reactions between electrolytes and electrodes at high temperatures. Herein, with the synergetic effects of solvation chemistry and functional additive in the elaborately designed weakly solvating electrolyte, a unique robust organic/inorganic hetero‐interphase, composed of gradient F, B‐rich inorganic components and homogeneously distributed Si‐rich organic components, was successfully constructed on both cathodes and anodes, which would effectively inhibit the constant decomposition of electrolytes and dissolution of transition metal ions, thus highly enhancing the high‐temperature electrochemical performance. As a result, both cathodes and anodes, without compromising their low‐temperature performance, can operate at temperatures ≥100 °C, with excellent capacity retentions of 96.1 % after 500 cycles and 93.5 % after ≥200 cycles, respectively, at 80 °C. Ah‐level LiCoO2||graphite full cells with a cut‐off voltage of 4.3 V also exhibited superior temperature‐resistance with a capacity retention of 89.9 % at temperature as high as 120 °C. Moreover, the fully charged pouch cells exhibited highly enhanced safety, demonstrating their potentials in practical applications at ultrahigh temperatures.

Pseudo-Drag-Free System Simulation for Bepicolombo Radio Science Using Accelerometer Data

The Mercury Orbiter Radio Science Experiment onboard the European Space Agency/Japan Aerospace Exploration Agency (JAXA) BepiColombo mission aims at determining the gravity field and the rotational state of the planet to provide insight into its internal structure and at performing tests of general relativity. The experiment will rely on accurate radiometric data provided by the onboard Ka-band transponder and on measurements of the nonconservative perturbations acting on the spacecraft, provided by the Italian Spring Accelerometer. This paper presents a software implementation of a pseudo-drag-free system which includes the accelerometer measurements in the orbit determination process. Numerical simulations focus on the identification of a suitable calibration strategy to fulfill the experiment goals pertaining to geodesy and geophysics. The achievement of the expected scientific results will depend meaningfully on the quality of the accelerometer data. Perturbative analysis aided in the identification of a calibration strategy for the accelerometer data processing that allows obtaining an unbiased solution and compensating for accelerometer errors.

METAL ADDITIVE MANUFACTURING IN SPACE AND AEROSPACE EXPLORATION: CURRENT PROCESSES, MATERIAL SELECTION AND CHALLENGES

Space and aerospace exploration have the highest regulations regarding design and manufacturing processing. As a result, an immense multi-tier manufacturing system has been developed because of the tooling and machinery associated with the production of high-grade spacecraft and aircraft. Furthermore, the nature of the supply chain and hefty capital investments further complicate spacecraft and aircraft manufacturing. Metal additive manufacturing (AM) offers the best solution to produce complex parts from digital information without the need for large amounts of tooling and machinery. MAM represents a promising aspect of innovations to revolutionize the way manufacturing is designed and constructed for many applications. Moreover, various research activities are being carried out in the aerospace industry for MAM process, which produces parts that would be impossible to create using conventional manufacturing (CM) methods. MAM has gained popularity in recent years from its initial stages of development in the research phase to providing a wide range of functional applications in the aerospace industry to manufacture and repair a wide range of components used in spacecraft and aircraft. The significant growth in MAM process can be attributed to its commercial and performance advantages within the aerospace industry. In this paper, a detailed assessment of existing MEM processes is presented, emphasizing the ability to manufacture and repair metal parts for the aerospace industry, providing information about the materials currently in use, as well as identifying possible future applications and challenges. There is no doubt that the information provided in this study will support exploring MAM’s new opportunities for future needs in space and aerospace exploration.

Adaptive iterative learning control and inverse compensation of macro fiber composite system with hysteresis

Macro fiber composite (MFC) actuators, which exhibit excellent flexibility and strong deformability, are widely used in aerospace exploration, flexible robotics, and other applications. However, the rate-dependent hysteresis nonlinearity of the flexible beam driven by MFCs significantly affects positioning accuracy. This study utilizes a new Hammerstein model to describe the hysteresis of an MFC system and proposes a control strategy that combines adaptive iterative learning control and inverse compensation. The adaptive iterative learning control allows the learning gain parameters to be adjusted based on the tracking error. A high gain ensures the convergence speed of iterative learning, whereas a small learning gain provides high robustness and convergence accuracy. Trajectory tracking experiments are conducted to verify the effectiveness of the proposed control strategy. Compared with the case of direct inverse compensation, after the sixth iteration, the tracking maximum absolute error, relative error, and corresponding root mean square error of the proposed control strategy reduce by 73% on average. Moreover, compared with the case of P-type iterative learning control combined with inverse compensation, the metrics above reduce by 12% on average. The proposed control strategy offers higher tracking accuracy and greater practicality in the trajectory tracking of MFC systems.

Ferroconcrete-inspired construction of wearable composites with a natural leather matrix for excellent neutron-shielding performance

In various sectors, including medical radiotherapy, aerospace exploration, and nuclear energy, the necessity for advanced neutron-shielding materials has escalated. However, these materials often exhibit poor mechanical performance and limited adaptability. To address these shortcomings, this study introduces a novel approach inspired by ferroconcrete construction to develop wearable neutron-shielding materials. This method utilizes the collagen fiber-supported framework present in natural leather, serving as a flexible skeleton, and employs functionalized B4C nanoparticles and paraffin as fillers. The interconnected voids and the unique hierarchical structure of the collagen fibers work synergistically to enable uniform dispersion of B4C nanoparticles, thus enriching the resultant composites with superior neutron-shielding performance. The composite material prepared through this method exhibits a remarkable neutron-shielding effectiveness of 96.93 % and a high linear attenuation coefficient of 17.46 cm−1, outperforming other shielding materials. Additionally, the three-dimensional (3D) woven network of the collagen fiber-supported framework offers impressive mechanical properties, including a tensile strength of 28.59 MPa. This innovative design strategy for creating new wearable neutron-shielding materials paves the way for manufacturing advanced neutron-protective clothing and propels a new structural design with elevated shielding and mechanical performance.

Rechargeable Battery for Ultra Low Temperature Environments

Rechargeable energy storage systems that can efficiently operate at ultra-low temperatures down to -50°C or lower are needed to support Arctic zone development and aerospace exploration. Existing batteries today such as Li-ion and Pb-acid batteries all lose functions at colder temperatures. We have discovered a battery chemistry for which the amount of energy stored actually increases as temperature decreases, and storage cost commensurately decreases. Furthermore, this novel battery is composed of low-cost, widely available materials, and has a simple design that is self-assembling. In our study, we develop the zinc battery system composed of a pair of immiscible liquid electrodes that density-based self-assembly into a layered configuration without a membrane separator. This allows the zinc negative electrode to use low-cost iron or steel packaging that simultaneously serves as the current collector, while a reversible chlorine electrode serves as the positive electrode. The use of liquid electrolytes allows inherent stress relaxation suggesting high cycle life. We investigate anode and cathode solution chemistry, chlorine electrode redox kinetics including catalyst development, and integration of components into prototype batteries. Our progress shows promising battery cycling performance below 0°C, and indicates the technoeconomic feasible through technoeconomic analysis.This abstract submission is for session A1-Triple I.Reference: Li, Zheng, et al. "Air-breathing aqueous sulfur flow battery for ultralow-cost long-duration electrical storage." Joule1.2 (2017): 306-327. Landolt, D.; Ibl, N. (1972). "Anodic chlorate formation on platinized titanium". Journal of Applied Electrochemistry. Chapman and Hall Ltd. 2(3): 201–210. DOI:10.1007/BF02354977. S2CID 95515683.Hale, Arthur (1918). The Applications of Electrolysis in Chemical Industry. Longmans, Green, and Co. p. 13. Retrieved 2019-09-15.

A large depth-of-field virtual measurement network for non-cooperative 6DOF pose estimation in occlusion scenes

Six degrees of freedom (6DOF) measurement capable of determining the rigid transformation is a vital task in aerospace exploration and autonomous navigation. In this paper, a large depth-of-field virtual measurement network is proposed based on a moving rotating-prism-embedded camera to achieve 6DOF pose estimation for non-cooperative partially occluded targets. It includes stereo recovery using dense beam localization and accurate absolute orientation based on dual quaternions and adaptive scale factors. The former allows the three-dimensional (3D) extraction by multiview large-parallax imaging, while the latter enables the decoupling of translation and orientation without initial value estimation to avoid error accumulation. Compared to the mainstream methods, our method provides high-quality pose metrology, especially for depth extraction. The experiments show that the architecture allows the 3D reconstruction and non-cooperative 6DOF estimation with a large depth of field and object occlusion, solving the problem of difficult compromise between long-baseline imaging and compact configuration.

Self-calibrated free-running dual-comb ranging using subsampled repetition frequency information

Dual-comb ranging (DCR) is an emerging absolute distance measurement method with rapid speed, high precision, and wide ambiguity range. DCR has important applications in remote sensing, large-scale manufacturing, and aerospace exploration. However, the typical DCR system requires cumbersome phase-locking electronics for frequency stabilization and distance calibration, which hinders the practical application of DCR. In this paper, we demonstrate a free-running DCR scheme based on two free-running mode-locked fiber lasers. Two fiber lasers are environment-shared to improve the anti-aliasing capability. We then introduce a self-calibration technique that can directly extract the subsampled repetition frequency information from the interferograms (IGMs). By using this technique, real-time calibration of measured distance can be achieved without extra repetition frequency detection module and frequency counter. The system realizes a 5.3 µm precision for ∼1 m stand-off distance at ∼1 kHz acquisition speed. With averaging, the measurement precision drops to ∼101 nm at the averaging time of 3 s. The ambiguity range of our DCR system is ∼2.6 m due to the relatively small repetition frequency. For dynamic distance measurement, it shows good consistency with a commercial heterodyne interferometer. Our method provides a cost-effective scheme for high-performance absolute distance measurement, and it is promising for promoting DCR system out of the laboratory and realizing field-deployed applications.

Rigid/flexible molecular structure‐induced polyimide aerogels with ultralow permittivity and thermal insulation properties

AbstractA series of high‐performance linear and cross‐linked polyimide (PI) aerogels with different molecular structures have been successfully synthesised using the freeze‐drying process. In this study, the comprehensive regulation of microstructure, thermodynamic, thermal insulation and dielectric properties of PI aerogels are achieved by controlling the rigid/flexible structure and composition of polymerised monomers. The increase in rigidity of PI molecular structure could promote the formation of denser pores, which is beneficial to improve the thermodynamic and thermal insulation properties of aerogels. Notably, the cross‐linked PI aerogel prepared by introducing cross‐linking agent (tris(4‐aminophenyl) amine, [TPA]) into linear PI exhibits high thermal stability (Td5% > 560°C), excellent ultralow permittivity (εr = 1.31, f = 106 Hz) and good thermal insulation property (k = 0.056 W/m · K). This innovative strategy promotes the wider application of the cross‐linked polyimide aerogel in the field of integrated circuits and aerospace exploration.

Morphology constraint of β-HMX in polymeric carbon nitrides towards hybrid energetic materials

The exploration of hybrid energetic materials is of great importance because of their enhanced performances and promising applications in aerospace exploration, military and civil technologies. Herein, a new type hybrid energetic material is prepared by the integration of energetic molecule HMX and polymeric carbon nitrides (PCNs). Two PCNs-HMX were prepared from melem and melem hydrazine by in-situ self-assembly on HMX with glyoxal, the complexes were named as MGP-HMX and MHGP-HMX, respectively. The planar structure and conjugated π-system of 2D-PCNs benefit the reduced sensitivities and help to control the polymorphism of HMX. The hybrid complexes MGP-HMX and MHGP-HMX demonstrate remarkably high thermal stabilities. An interesting morphology constraint effect of β-HMX is observed only for the hydrazone-linked MHGP, but not for the imine-linked MGP. The constraint effect blocks the solid–solid transition of HMX from high energetic β-phase to low energetic δ-phase. The key to constrain the solid–solid morphology transition in MHGP-HMX is furtherly investigated by visualization of the interaction in composite materials. The massive hydrogen bonds between NO2 groups of HMX and hydrazone moieties of MHGP and the squeezing of HMX in 2D layers account for the morphology constrain. The morphology constraint via PCNs provides a new strategy for the construction of new hybrid energetic materials with high thermostability and low sensitivity.

Mechanical Properties Evolution and Damage Mechanism of Kevlar Fiber under Ozone Exposure in Near-Space Simulation

The stratospheric airship, a long-term floating vehicle in near-space, has become a new hotspot in aerospace exploration. The airship’s envelope material is vulnerable to ozone exposure in near-space and degrades. This paper used typical Kevlar fiber as the research material for an ozone exposure experiment in a near-space simulated environment. The results showed that the elongation of the Kevlar fiber decreased and the elastic modulus increased after ozone exposure. The tensile strength of fiber decreased gradually with an increase in ozone concentration and exposure time. When ozone concentration increased from 0 pphm to 1000 pphm, the tensile strength of fiber decreased from 2397 MPa to 2059 MPa. With increasing ozone exposure time from 0 h to 1000 h under ozone concentration 1000 pphm, the tensile strength of fiber decreased from 2332 MPa to 1954 MPa. The hydrogen bonds and partial amide groups in the fiber structure were damaged, and the surface chemical functional groups of the Kevlar fiber were reassembled under ozone exposure. Low molecular weight oxidation products, including -COO- structures, formed on the surface of the Kevlar fiber. This work explores the ground simulation method in a near-space environment and enriches the service data of airship envelope materials.

Additive Manufacturing of Resilient SiC Nanowire Aerogels.

Resilient ceramic aerogels are emerging as a fascinating material that features light weight, low thermal conductivity, and recoverable compressibility, promising widespread prospects in the fields of heat insulation, catalysis, filtration, and aerospace exploration. However, the construction of the resilient ceramic aerogels with rational designed multiscale architectures aiming for tunable physical and mechanical performances remains a major challenge. Here, 3D constructed resilient SiC nanowire aerogels possessing programmed geometries and engineered mechanical properties are created via additive manufacturing. The Young's modulus of the fabricated SiC nanowire aerogel lattices are tuned systematically from 0.012 MPa to 5.800 MPa spanning over 2 orders of magnitude. More importantly, the customized lightweight and resilient SiC nanowire aerogels show a low thermal conductivity (0.046 W m-1 K-1). The present work provides another approach to the design and rapid fabrication of resilient ceramic aerogels toward flexible thermal management devices, lightweight engineered structures, and other potential applications.

Measuring the electrostatic charges of a single particle in contact electrification

Taking regolith samples by unmanned equipment is a popular method to understand the outerspace in aerospace exploration. The electrostatic sampler can drive the charged particles to move or be transported by strong electric intensity, and its driving ability is extraordinarily powerful in the low gravity environment. The amount of charge acquired by a particle is vital to understand its dynamic behaviour in an electric field. In this study, the model of contact charging for a single particle is discussed to present its detailed behaviour during its charging process. Further, a suspension balancing method (SBM) is proposed for measuring the charges of a single particle. The experimental result fits well with the amended single-particle charging model. The experimental and simulation results prove that the charging source of a particle dynamically approaching the electrode can be attributed not only to the contact electrification but also to the air discharge.

Equivalent virtual cameras to estimate a six-degree-of-freedom pose in restricted-space scenarios

Multi-dimensional information extraction for objects in restricted-space scenarios plays a pivotal role in flouring fields such as aerospace exploration, smart manufacturing, and biomedical observation. In this paper, we proposed a robust and accurate six-degree-of-freedom pose estimation method based on equivalent virtual cameras, which enables six degrees of freedom (6DoF) reconstruction using rotation averaging and computational imaging. It consists of rotation estimation to extract orientation and translation estimation for position recovery. The former with a feature that a rotating-prism-integrated static camera stares at control points from constrainable view arrays, and the latter with a feature that multiple virtual cameras split from the camera gaze at control points in a one-to-one correspondence. Compared with leading monocular approaches, our architecture achieves accurate measurement despite few control points and large noise. The experimental results show that our architecture achieves 6DoF measurement with means errors better than 0.4 mm and 0.4° competitive to conventional multi-camera vision.

Thick-panel Origami Cube

This paper presents a new method for constructing a novel thick-panel origami cube. By replacing the equivalent 4R-spherical linkage in a four-crease zero-thickness origami vertex with a plane-symmetric Bricard linkage, the thick-panel form of a general plane-symmetric four-crease origami vertex is identified and constructed. The proposed thick-panel vertex preserves the kinematics of the original four-crease origami vertex. Then, by utilizing the proposed thick-panel vertex, a thick-panel cube is constructed based on the zero-thickness origami cube that was proposed in our previous work. Through mechanism decomposition, geometric constraints and kinematic properties of the corresponding integrated mechanism are investigated and formulated, which reveals the kinematic equivalence between the thick-panel and zero-thickness forms of the origami cube. In addition, a prototype of the proposed thick-panel origami cube is fabricated, verifying its kinematic properties. The proposed technique can be extended to the design and construction of thick-panel polyhedrons with potential applications in the fields such as aerospace exploration, robotics and architecture.

Smart Autonomous Moving Platforms

In recent years, several advances in artificial intelligence such as deep learning, computer vision, automatic driving, cognitive computing, and robotics, have laid the technological foundation for the large-scale application of Smart-AMPs in complex environments. Potential solutions have appeared for smart transportation, aerospace exploration, smart logistics and smart cities. This article summarizes all kinds of autonomous moving platforms, proposes a definition of Smart- AMPs, and investigates taxonomy, technologies, applications, open issues and key challenges for Smart-AMPs. This article is suitable as a pedagogical overview of Smart-AMPs.

Visual clarity methylammonium lead trichloride perovskite single crystals for X and gamma rays protection

Ionization radiation photons such as X-ray and gamma ray have been widely applied in the nuclear power industry, medical imaging, scientific research, and aerospace exploration. Developing a protective material with excellent shielding properties and clear visibility is an urgent demand in order to protect people who are working in a radiation environment. Hence, we present a highly efficient radiation shielding material based on lead halide organic-inorganic perovskite single crystals with visual clarity, high efficiency and attenuation coefficient, and thin half-value layer. Our results indicate that the shielding performances (mass attenuation coefficients, effective atomic numbers and half value layer) of the perovskite crystals are at least one order higher than the current commercial products, such as Bone-equivalent plastic, Polyethylene terephthalate, and colorless glass. In addition, physical properties (density), and optical properties (transmission, refractive index), can be slightly tuned by the dopant Br concentration in crystals. The present results demonstrate that the organic-inorganic perovksite single crystals are optimized for high attenuation radiation shielding materials with visual clarity.

Simulating precipitation radar observations from a geostationary satellite

Abstract. Spaceborne precipitation radars, such as the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) Core Observatory, have been important platforms to provide a direct measurement of three-dimensional precipitation structure globally. Building upon the success of TRMM and GPM Core Observatory, the Japan Aerospace Exploration Agency (JAXA) is currently surveying the feasibility of a potential satellite mission equipped with a precipitation radar on a geostationary orbit. The quasi-continuous observation realized by the geostationary satellite radar would offer a new insight into meteorology and would advance numerical weather prediction (NWP) through their effective use by data assimilation. Although the radar would be beneficial, the radar on the geostationary orbit measures precipitation obliquely at off-nadir points. In addition, the observing resolution will be several times larger than those on board TRMM and GPM Core Observatory due to the limited antenna size that we could deliver. The tilted sampling volume and the coarse resolution would result in more contamination from surface clutter. To investigate the impact of these limitations and to explore the potential usefulness of the geostationary satellite radar, this study simulates the observation data for a typhoon case using an NWP model and a radar simulator. The results demonstrate that it would be possible to obtain three-dimensional precipitation data. However, the quality of the observation depends on the beam width, the beam sampling span, and the position of precipitation systems. With a wide beam width and a coarse beam span, the radar cannot observe weak precipitation at low altitudes due to surface clutter. The limitation can be mitigated by oversampling (i.e., a wide beam width and a fine sampling span). With a narrow beam width and a fine beam sampling span, the surface clutter interference is confined to the surface level. When the precipitation system is located far from the nadir, the precipitation signal is obtained only for strong precipitation.

A 220 GHz Broadband Sub-Harmonic Mixer Based on Global Design Method

A terahertz mixer is one of terahertz key components and widely used on terahertz wireless communication, remote sensing, aerospace exploration, and biomedical system. The performance of the terahertz mixer has a great effect on the entire terahertz transceiver system performance. This paper proposes a 220 GHz broadband sub-harmonic mixer based on global design method (GDM), which is different from the traditional subdivision design method of which the mixer circuit is composed of functional unit circuits. Instead, the GDM adopts the overall performance of the mixer (conversion loss) as an optimization goal. The continuous structures of the circuit are described by ideal transmission line models and waveguide models, meanwhile, the S-parameters of the de-embedded model are used to describe the discontinuous structures. The measured single-sideband (SSB) conversion loss is basically consistent with the simulation results, which verifies the accuracy and reliability of the GDM. When local oscillator (LO) frequency is fixed at 110 GHz, the measured SSB conversion loss is less than 10 dB with the average value of 8.1 dB from 198 to 238 GHz. The minimum conversion loss of the mixer is 6.35 dB at 207 GHz. The measured double-sideband noise temperature of the mixer is less than 924 K at an intermediate frequency of 1.6 GHz. The GDM has the characteristics with a wide frequency band, small circuit size, simple structure, low LO power, and stable performance, and can also be applied to other terahertz components.