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The deep cryogenic temperatures encountered in aerospace present significant challenges for the performance of elastic materials in spacecraft and related apparatus. Reported elastic carbon or ceramic aerogels overcome the low-temperature brittleness in conventional elastic polymers. However, complicated fabrication process and high costs greatly limited their applications. In this work, super-elasticity at a deep cryogenic temperature of covalently crosslinked polyimide (PI) aerogels is achieved based on scalable and low-cost directional dimethyl sulfoxide crystals assisted freeze gelation and freeze-drying strategy. The covalently crosslinked chemical structure, cellular architecture, negative Poisson’s ratio (−0.2), low volume shrinkage (3.1%), and ultralow density (6.1 mg/cm 3 ) endow the PI aerogels with an elastic compressive strain up to 99% even in liquid helium (4 K), almost zero loss of resilience after dramatic thermal shocks (∆ T  = 569 K), and fatigue resistance over 5000 times compressive cycles. This work provides a new pathway for constructing polymer-based materials with super-elasticity at deep cryogenic temperature, demonstrating much promise for extensive applications in ongoing and near-future aerospace exploration. The deep cryogenic temperatures present significant challenges for the performance of elastic materials. Here, the authors present a low density covalently crosslinked polyimide (PI) aerogels with super-elastic properties at deep cryogenic temperatures.

In recent planetary exploration space missions, spacecraft are exposed to severe thermal environments that are sometimes more extreme than those experienced in earth orbits. The development of advanced thermal control materials and devices together with reliable and accurate measurements of their thermophysical properties are needed for the development of systems designed to meet the engineering challenges associated with these space missions. We provide a comprehensive review of the state-of-the-art advanced passive thermal control materials and devices that are available for space applications, specifically, variable emissivity thermal control materials and microelectromechanical systems (MEMS), radiofrequency (RF)-transparent and/or tunable solar absorptivity and total hemispherical emissivity thermal control materials, and a passive re-deployable radiator with advanced materials and insulation. Prior to our in-depth review of these thermal control materials, we briefly summarize the thermal environments surrounding spacecraft, the characteristics of thermophysical properties for spacecraft materials that differ from those of materials for ground use, and the significance of solar absorptivity and total hemispherical emissivity for passive thermal control in space. In all four topics of materials and devices, the following subjects are overviewed: the basic principle of passive thermal control techniques in space, the measurement of thermophysical properties of those novel materials, simulation and/or on-orbit verification thermal performance tests, degradation tests in space environments, and some aspects of the implementation of the above-described materials and devices in actual space missions.

XIV International Conference on Recent Advances in Structural Dynamics (RASD)The RASD conference series was initiated by the late Professor Maurice Petyt of the Institute of Sound and Vibration Research (ISVR), Southampton, in 1980 “to review the advances which have been made in the theory and practice of structural dynamics … leading to a valuable exchange of ideas and form the basis for new developments”. Following a successful and hugely enjoyable sojourn in Lyon, 2019, and a delay due to the Covid 19 pandemic, the fourteenth conference returned in July 2024 to its inaugural venue, with the same aim. Just over 100 talks were presented during three days, including the following inspirational keynote addresses:Mahmoud Hussein Metadamping and metaharvesting: Vibration engineering at the intrinsic material levelGuglielmo Aglietti Vibration testing of spacecraft structure - Virtual Testing & Multi DoF ShakersJason Zheng Jiang Generative design for dynamic performance transformationThe drinks and canape reception at Solent Sky aircraft museum was a highlight for attendees from all engineering backgrounds.List of Organising committee is available in this Pdf.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and less than 180 ng/cm(exp 2) of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Samples returned from C-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 spacecraft provide material free of terrestrial alteration for analysis. Previous work shows that Ryugu was aqueously altered below 100 °C under neutral to alkaline fluid conditions. Such low-temperature alteration was unexpected based on spacecraft observations which indicated that Ryugu’s surface may be thermally altered. Here we show that sulfides in a single particle (A0016) returned by the Hayabusa2 mission are unlike any previously described from Ryugu. The presence and compositions of violarite, pyrite, chalcopyrite, pentlandite, and Fe-depleted pyrrhotite grains provide direct evidence for hydrothermal alteration between 230 to 400 °C under highly oxidizing and acidic fluid conditions. We hypothesize that A0016 was near to the site of a large impact that disrupted Ryugu’s precursor parent body. A Ryugu sample shows hydrothermal alteration (230–400 °C), linking returned material to Hayabusa2 spectral data and supporting Ryugu’s formation via a disruptive impact event, bridging spacecraft and sample observations.

Aerospace aluminum alloy is the most used structural material for rockets, aircraft, spacecraft, and space stations. The deterioration of surface integrity of dry machining and the insufficient heat transfer capacity of minimal quantity lubrication have become the bottleneck of lubrication and heat dissipation of aerospace aluminum alloy. However, the excellent thermal conductivity and tribological properties of nanofluids are expected to fill this gap. The traditional milling force models are mainly based on empirical models and finite element simulations, which are insufficient to guide industrial manufacturing. In this study, the milling force of the integral end milling cutter is deduced by force analysis of the milling cutter element and numerical simulation. The instantaneous milling force model of the integral end milling cutter is established under the condition of dry and nanofluid minimal quantity lubrication (NMQL) based on the dual mechanism of the shear effect on the rake face of the milling cutter and the plow cutting effect on the flank surface. A single factor experiment is designed to introduce NMQL and the milling feed factor into the instantaneous milling force coefficient. The average absolute errors in the prediction of milling forces for the NMQL are 13.3%, 2.3%, and 7.6% in the x-, y-, and z-direction, respectively. Compared with the milling forces obtained by dry milling, those by NMQL decrease by 21.4%, 17.7%, and 18.5% in the x-, y-, and z-direction, respectively.

In-orbit spacecraft, particularly those engaged in deep space exploration, face significant challenges to operational lifespan and reliability due to the complex and dynamic space radiation environment. While prior research has primarily addressed the effects of low-energy electrons, high-energy electrons pose a greater threat because they can penetrate spacecraft shielding and generate X-rays that endanger sensitive electronic components. To address this concern, this study establishes equivalent models of common spacecraft materials and investigates their X-ray generation characteristics under high-energy electron irradiation. The relative shielding effectiveness of metallic materials is also compared. Systematic simulation analysis quantifies the relationships between material properties and the resulting X-ray energy spectra and doses. The results demonstrate differences in the protective performance of various materials, providing a foundation for risk assessment related to high-energy electron radiation in space.

Hypervelocity impacts on spacecraft surfaces produce a wide range of effects including transient plasma clouds, surface material ablation, and for some impacts, the liberation of spacecraft material as debris clouds. This study examines debris-producing impacts on the Parker Solar Probe spacecraft as it traverses the densest part of the zodiacal cloud: the inner heliosphere. Hypervelocity impacts by interplanetary dust grains on the spacecraft that produce debris clouds are identified and examined. Impact-generated plasma and debris strongly perturb the near-spacecraft environment, producing distinct signals on electric, magnetic, and imaging sensors, as well as anomolous behavior of the star tracker cameras used for attitude determination. From these data, the spatial distribution, mass, and velocity of impactors that produce debris clouds are estimated. Debris-cloud expansion velocity and debris fragment sizes are constrained by the observational data, and long-duration electric potential perturbations caused by debris clouds are reported, along with a hypothesis for their creation. Impact-generated plasma-cloud expansion velocities, as well as pickup acceleration by the solar wind and driven plasma waves are also measured. Together, these observations produce a comprehensive picture of near-spacecraft environmental perturbations in the aftermath of a hypervelocity impact.

We report on the detection of the Brightest Of All Time (the BOAT) gamma-ray burst (GRB) 221009A by the MAVEN Solar Energetic Particle (SEP) silicon (Si) detectors. The SEP instrument on board the MAVEN spacecraft at Mars is designed to measure charged particle fluxes and energies. In this work, we show that the SEP Si detectors have detected populations of secondary charged particles and low-energy primary photons from the GRB. Our analysis relies on a series of simplified Geant4 Monte Carlo simulations. We show that electromagnetic and hadronic interactions between the GRB photons and the spacecraft’s passive material and Si detectors produced the detected secondary particles.

This review explores the applications of density functional theory (DFT) in materials design and how DFT has revolutionized materials discovery for various fields, including drug delivery, energy storage, and spacecraft coatings. The science mapping analysis identifies research trends, and the dominant countries leading the development of new materials for future advancements are reviewed. Fluorescent and localized materials for cancer treatment, thin films for energy storage, catalysts, and materials resistant to spacecraft, efficient energy storage, powerful catalysts, and more reliable spacecraft coatings for future exploration and research are discussed. We found that the strongest research growth was mainly demonstrated by the United States due to its research capabilities, funding, active collaboration, and emphasis on innovation in the design of new materials for various applications.