Owing to the chaotic and non-integrable nature of three-body dynamics, the conventional Keplerian elements are rendered inadequate for cataloging cislunar space objects. Currently, there has been a conspicuous absence of universally recognized parameters for the characterization and cataloging of such objects, posing a significant impediment to effective cislunar space situational awareness. This research published in the Chinese Journal of Aeronautics proposes a novel approach to parameterize the orbits of the Earth-Moon collinear libration points by leveraging the theoretical frameworks of canonical transformations. Six characteristic parameters are established, which maintain a bijective correspondence with the state variables. Specifically, two parameters define the motion of the invariant manifold, while the remaining four parameters characterize the dynamics of the central manifold. Based on the parameters of central manifold, a situation map for depicting the distribution of libration point objects was developed, and its application in orbit identification was explored. This method furnishes novel instrumentation for enhanced space situational awareness and target cataloguing within the cislunar domain, enabling operators to effectively tag, track and manage cislunar objects with a compact, uncertainty-quantified parameter set.

A research team from the Beijing Institute of Technology (BIT) and Yinhe Hangtian has achieved a major advance in orbit mechanics by developing an analytical method capable of directly predicting spacecraft trajectories under third-body gravitational perturbations. This work, recently published in the Chinese Journal of Aeronautics, resolves a long-standing challenge in celestial dynamics and provides a new theoretical tool for deep-space exploration and autonomous spacecraft control.

The wide-speed-range vehicles have attracted significant attention due to the exceptional performance in autonomous aerospace operations. In a recent innovative study published in the Chinese Journal of Aeronautics, a double swept waverider employing novel vortex-wave coupling technology has addressed the fundamental compromise between high-speed shockwave management and low-speed vortex lift utilization. By integrating basic flow field design with an Improved Multi-Objective Cuckoo Search algorithm, this configuration achieves breakthrough wide-speed-range performance, laying a critical foundation for the development of horizontal take-off and landing aerospace vehicles.

 

The notion of employing detonation to enhance aerospace propulsion systems has been explored for several decades. In a recent breakthrough, a novel detonation engine known as the Ram-Rotor Detonation Engine has emerged. This innovative engine integrates the processes of propellant compression, detonation combustion, and expansion within a single rotor, enabling it to markedly enhance propulsion efficiency across a broad range of flight Mach numbers.

Kyoto, Japan -- What we know of the birth of a black hole has traditionally aligned with our perception of black holes themselves: dark, mysterious, and eerily quiet, despite their mass and influence. Stellar-mass black holes are born from the final gravitational collapse of massive stars several tens of the mass of our Sun which, unlike less massive stars, do not produce bright, supernova explosions.

Or at least, this is what astronomers had previously thought, because no one had observed in real time the collapse of a massive star leading to a supernova and forming a black hole. That is, until a team of researchers at Kyoto University reported their observations of SN 2022esa.

The Kyoto team had wondered whether all massive stars -- those that are at least 30 times the mass of the Sun -- die quietly without a supernova explosion, or if in some cases they are accompanied by an energetic and bright, special type of supernova explosion. The astronomers then discovered a type Ic-CSM class supernova that appeared to be an explosion of a Wolf-Rayet star, which are so incomprehensibly massive and luminous that astronomers believe them to be the progenitors of black hole formation.

A research team led by Prof. TIAN Hengci from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS) conducted extensive analysis of lunar basalts collected by Chang'e-6 (CE6) from the South Pole–Aitken (SPA) Basin. These samples exhibit significantly heavier potassium (K) isotopic compositions than all previously documented lunar basalts from the Apollo missions and lunar meteorites.