With heavy reusable launch vehicles becoming a key technology for low-cost and high-frequency space exploration, cable-net recovery schemes have attracted considerable attention due to their strong adaptability to landing dispersion and attitude deviations. However, under multiple sources of interference—including engine plume impingement, trolley motion, and flexible vibrations—the dynamic state information of the flexible cable-net recovery system is difficult to acquire directly, severely constraining the accuracy of closed-loop control and capture reliability. Although Kalman filtering combined with multibody dynamics models can achieve state estimation for complex systems, the flexible cable-net system is inherently a high-dimensional, nonlinear, strongly rigid-flexible coupled constrained multibody system, whose dynamic equations are formulated as index-3 differential-algebraic equations (DAEs). Conventional methods require the conversion of DAEs into ordinary differential equations (ODEs) followed by linearization, a process that is complex and lacks generality; conventional numerical integration methods converge slowly when dealing with such stiff problems, with the Jacobian matrix becoming severely ill-conditioned under large time steps and constraints being prone to violation. Therefore, developing a filtering method that does not require model transformation, can directly utilize the multibody DAE for state prediction, and can maintain constraint satisfaction has become a key technical challenge for state estimation in flexible cable-net recovery.

Apophis will make an extremely close flyby of Earth on April 13, 2029, at a distance of approximately 31,029 km—an event unprecedented for an asteroid of this size—providing a valuable natural experiment for studying tidal interactions, spin-state variations, and surface material migration between the asteroid and Earth. A large number of ground-based observations and space missions are expected to participate, but most observations will be concentrated from Earth's perspective, leaving observational blind spots as Apophis rapidly recedes from Earth's view after the flyby. LUMIO (Lunar Meteoroid Impacts Observer) is a 12U CubeSat of the European Space Agency, planned to be deployed in a quasi-halo orbit around the Earth–Moon L2 point; its primary mission is to observe meteoroid impact flashes on the lunar farside, with a launch expected in 2028. However, three critical questions remain unanswered: whether LUMIO-Cam—a camera designed for observing impact flashes—can detect Apophis as a sub-pixel target, whether it can resolve fluctuations in its light curve, and whether it can observe for a sufficiently long duration to obtain complete spin-period information.

India is the most populated country in the world and regularly experiences extreme heatwaves in the spring and summer. A recent study suggests that both natural and man-made aerosols in the atmosphere, combined with cloud cover, have mitigated the surface warming of the area compared to other landmasses.

With the accelerated advancement of lunar and Mars exploration programs, long-term human habitation on extraterrestrial bodies faces the severe challenge of extreme diurnal temperature variations. Phase change materials (PCMs), owing to their ability to store or release substantial latent heat during solid–liquid phase transitions while maintaining a nearly constant temperature, have become an ideal solution for space thermal control systems. However, in the microgravity environment of space, the ground-dominant natural convection tends to disappear, and thermocapillary convection may become the prevailing heat transfer mechanism; in low-gravity environments such as those on the Moon and Mars, the coexistence and competition between these two convective regimes remain unclear. Existing studies have predominantly focused on either Earth's gravity or pure microgravity conditions, with a notable scarcity of research on the coupled effects of thermocapillary and natural convection at intermediate gravity levels. The melting dynamics of two typical organic PCMs, succinonitrile and n-octadecane, under low-gravity conditions have not yet been systematically elucidated. Therefore, clarifying the roles of thermocapillary convection under varying gravity levels and container geometries holds significant engineering guidance for the design of efficient space thermal control systems.