Showing papers in "Acta Astronautica in 2017"

TL;DR: A survey of propulsion systems for CubeSats can be found in this article, where propulsion systems that have been designed specifically for the CubeSat platform and systems that fit within CubeSat constraints but were developed for other platforms.

TL;DR: An overview of the planned OneWeb constellation setup is given and the characteristics of hypothetical OneWeb satellite fragmentation clouds are described and the impact of collision clouds from OneWeb satellites on the constellation itself is analysed.

TL;DR: In this paper, the effects of micro air jets on mixing performances of cascaded hydrogen jets within a scramjet combustor were investigated by using the Reynolds-averaged Navier-Stokes equations with Menter's Shear Stress Transport (SST) turbulence model.

TL;DR: In this article, a three-dimensional numerical study has been performed to reveal the affects of micro air jet on mixing of the hydrogen jet in a Mach 4.0 crossflow with a global equivalence ratio of 0.5.

TL;DR: Four critical deployment parameters of tethered-net, namely maximum net area, deployment time, traveling distance and effective period are identified, and the influence of initial deployment conditions on these four parameters is investigated.

TL;DR: In this article, the authors focus on the three best-documented water oceans beyond Earth: those within Europa, Titan and Enceladus, and suggest that the search for life on these oceans can also be accomplished quickly by the standards of outer solar system exploration.

TL;DR: In this article, mechanical properties of structures with triply periodic minimal surface (TPMS) topology were investigated using plastic prototypes made of polylactic acid by 3D-printing process.

TL;DR: In this paper, a 3D transient mathematical model of chemically reacting gas mixture flows incorporating hydrogen air mixtures was developed to study detonation initiation due to focusing of a shock wave reflected inside a cone.

TL;DR: In this paper, the adaptive unscented Kalman filter was used to improve the tracking speed of the adaptive attitude control system by systematically adapting the covariance matrix to the faulty estimates using innovation and residual sequences.

TL;DR: In this paper, a review of the trends in Earth observation (EO) and the possible impacts on markets of the new initiatives, launched either by existing providers of EO data or by new players, privately funded.

TL;DR: In this paper, the flow fields around a blunt cone with and without aerodisk flying at hypersonic Mach numbers are computed numerically, and the numerical simulations are conducted by specifying the freestream velocity, static pressure and static temperatures at the inlet of the computational domain with a three-dimensional, steady, Reynolds-averaged Navier-Stokes equation.

TL;DR: In this paper, the aerothermoelastic flutter and buckling instabilities of functionally graded carbon nanotube reinforced composite (FG-CNTRC) cylindrical shell under simultaneous actions of aerodynamic loading and elevated temperature conditions are investigated.

TL;DR: In this paper, numerical results for a Rotating Detonation (RD) propagating in a layer of combustible mixture, created by injection of gaseous hydrogen and oxygen, are presented.

TL;DR: In this paper, a loosely coupled fluid-thermal analysis is performed to illustrate the thermal response of different configurations and the relevant flow field variation, and the results indicate that increases in spike diameter and length will result in a sharp decline of the wall temperature along the spike, and overall heat flux is remarkably reduced to less than 300 W/cm2 with the aerodome mounted at the spike tip.

TL;DR: In this article, a new model of aluminum agglomeration on the burning surface of composite propellants is derived to predict the particulates size distribution with a low computational amount.

TL;DR: In this paper, a 6-step Jones-Lindstedt mechanism with an eddy-dissipation concept model was used for turbulent kinetic reaction in bipropellant applications.

TL;DR: A methodology for estimating the position and orientation of a rocket body in orbit – the target – undergoing a roto-translational motion, with respect to a chaser spacecraft, whose task is to match the target dynamics for a safe rendezvous.

TL;DR: A review of emerging micropropulsion technologies and evaluates their applicability to microsatellite missions in the altitude range 250–500 km, demonstrating their results on two different remote sensing applications.

TL;DR: In this paper, a dual transverse injection system with a front hydrogen porthole and a rear air pothole arranged in tandem is proposed, and this is a realistic approach for mixing enhancement and penetration improvement of a scramjet combustor.

TL;DR: In this article, a series of numerical simulations of RDE modeling real injection nozzles with different exit widths are performed, and the effects of nozzle exit width on chamber inlet state, plenum flowfield and detonation propagation are analyzed.

TL;DR: In this paper, a multiphase convex programming approach for rapid reentry trajectory generation that satisfies path, waypoint and no-fly zone (NFZ) constraints on Common Aerial Vehicles (CAVs) is proposed.

TL;DR: In this paper, the authors describe the flow field around a hemispherical nose cylinder with a new combination of spike and counterflow jet at free stream of Mach number of 6. In this numerical analysis, axisymmetric Reynolds-averaged Navier-Stokes equations was solved by k-ω (SST) turbulence model.

TL;DR: In this paper, a smoothed particle hydrodynamics method was used to simulate the hypervelocity impact of a spherical projectile with a thin plate and comparison with experimental data, which showed that in case of the cube sharp edge impact, a debris cloud of a higher density, and therefore most dangerous for the considered systems of two plates, is formed.

TL;DR: In this article, the attitude motion of a satellite equipped with a magnetic control system is considered and three-axis attitude is analyzed numerically with advanced assumptions: inertia tensor uncertainty, disturbances of unknown nature, magnetometer errors are taken into account.

TL;DR: In this article, a coordinated stabilization scenario is introduced to reduce the angular momentum, which has two stages, Momentum Reduction and Momentum Redistribution, for a non-cooperative target with large inertia grasped by a space robot.

TL;DR: In this paper, a nonlinear guidance algorithm for both hovering and landing of an asteroid is proposed, which achieves its target position and velocity in finite-time without the requirement of reference trajectories.

TL;DR: In this paper, the thermal design and analysis of a 1-km, gigawatt-level transmitting antenna in SSPS were investigated based on the three SSPS concepts, and the thermal characteristics of each SSPS concept were compared.