Advances in Astronautics Science and Technology最新文献

A novel photonics-based RF reception approach is proposed as a competitive solution to meet the current challenges of photonics-based approaches and to realize high performances at the same time. The proposed approach adopts the superheterodyne configuration by a combination manner of electronic techniques and photonic techniques, including the ultra-wideband generation of optical LO, the two-stage photonic superheterodyne frequency conversion and the real-time IF compensation. An engineering prototype has been developed and its performance has been evaluated in the laboratory environment. The experiment results preliminarily verify the feasibility of the proposed approach and its engineering potential. The typical performances are as follows: 0.1 GHz ~ 45 GHz operation spectrum range (> 40 GHz), 900 MHz instantaneous bandwidth, 101 dB·Hz^2/3 SFDR and 130 dB·Hz LDR, image rejections of ~ 80 dB for 1st frequency conversion and > 90 dB for 2nd frequency conversion.

Facing the major scientific issues of the global carbon cycle and the monitoring demand for carbon emission reduction all over the world, this paper researches and develops a new calculation method for space-based remote sensing detection of greenhouse gas-flux based on the atmospheric boundary layer turbulence transport theory and the active detection of coherent differential absorption lidar system. By obtaining the atmospheric wind profile information, gas concentration profile information and the new calculation method for space-based gas-flux proposed in this paper, the near-surface gas-flux information in the detected area can be directly obtained. So it can innovatively realize the space-based active and direct remote sensing of the atmospheric boundary layer gas-flux. The method in this paper not only can make up the blank in the space-based active detection of greenhouse gas-flux, but also can realize the high spatial and temporal resolution measurement of the three-dimensional atmospheric motion. It reduces assumptions and errors of the existing model based on the column concentration assimilation inversion method, so it can realize a direct and active observation of global multi-scale, high-quality, long-sequence gas-flux.

The rapid development of space technology has made it increasingly important to use space robots for on-orbit services. Space crawling robots can perform extravehicular condition monitoring, spacecraft fault location and diagnosis, repair and maintenance by carrying different payloads and traversing the spacecraft surface, which has received wide attention from researchers. A prototype of space crawling robot has been designed in this work, which is a quadrupedal insect-like configuration with integrated bionic adhesion material on the bottom of the four feet, and can walk on the satellite surface in a gravity-free space environment. The design and implementation of the crawling robot control system is carried out based on Robot Operating System, including hardware system construction and software architecture design. The tripod gait was also designed to enable the robot to crawl more stably in space. At last, the basic capabilities of the designed space crawling robot are tested in the ground environment, and the results demonstrate the robot’s body control capability, omnidirectional walking capability, and obstacle crossing and avoidance capability.

BSPIF-S-7.5A, a kind of open cell and low-density polyimide foam was developed for Chinese satellite. The polyimide foam is thermal isolation material with low thermal conductivity and high glass transition temperature. Basic physical properties, thermal physical properties, mechanical properties have been studied. For validating space environment resistance of polyimide foam, outgassing in vacuum, thermal cycle, total dose radiation, thermal vacuum and atomic oxygen tests have been performed. The apparent core density of this foam is as low as 7.5 ± 0.5 kg m⁻³. Its volume percentage of open cells is over 98%, which is beneficial to outgas in orbit. Coefficient of thermal expansion is less than 40 × 10^–6 K⁻¹ in the temperature range from − 170 to 135 ℃. Thermal conductivity in vacuum increases from 2.7 to 42.3 mW (m K)⁻¹ with temperature rising from – 130 to 135 ℃. After severe space environment tests, thermal conductivity becomes even lower, compressive strength raises slightly, but shear property declines apparently. Covered with polyimide film, polyimide foam can resist atomic oxygen erosion effectively. Therefore, the polyimide foam is superior thermal insulation material for space application, which is ideal for satellite structure.

To design a gigantic microwave power transmitting array for space solar power station, modular design procedure is discussed. Besides microwave power channels, radiating array and thermal control, functions such as DC power source and beam steering should also be included in the design of the microwave power transmitting array. Smart composite structures integrate electronics, structures, thermal control and other functions into a module, providing an advanced design and integration paradigm. Modular smart composite structure antenna is an ideal candidate for its light weight and other performance.

Laser wireless power transmission (LWPT) is one of the effective ways to provide long-distance convenient and perpetual energy supplies to electronics. Especially in space power satellite (SPS), LWPT can be used to transfer energy not only to ground, but also to other spacecrafts, which applied for satellite rescuing, spacecraft maintaining in orbit. In space application, LWPT system has characteristics of long distance, higher power, precisely aiming accuracy and better adaptability to space environment. In this paper, we propose a long distance LWPT system in SPS. Firstly the system diagram, composition and key technologies are described, which include the selection of laser, the collimated and expanded module of laser beam, the principle of the optical-to-electrical conversion efficiency of InGaAs photovoltaic cell for the high intensity laser with different laser wavelengths, the Acquisition Pointing and Tracking (APT) system and the Maximum Power Point Tracking (MPPT) technology. Then the LWPT system in SPS is designed, which composed of laser transmitting subsystem, laser receiving subsystem, APT platform and energy managing subsystem. Finally, we evaluate the power conversion performance of LWPT by simulation, which illustrates that the system can achieve better energy transmission effect under the condition of transmission distance of 400 km (space to ground) and beam pointing accuracy of 5 μrad.

The INFANTE project is a public–private initiative arising from the experience of Portuguese companies and R&D institutes in developing critical subsystems for space missions over the last 20 years. Using such building blocks, TEKEVER leads a consortium of 20+ entities currently developing a technology demonstrator microsatellite for Earth Observation. This paper addresses a set of technical challenges faced in the conceptualization of a satellite-borne SAR, along with new project-level approaches within the framework of new space while managing a large consortium of partners.

The Solar Sail has been playing a major role in de-orbiting. It was introduced to deploy Sail which can open and close. The existing Solar Sail actuation is mostly based on the Origami model. This paper is about smart material implementation for robotic applications. The design and assembling of a mini version of the light Solar Sail have been developed here. The main task is to open and close the Solar Sail with basic control. The shape memory alloy (SMA) based linear actuator has been used for controlling the open and close operation of the Light Sail. The structural details of the light Solar Sail with SMA-based linear actuator have been demonstrated as well. The experimental study is about power requirements for the opening and closing operation of the light Solar Sail. It aims to obtain minimum power consumption for closing and opening the Solar Sail with SMA-based linear actuator. This kind of setup can be used further for real-time space exploration with a robust version.

The solar panels installed on a CubeSat are considered the main energy source of a nanosatellites. The deployment mechanism of a solar panel must be analyzed and tested extensively. Any suggested solar panel design should present a low vibrating free spinning deployment mechanism. This paper examines various types of solar panels to reach a conclusion of the efficient design when deployed on a 1U or 2U unit. However, calculations, analysis, simulations do not always give an extensive picture of how the satellite shall behave during deployment. Thus, testing in a microgravity environment gives a more accurate answer of how the satellite shall behave. In our work, various solar panels mechanisms are developed and eventually tested in microgravity. The first accordion structure for a 1U structure is tested in a microgravity environment through a parabolic flight with the National Research Council Falcon 20 aircraft. The results are recorded and analyzed to optimize the next design. The second design is based on a drag-sail mechanism for a 2U structure. The design is improved upon the first experiment results for the next parabolic flight. The simulated amount of power generated in orbit is also a main factor in our evaluation.