一种图像辅助火星着陆段自主导航方法

针对未来深空探测软着陆高精度实时导航的需求,提出了一种图像辅助的自主导航方案。首先通过下降段图像与落点区域地形匹配,获得着陆器相对于落点的位置和姿态;然后基于误差Kalman模型估计着陆器的状态误差,修正惯性导航的结果;在图像信息不可用的情况下,只进行惯性递推导航;这种方案既提高了导航的精度,也能保证实时性的要求。 数值仿真验证了该方案的可行性,该方案对未来实际工程任务具有很大的参考价值。     

火星探测器进入阶段稳定性分析

文章针对＂火星探路者＂,对火星探测器在进入火星大气减速过程中的运动稳定性问题进行了研究,分析了质心位置、进入条件、大气参数等因素对火星探测器运动稳定性的影响。分析结果表明,在马赫数大于1.2时,探测器处于一个比较稳定的状态。     

天问一号探测器高动态着陆惯导系统设计与试验

考虑到火星探测任务着陆过程动态变化大,稀薄大气环境下开伞会对探测器产生剧烈晃动,为此天问一号探测器研制了一套高动态着陆惯导系统,从硬件产品、使用时序到导航算法方面均进行了针对性设计,以适应着陆过程中的高动态环境.此外,为验证天问一号探测器高动态着陆惯导系统的性能,设计了模拟火星开伞工况的火箭弹高空开伞试验,结果表明该高...     

Gravitational wave detection on the Moon and the moons of Mars

The Moon and the moons of Mars should be extremely quiet seismically and could therefore become sensitive gravitational wave detectors, if instrumented properly. Highly sensitive displacement sensors could be deployed on these planetary bodies to monitor the motion induced by gravitational waves. A superconducting displacement sensor with a 10-kg test mass cooled to 2 K will have an intrinsic instrument noise of 10⁻¹⁶ m Hz^−1/2. These sensors could be tuned to the lowest two quadrupole modes of the body or operated as a wideband detector below its fundamental mode. An interesting frequency range is 0.1–1 Hz, which will be missed by both the ground detectors on the Earth and LISA and would be the best window for searching for stochastic background gravitational waves. Phobos and Deimos have their lowest quadrupole modes at 0.2–0.3 Hz and could offer a sensitivity h_min ? 10⁻²² Hz^−1/2 within their resonance peaks, which is within two orders of magnitude from the goal of the Big Bang Observer (BBO). The lunar and Martian moon detectors would detect many interesting foreground sources in a new frequency window and could serve as a valuable precursor for BBO.     

Development of a gas chromatography compatible Sample Processing System (SPS) for the in-situ analysis of refractory organic matter in martian soil: preliminary results

In the frame of the 2009 Mars Science Laboratory (MSL) mission a new sample preparation system (SPS) compatible with gas chromatography–mass spectrometry (GC–MS) has been developed for the in situ analysis of complex organic molecules in the Martian soil. The goal is to detect, if they exist, some of the key compounds that play an important role in life on Earth including carboxylic acids, amino acids and nucleobases.     

Comparative assessment of human–Mars-mission technologies and architectures

We compare a variety of mission scenarios to assess the strengths and weaknesses of options for Mars exploration. The mission design space is modeled along two dimensions: trajectory architectures and propulsion system technologies. We examine direct, semi-direct, stop-over, semi-cycler, and cycler architectures, and we include electric propulsion, nuclear thermal rockets, methane and oxygen production on Mars, Mars water excavation, aerocapture, and reusable propulsion systems in our technology assessment. The mission sensitivity to crew size, vehicle masses, and crew travel time is also examined. Many different combinations of technologies and architectures are applied to the same Mars mission to determine which combinations provide the greatest potential reduction in the injected mass to LEO. We approximate the technology readiness level of a mission to rank development risk, but omit development cost and time calculations in our assessment. It is found that Earth–Mars semi-cyclers and cyclers require the least injected mass to LEO of any architecture and that the discovery of accessible water on Mars has the most dramatic effect on the evolution of Mars exploration.     

美国新型载人火星探测技术方案

文章概括介绍了＂发现号＂宇宙飞船的布局结构。然后详细介绍了飞船用于火星探测的两种着陆舱的具体设计方案以及载人火星探测的任务剖面。最后分析了＂发现号＂宇宙飞船火星探测方案的关键可行技术和诸多设计优点。     

“凤凰号”火星探测器着陆过程

文章主要介绍了＂凤凰号＂火星着陆器的着陆过程、着陆点选择方法原则、巡航阶段工作任务,对进入（Entry）、下降（Descent）和着陆（Landing）即EDL阶段的蒙特卡罗分析结果和飞行器重建数值结果进行了总结比较。并对＂凤凰号＂相关的经验和教训进行了比较总结,这对中国未来的火星探测以及其他深空探测具有一定的借鉴作用。     

Human response to high-background radiation environments on Earth and in space

The main long-term objective of the space exploration program is the colonization of the planets of the Solar System. The high cosmic radiation equivalent dose rate represents an inescapable problem for the safe establishment of permanent human settlements on these planets. The unshielded equivalent dose rate on Mars ranges between 100 and 200 mSv/year, depending on the Solar cycle and altitude, and can reach values as high as 360 mSv/year on the Moon. The average annual effective dose on Earth is about 3 mSv, nearly 85% of which comes from natural background radiation, reduced to less than 1 mSv if man-made sources and the internal exposure to Rn daughters are excluded. However, some areas on Earth display anomalously high levels of background radiation, as is the case with thorium-rich monazite bearing sand deposits where values 200–400 times higher than the world average can be found. About 2% of the world’s population live above 3 km and receive a disproportionate 10% of the annual effective collective dose due to cosmic radiation, with a net contribution to effective dose by the neutron component which is 3–4 fold that at sea level. Thus far, epidemiological studies have failed to show any adverse health effects in the populations living in these terrestrial high-background radiation areas (HBRA), which provide an unique opportunity to study the health implications of an environment that, as closely as possibly achievable on Earth, resembles the chronic exposure of future space colonists to higher-than-normal levels of ionizing radiation. Chromosomal aberrations in the peripheral blood lymphocytes from the HBRA residents have been measured in several studies because chromosomal damage represents an early biomarker of cancer risk. Similar cytogenetic studies have been recently performed in a cohort of astronauts involved in single or repeated space flights over many years. The cytogenetic findings in populations exposed to high dose-rate background radiation on Earth or in space will be discussed.     

火星探测用降落伞研制试验简介

文章主要介绍了美国火星探测用降落伞研制过程以及在研制过程中的一些主要试验,并同时指出了试验中的一些特点。