Missions to near-Earth objects (NEOs) are key destinations in NASA's new "Flexible Path" approach. NEOs are also of interest for science, for the hazards they pose, and for their resources. We emphasize the importance of ultra-low delta-v from LEO to NEO rendezvous as a target selection criterion, as this choice can greatly increase the payload to the NEO. Few such ultra-low delta-v NEOs are currently known; only 65 of the 6699 known NEOs (March2010) have delta-v <4.5 km/s, 2/3 of typical LEO-NEO delta-v. Even these are small and hard to recover. Other criteria - short transit times, long launch windows, a robust abort capability, and a safe environment for proximity operations - will further limit the list of accessible objects. Potentially there are at least an order of magnitude more ultra-low delta v NEOs but, to find them all on a short enough timescale (before 2025) requires a dedicated survey in the optical or mid-IR, optimally from a Venus-like orbit because of the short synodic period for NEOs in that orbit, plus long arc determination of their orbits.
Sample return from the near-Earth asteroid known as 25143 Itokawa was conducted as part of the Hayabusa mission, with a large number of scientific findings being derived from the returned samples. Following the Hayabusa mission, Hayabusa2 was planned, targeting sample return from a primitive asteroid. The primary target body of Hayabusa2 was asteroid 162173 Ryugu; however, it was also necessary to gather physical information for backup target selection. Therefore, we examined five asteroids spectroscopically, 43 asteroids spectrophotometrically, and 41 asteroids through periodic analysis. Henc…
An investigation of the low-DeltaV near-Earth asteroids (341843) 2008 EV5 and (52381) 1993 HA. Two suitable targets for the ARM and MarcoPolo-M5 space missions
美国宇航局正在开发的小行星重定向任务（ARM）计划从近地小行星（NEA）收集一块数米巨石，并在2020年中期将其带到顺月空间，供未来的研究和利用。2016年，欧洲航天局提出了M5任务机会的MarcoPolo-M5项目，从一个非常原始的D型近地小行星带回样本。我们的目标是进一步表征样品返回空间任务的两个最佳目标的物理特性，低Δ V NEAs（341843）2008 EV 5和（52381）1993 HA。2008 EV 5是ARM的基线目标，但文献中只有一个该对象的光谱。1993年HA是一个非常有利的目标，为空间飞行任务的基础上，其动力学特性：在这里，我们打算评估它是否是一个合适的目标，为马可波罗-M5。我们在ESO-VLT用FORS 2仪器获得了2008 EV 5在不同旋转相位的可见光谱。我们还获得了可见光和近红外光谱的1993 HA，使用EFOSC 2和SOfI仪器在ESO-NTT。1993年HA的可见光光度测定是在Itaparica Sertao天文台（巴西）的IMPACTON项目范围内进行的。我们的新观测结果与2008年EV 5的C型分类一致。我们获得了五个可见光谱，没有显示出任何变化的范围内的噪音，这表明一个均匀的表面。我们获得了1993年HA的第一个光谱数据集，发现了D型典型的无特征的红色倾斜行为。我们发现1993 HA的会合自转周期为4.107 ± 0.002小时。导出…
一个简单的形式主义，以评估有多少小行星含有矿石，即商业上有利可图的材料，而不仅仅是一个高浓度的资源。我应用这种形式主义的两个资源的情况下：铂族金属（PGMs）和水。假设现在只有镍铁小行星对铂族金属感兴趣，那么1%的近地天体富含铂族金属。由于缺乏直径大于100米的超低δ-v（<4.5 km s-1）近地天体，含矿比例降至每2000个近地天体中只有约1个。由于直径100米的近地天体的价值需要超过10亿美元，而直径大于100米的近地天体数量约为20，000个（Mainzer等人，2011年），因此含铂族金属矿的近地天体总数约为10个。我强调，这是一个保守和高度不确定的值。例如，如果delta-v可高达5.7 km s-1，则含铂族金属矿的近地天体的数量级会增加一个数量级。在空间利用的水矿石可能在约1/1100的近地天体中发现。直径小至18米的近地天体也可能是水-矿体，因为预计约25%的碳质小行星中含有丰富的水（约20%），使1 000万个这种大小的近地天体中含有水-矿体的近地天体达到约9 000个。然而，这些小型近地天体在目前的调查中很难找到。将有约18个直径大于100米的含水含矿近地天体。这些估计目前非常不精确，对微小的变化很敏感，特别是在允许的最大delta-v中。尽管如此，这里发现的低值意味着迫切需要对形式主义的每一项进行更好的确定。如果经过更好的估计仍然发现少量含矿近地天体，那么…
This paper examines the effectiveness of an asteroid exploration architecture comprised of multiple nanosatellite sized spacecraft deployed from a single mother ship into a heliocentric orbit in the main asteroid belt where the mothership is ideally located in region of high density. Basic mission requirements associated with a Mother-Daughter architecture are established utilizing a relatively large number (10-20) daughter spacecraft distributed from a mothership within the asteroid belt for the purpose of executing sample and return missions. A number of trade analyses are performed to estab…
Discovery of 2 km ultra-fast rotating asteroid in Rubin DP2 catalog via varying Fourier order method
University of Washington（华盛顿大学）；Institute of Applied Astronomy of Russian Academy of Sciences（俄罗斯科学院应用天体物理研究所）；Department of Astronomy, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校天文学系）；Rubin Observatory/NSF NOIRLab（鲁宾天文台/美国国家光学红外天文实验室）
Near-Earth small-body mission targets 162173 Ryugu, 101955 Bennu, and 25143 Itokawa produce gravity fields around 4 orders of magnitude below that of Earth and their irregular shapes, combined with rotational effects produce varying surface potentials. Still, we observe familiar geologic textures and landforms that are the result of the granular physical processes that take place on their surfaces. The nature of these landforms, however, their origins, and how these surfaces react to interrogation by probes, landers, rovers, and penetrators, remain largely unknown, and therefore landing on an …
(modified from published version) Twelve years ago the Catalina Sky Survey discovered Earth's first known natural geocentric object other than the Moon, a few-meter diameter asteroid designated 2006 RH120. Despite significant improvements in ground-based telescope and detector technology in the past decade the asteroid surveys have not discovered another temporarily-captured orbiter (TCO; colloquially known as minimoons). Within a few years the Large Synoptic Survey Telescope (LSST) will either begin to regularly detect TCOs or force a re-analysis of the creation and dynamical evolution of sma…
Tianwen-2 target asteroid (469219) Kamo'oalewa probably develops an Itokawa-compositional but ultra-highly space-weathered surface
Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences（中国科学院地球化学研究所）；State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology（澳门科技大学）；School of Earth Sciences, China University of Geosciences（中国地质大学）；Department of Physics, University of Helsinki（赫尔辛基大学）；Asteroid Engineering Laboratory, LuleåUniversity of Technology（鲁勒技术大学）；Institute of applied physics "Nello Carrara", Sesto Fiorentino（内洛·卡拉拉应用物理研究所）；Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；Department of Earth and Planetary Science, The University of Tokyo（东京大学）；Aix Marseille Université, CNRS, CNES, Laboratoire d’Astrophysique de Marseille（马赛大学）；Department of Geological Sciences, Brown University（布朗大学）；Department of Geography, University of Winnipeg（温尼伯大学）；Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology（麻省理工学院）；UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d'Astrophysique de Grenoble（格勒诺布尔行星与天体物理研究所）；Institute of Astronomy, National Central University（中央大学）；ESA ESRIN/PDO/NEO Coordination Centre（欧洲航天局地球观测中心近地天体协调中心）；Elecnor Deimos（埃莱科诺尔戴莫斯）；School of Engineering, Guangzhou College of Technology and Business（广州工商学院）；European Southern Observatory (ESO)（欧洲南方天文台）；Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Institute of Systems Engineering（重庆大学）；Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Institute of Space Sciences, Shandong University（山东大学）
Radiolocation methods of probing minor celestial bodies (asteroids) by the nanosecond pulses can be used for monitoring of near-Earth space with the purpose of identification of hazardous cosmic objects able to impact the Earth. Development of the methods that allow to improve accuracy of determining the asteroids size (i.e. whether it measures tens or hundreds meters in diameter) is important for correctly estimating the degree of damage which they can cause (either regional or global catastrophes, respectively). In this paper we suggest a novel method of estimating the sizes of the passive c…
The exploration of small body asteroids provides direct access to the primitive building blocks of our solar system. Sample and return missions enable chemical and radioisotope studies which not only provide evidence for the formation of the solar system, but also a basic understanding of where resources might be found for future exploitation. The touch-down and sample techniques established by Hayabusa-2 and OSIRIS-REx accomplish this mission by physically touching down on the asteroid and collecting samples into a basket extended via a probe from the bottom of the spacecraft. This technique …
Composition of Near-Earth Asteroid 2008 EV5: Potential target for Robotic and Human Exploration
我们在可见光（0.30-0.92微米）和近红外（0.75-2.5微米）波长下观察了潜在危险的小行星（PHA）2008 EV 5，以确定其表面成分。这颗小行星特别令人感兴趣，因为它是两个样本返回任务提案（马可波罗-R和隼鸟-2）和人类探索的潜在目标，因为它的低delta-v交会。2008 EV 5的光谱除了一个0.48微米的弱自旋禁戒Fe 3+吸收带外，基本上没有什么特征。光谱也有一个整体的蓝色斜率。2008年EV 5的最大值仍然不确定，根据热模型，下限为0.05，上限为0.20。Busch等人（2011年）估计的0.12与我们的热建模结果一致。2008年EV 5的基因组和组成也与C型分类学分类一致（Somers等人，2008年）。最佳光谱匹配是与类似于Orgueil的Cl碳质方解石，其也具有弱的0.48微米特征和整体蓝色斜率。这个0.48微米的特征也可以在磁铁矿的光谱中看到。CI卫星的最大值是我们对2008年EV 5最大值的估计范围的下限。
