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Rosetta probe trajectory toward the 67P/Churyumov–Gerasimenko and the main phases of the mission (ESA courtesy)
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Comets have been studied from a long time and are believed to preserve pristine materials, so they are fundamental to understand the origin of the solar system and life. Starting in the early 1990s, ESA decided to have a more risky and fantastic mission to a comet. As Planetary Cornerstone mission of the ESA Horizon 2000 program, the Rosetta missio...
Citations
... In 2004, the "Rosetta" vehicle developed by ESA flowed to the comet (Barucci & Fulchignoni, 2017;Taylor et al., 2017), which carried the sampler drill and distribution system (SD2), as shown in (Deng et al., 2021), (f) the SA/SPaH device on "curiosity," (g) rig on SA/SPaH system, (h) penetrator on ESA's ExoMars mission (Magnani et al., 2011), (i) SD2 drilling type automatic sampling mechanism, (j) microrover equipped with drilling subsystem, (k) drilling rig cutaway view, (l) planetary regolith sampling structure (Zhang et al., 2016). [Color figure can be viewed at wileyonlinelibrary.com] pair transmission, while motor A drives the hollow shaft to translate downward through ball screw transmission. ...
A planetary penetrator is a kind of machine that can use its special structure to independently penetrate an exoplanet and sample it for storage. It is a hot research topic in the world and has important development potential in the field of deep space exploration. Based on the analysis of relevant literature, this paper classifies and compares various representative planetary penetrator projectiles around the current research status. The development progress and key technologies of the planetary penetrator are analyzed, the current technical challenges are summarized, and the development trend of the planetary penetrator has prospected. The planetary probe has a broad application prospect, and its development will provide technical support for humans to establish extraterrestrial habitat, and play an important role in the field of deep space exploration. Currently, planetary penetrator research is still in its infancy, and the field is full of possibilities that need to be explored and improved.
... In order to recognise the relationship between comets and dark asteroids, such as D-types, one must have knowledge of the properties of both entities. We learned about comets from the Stardust [39] and Rosetta [40,41] space missions. In the future, we will have the contribution of the Comet Interceptor mission [42]. ...
... It will determine the volatile content, the porosity, and the effect of space weathering on the surface. Compositional and physical maps can be compared to data from ESA's Rosetta [41] and NASA's Lucy [64] missions. In particular, CARINA aims at searching for evidence of comet quenching. ...
D-type asteroids are among the most primitive small bodies of the solar system. Believed to be formed in the outer solar system, a minor fraction of these faint objects can be found in the near-Earth region. Some were suspected to be extinct comets disguised as asteroids. If D-type near-Earth asteroids could represent extinct comets, they would offer us a unique opportunity to investigate the relationship between two classes of minor bodies in our solar system. To provide new insights into D-type asteroids’ composition and dynamical evolution and the possible relation with comets, we introduce the mission concept CARINA (Comet Asteroid Relation INvestigation and Analysis). CARINA will visit and collect a sample from the asteroid 2002 AT4 and address key scientific questions related to our understanding of the early solar system evolution, and the origins of water and life on the early Earth. This paper outlines the scientific motivation and the means for the sample return. The spacecraft is equipped with a sampling ring to perform in-situ analysis and to collect, in a “touch and go” manner, samples from the surface and subsurface of the asteroid. A capsule is expected to return the samples to Earth in pristine conditions for detailed and extended analysis. These would represent a rare contribution to our meteorite collection since it would be the first time that material from a D class asteroid would be collected.
... La sonda espacial Rosetta de la Agencia Espacial Europea (ESA, por sus siglas en inglés), fue lanzada el año 2004 y tuvo una compleja trayectoria espacial, donde aprovechó la influencia gravitacional de Marte y la Tierra para llegar al cometa en noviembre del año 2014. Posteriormente desplegó un módulo de aterrizaje (Philae) sobre la superficie, para así poder estudiar la coma y el núcleo, caracterizando el gas, polvo, morfología y compuestos orgánicos (Barucci y Fulchignoni, 2017). ...
RESUMEN
La observación de los cometas se ha realizado desde hace miles de años y no ha dejado de ser una actividad importante hasta hoy. Al ser fenómenos aparentemente espontáneos y algunos tan vistosos como para ser observados a plena luz del día, han llegado a protagonizar antiguas mitologías, supersticiones, cuentos, poemas, pinturas, descubrimientos científicos y avances ingenieriles, entre muchas otras. En este trabajo se realiza un recuento de algunos cometas que han marcado la historia humana, mencionando desde el impacto social que han tenido, como en el caso de las discusiones epistémicas que generó el gran cometa de 1680, hasta algunos de los avances científicos más importantes que se han logrado con su estudio, tales como los aportes de Kepler y Newton a entendimiento de los movimientos orbitales de los objetos celestes, o los descubrimientos recientes de moléculas orgánicas importantes para la química prebiótica y el origen de la vida.
ABSTRACT
The observation of cometary bodies has been done since thousands of years ago and is a topic of great interest today. Amazing and spontaneous nature has led comets to influence multiple aspects of human societies: ancient mythologies, superstitions, stories, poems, paintings, scientific discoveries, engineering advances, etc. This work presents a detailed review of some comets that influenced human culture. We described their impact on society and some of the most important scientific advances in astronomy, physics, and chemistry for their remote and in situ analysis.
... The study of comets has advanced our knowledge about the formation of the solar system [1]. Previous comet exploring missions have studied Short Period Comets (SPCs), i.e., comets with an orbital period < 200 years: ICE performed a flyby of 21P/Giacobini-Zinner in 1985; Giotto visited the Halley comet in 1986 and 26P in 1990; in 2014, Rosetta notably met 67P/Churyumov-Geramisenko. The success of these and other missions to comets has returned large amounts of data that in 2020 is still generating new results on the field of cometary physics [2]. ...
... To address still unanswered questions with an improved methodology and incorporate state-of-the-art knowledge gained from the most recent cometary space mission Rosetta (Barucci and Fulchignoni et al 2017), a new research campaign dedicated to cometary physics was initiated in 2018. The international consortium CoPhyLab ('Comet Physics Laboratory'), in the framework of which this work was carried out, featured the development and construction of a highly specialized vacuum chamber by Kreuzig et al (2021). ...
A profound understanding of gas flow in porous media is of great interest for various technological and scientific fields. Its investigation by laboratory measurements, however, poses several challenges. In particular, the determination of macroscopic flow parameters from pressure and gas flow measurements is prone to various error influences, some of which are very difficult to analyze experimentally. Computer simulations are a solution in this context as they facilitate modifications of the underlying geometry and boundary conditions in a flexible way. Here we present a simulation framework for the analysis of a recent experiment for determining the Knudsen diffusion coefficient and viscous permeability of various porous granular materials. By combining the finite element method with analytical models and other numerical methods, we were able to identify previously neglected physical effects that increase the uncertainty of the measurements. In particular, the porosity increase due to finite sample dimensions, in a layer of about a grain diameter thickness near the container wall, creates a deviation of the measured pressure gradient. This deviation amounts to ca. 5% for a sample width of about 100 grains and a porosity of 0.5, and is indirectly proportional to the porosity. The second most prominent error source, the sample support sieve, causes a slight constriction of the flow volume. Simulations of this effect show an error around 4-7%, dependent on the grain size. Based on these findings we recommend an overall sample dimension of 100 grains or larger. As an example of failures of the sample homogeneity, we elaborate how channels through the sample influence the flow properties. Respective suggestions for keeping all discussed effects negligible are discussed in detail. Our methodology demonstrates how the combination of finite element computations with analytical representations of the involved macroscopic parameters can assess the validity and accuracy of laboratory experiments.
... In July 1996, at an altitude of about 660 km, a French satellite collided with a fragment of the third stage of the French Arian rocket. [30] In 2001, the ISS almost collided with a seven-kilogram instrument lost by American astronauts. Also, in October this year, the Mission Control Center postponed the station's orbit correction due to the danger of a new collision. ...
The research describes the effect of space debris on near-Earth space in order to reveal the concept of space debris composition and origin of debris, to determine the effect of space debris on space orbital flights by discussing the spatial distribution of debris, the Collisions of spacecraft with debris and their consequences, the probability of collisions of spacecraft with debris, and Measures to limit debris contamination of near-Earth space. Also, the expected consequences of debris contamination of space and the Earth have been identified in this research as the frequency of dangerous encounters between debris and vehicles will almost double. By 2059, this figure will quadruple. If we translate this prediction into absolute numbers, it turns out that in 2019 satellites and space debris converged 20 thousand times a week, and in 2059–50 thousand. Now the number of such events is about 13 thousand per week. The need to track hazards and ensure evasive maneuvers will significantly increase the cost of space missions. The research describes the ways to remove space debris from orbit by using jet propulsion devices (both high and low thrust), aerodynamic braking means, Collection of artificial objects using special spacecraft and their subsequent withdrawal, and using a solar sail.
... More globally, the two lobes are covered with dust, boulders of various sizes, lineaments, fractures, pits, depressions, and cliffs. Different kinds of regions (26 in total) have been identified and grouped into five basic categories [271]: dust-coating terrains showing signs of widespread mobilization and underlying consolidated units, brittle materials showing signs of mechanical failure and gradually evolving into talus-like deposits, large-scale depressions filled with boulders and talus debris, smooth terrains composed of non-cohesive materials thick enough to mask the underlying units and enclosed by consolidated rough units, and exposed strongly consolidated surfaces that have a rocky appearance and are cohesive enough to display lineaments and fractures. Regarding the coma, the Grain Impact Analyzer and Dust Accumulator (GIADA) and Micro-Imaging Dust Analysis System (MIDAS) onboard Rosetta found that most particles in the coma are compactly packed dust and some are even fluffy fractal aggregates (with a fractal dimension of 1.7 ± 0.1) of sub-micrometer monomers [272,273]. ...
Small bodies are among the best tracers of our Solar System’s history. A large number of space missions to small bodies (past and future) offer a unique opportunity to use these bodies as a natural laboratory to study the different processes, mechanical structures, and responses that drive the origin and evolution of small bodies, which are connected to the origin, evolution, and current architecture of the Solar System. Images of small bodies sent by spacecraft have revealed unexpectedly rich and complex geological worlds. In addition to very diverse compositions, small bodies in the Solar System have highly diverse shapes and structures, which reflect both different evolutionary paths and material properties. Furthermore, each individual body has diverse geological features on its surface, which include craters of various sizes and depths, boulders of different sizes and morphologies, lineaments, fractures, pits, signatures of landslides, terraces, and ridges. Such a geological richness could not be detected via ground-based observations, and we are still at the beginning of understanding their significance on the low-gravity surfaces on which they manifest. The combination of space mission data and numerical modeling allows us to enrich our understanding of the origin, evolution, and physical properties of these fascinating bodies. For instance, starting from the shape models, bulk densities, and spin rates determined from space mission data, we can investigate the formation mechanisms that lead to the observed properties of small bodies. We can also infer the interior and mechanical properties (e.g., friction and cohesion) that allow a small body to be structurally stable, as well as its further potential evolution under processes such as a spin rate increase or an impact. Then, considering the various processes that these bodies experience during their evolution, we can investigate how these processes modify their properties and, in turn, how those properties influence the outcome of these processes. This paper reviews our current knowledge of small-body shapes and structures and discusses the various processes that are responsible for their formation and evolution, which can modify the characteristics of the bodies. We separately consider each population of small bodies, although in some cases, such as active asteroids and comets, the distinction between two populations solely in terms of physical properties is not clear. We then summarize the main findings regarding the physical properties of small bodies that have been the target of rendezvous or sample return missions.
... Finally, a grain can be represented by a collection of dipoles when Discrete-Dipole Approximation (DDA) theory is used for light scattering calculations. Recent observations of the comet 67P/C-G by Rosetta showed the comet is rich in supervolatiles and the atmosphere of comet 67P/C-G showed that the comets are made of pristine materials synthesized in the solar nebula during the earlier stage of the solar system formation (Barucci et al., 2017). Huge advances in the cometary studiesleading to significant understanding of cometary dust propertieshave been made in the past decades with better observing techniques and with progress in modelling the presumed dust particle shapes. ...
In the present work, we propose a comparative study of optical properties in the visual spectral regime of porous dust particles having porosities ranging from 0% (compact particle) to 50% (as much matter as void in a same particle), generated using two different models considering particle as an ensemble of dipoles much smaller than wavelength. One of the models (the touching-dipoles model, named below: ‘‘TD model”) considers a homogeneous structure made up of touching dipoles (that is neighbouring); the dipoles are removed randomly one by one from a compact structure in such a way that the remaining structure is left connected. The other model (the non-touching-dipoles model, named below:’‘non-TD model”) generates porous particles by randomly removing dipoles without constraining the ensemble of dipoles to remain connected. The computations of the optical properties of these disordered particles are performed using Discrete Dipole Approximation (DDA) code. Linear polarization profiles and color (i.e. the ratio between the intensities of the light scattered by particles in the comet at 0.485 μm and 0.684 μm wavelengths expressed in log scale) curves are shown vs. the scattering angle, and compared for the two models at different porosities. The variation of scattering efficiency factor as a function of the size parameter (X) is also studied to point out sensitivity of light scattering to different pore structures (shape and size), comparing data from particles of same porosity but generated through different processes. The results are compared with Mie results where the effective refractive index for each porosity is calculated using Bruggemann mixing rule. It is observed that light scattering properties of the TD model is not much different from the EMT-Mie model, but the non-TD model differs significantly. These difference could be due to the fact that non-TD model contains a higher number of non-Rayleigh inclusions, as compared to the TD model.
... This indicates that these were two planetesimals formed independently before they merged in a low-velocity collision. The mission gave great insight into the formation of the comets in the Solar system, but also opened new questions that remain without an answer for now (Barucci & Fulchignoni, 2017). ...
Small bodies, like comets and asteroids, are of interest for the study of the origin of the Solar System since they have experienced little changes throughout time. Therefore, by understanding their evolution we can learn about the evolution of the Solar System itself. This information can be useful for future space exploration or for planetary defense. Nowadays, there are several space missions studying or about to study small bodies, but only a few instruments are destined to study the interior of small body cores.Radio waves interact with the medium they are propagating through and will undergo different modifications depending on the properties of the material. Therefore, radar is the ideal method to study the internal structure of an asteroid. The wave's properties, such as its velocity, will be affected by its travel through the nucleus dependent on the dielectric properties of the asteroid. We propose a new bi-static low-frequency radar (LFR) based on the instrument CONSERT which was onboard the Rosetta mission. This LFR primary objective is to measure the propagation delay between two electronics, one posed on the asteroid’s surface and the other orbiting around it. The signal will be transmitted through the body’s nucleus and will be affected by its composition and heterogeneity. By measuring different signal characteristics, such as the propagation delay, we can deduce the composition properties of the object.The main objective of this thesis is to study and understand how the clock drift between radar electronics will affect the measurement of the propagation delay in order to propose compensation methods to improve science return. The initial step of the thesis is to provide an understanding of the clock signal generation and how the stability of the signal will be affected over time by different processes like temperature, the voltage supply, or aging. To understand how these instabilities will impact the propagation delay measurement, we analyze the long scale drift of radar instruments. For this, we developed a time model of the radar based on time events. The model was used to build a simulator using a simple model of the clock signal generation. With this simulator, we show that the time errors have a different effect on the bi-static radar at different time scales, but that these different time scales are correlated. We propose a method to estimate clock drift from radar data to compensate for time errors.To validate the model, a test bench is designed and developed measuring time differences between two clocks. Using the test bench data as input for the simulator allows to estimate the impact on instrument performances and to estimate performances of the compensation methods. The data from the test bench is used for the validation of the selected clocks for the mission and will be used for their characterization. This clock characterization will help to improve the simulator for different tests, as we can include the real models for frequency instabilities.To conclude, we present the limitations of the compensation methods, as well as the improvements in the electronic design and operation of the instrument as a result of the time analysis.
... Comets and asteroids are of interest for a number of reasons: collisions with them have caused regional damage [1,2] and global catastrophes [3,4] in the past; they are seen as a potential source of raw materials for space-based economies [5]; and they offer a unique perspective on the solar system's formation and early composition [6]. ...
A number of missions to comets and asteroids have been undertaken by major space organizations driving a need to accurately characterize their gravitational fields. This is complicated however by their irregular shapes. To accurately and safely navigate spacecraft in these environments, a simple point-mass gravity model is insufficient and instead higher-fidelity models are required. Several such models exist for this purpose but all possess drawbacks. Moreover, there are some applications for which the currently available models are not particular well suited.
In this dissertation, numerical quadrature and curvilinear meshing techniques are applied to the small body gravity problem. The goal of this work is to to create a gravitational model suitable for integrating large numbers of low altitude trajectories and rapidly characterizing the near-surface potential field. In total three new models are developed. The first applies two-dimensional quadrature formulas to calculate the gravitational field of an arbitrary triangular surface mesh. The second extends this result to curvilinear surface meshes that more accurately approximate the surface topology. The third applies three-dimensional quadrature to curvilinear tetrahedral meshes to generate accurate distributions of point-masses. The accuracy of the new models is fully characterized and simple relations are presented for predicting the error of integrated trajectories. The efficiency of the models is then compared to other high-fidelity models currently in use. The new models perform well between the body’s circumsphere and a thin layer that surrounds the surface.
