In this work, we constructed a new model for the collisional evolution of the Main Asteroid Belt. Our goals are to test the scaling law from the work of Benz & Asphaug (1999) and ascertain if it can be used for the whole belt. We want to find initial size-frequency distributions (SFDs) for the considered six parts of the belt, and to verify if the number of asteroid families created during the simulation matches the number of observed families as well. We used new observational data from the WISE satellite (Masiero et al., 2011) to construct the observed SFDs. We simulated mutual collisions of asteroids with a modified Boulder code (Morbidelli et al., 2009), in which the results of hydrodynamic (SPH) simulations from the work of Durda et al. (2007) are included. Because material characteris- tics can affect breakups, we created two models - for monolithic asteroids and for rubble-piles (Benavidez et al., 2012). The results for monolithic and rubble- -pile asteroids are comparable and in both cases the number of created families is, within uncertainties, consistent with the observations. A disagreement of the SFDs for a limited size range D 1 to 5 km a is a good motivation to conduct new SPH simulations with relatively small targets. 1

No description available.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The Near Earth Asteroid Prospector (NEAP) has a scheduled launch date between mid- 1999 and mid-2000, and will encounter a yet to be determined near Earth asteroid (1.1 - 2.2 AU distance from Earth) some ten months later [2]. The purpose of this mission is not only to collect valuable scientific and geological data, but to also determine the value of the asteroid’s materials for possible mining and exploitation [2], [3]. The purpose of this paper is to detail frequency allocation issues and to determine possible return (space to Earth) data rates associated with deep space communications with the NEAP spacecraft.

This concept of calculating, optimizing, and utilizing a trajectory known as a ``Free Return Trajectory" to facilitate spacecraft rendezvous with Near-Earth Asteroids is presented in this dissertation. A Free Return Trajectory may be defined as a trajectory that begins and ends near the same point, relative to some central body, without performing any deterministic velocity maneuvers (i.e., no maneuvers are planned in a theoretical sense for the nominal mission to proceed). Free Return Trajectories have been utilized previously for other purposes in astrodynamics, but they have not been previously applied to the problem of Near-Earth Asteroid rendezvous. Presented here is a series of descriptions, algorithms, and results related to trajectory initial guess calculation and optimal trajectory convergence. First, Earth-centered Free Return Trajectories are described in a general manner, and these trajectories are classified into several families based on common characteristics. Next, these trajectories are used to automatically generate initial conditions in the three-body problem for the purpose of Near-Earth Asteroid rendezvous. For several bodies of interest, example initial conditions are automatically generated, and are subsequently converged, resulting in feasible, locally-optimal, round-trip trajectories to Near-Earth Asteroids utilizing Free Return Trajectories. Subsequently, a study is performed on using an unpowered flyby of the Moon to lower the overall DV cost for a nominal round-trip voyage to a Near-Earth Asteroid. Using the Moon is shown to appreciably decrease the overall mission cost. In creating the formulation and algorithms for the Lunar flyby problem, an initial guess routine for generic planetary and lunar flyby tours was developed. This continuation algorithm is presented next, and details a novel process by which ballistic trajectories in a simplistic two-body force model may be iteratively converged in progressively more realistic dynamical models until a final converged ballistic trajectory is found in a full-ephemeris, full-dynamics model. This procedure is useful for constructing interplanetary transfers and moon tours in a realistic dynamical framework; an interplanetary and an inter-moon example are both shown. To summarize, the material in this dissertation consists of: novel algorithms to compute Free Return Trajectories, and application of the concept to Near-Earth Asteroid rendezvous; demonstration of cost-savings by using a Lunar flyby; and a novel routine to transfer trajectories from a simplistic model to a more realistic dynamical representation. / text

Regardless of new mining technologies and environmental regulations, the minerals we extract from the earth’s crust will eventually run out. Likewise, our society demands a constant increase of technology to improve our quality of life. Mining in Zero Gravity is a speculative design project that offers a vision of our first attempt at mining platinum group metals from asteroids by the year 2040. Kolibri is designed within the boundaries of the future challenges facing the mining industry and the development of our space industry.

In the year of 2017 in October a strange object with a hyperbolic trajectory was observed in our solar system. There were several hypotheses that scientists used to try to explain what kind of an object it was, but no one could, according to the scientific community as a whole, perpetuate any of these explanations as accepted consensus. One of the scientists who had an interest in this object is Professor Avi Loeb at Harvard University. He wrote and published a popular scientific book called “Extraterrestrial”. In this book Loeb make quite a few arguments that are backing up his hypothesis that this object is no ordinary asteroid or comet, it is in fact a relic from an advanced, technological, alien civilization which originates from a solar system far away from our own. Many people in the scientific community have not accepted these views by Loeb and one of them is Jonathan I. Katz who challenges Loeb’s hypothesis directly. Loeb on the other hand believes that the general resistance to his views is founded in the usual conservatism and that many scientists are afraid to advocate for something like this and risk their credibility and careers. / I oktober 2017 blev ett intressant objekt observerat i vårt solsystem. Det presenterades flera olika hypoteser av forskare som försökte förklara vad för typ av objekt detta var men ingen av dessa kunde ena hela den vetenskapliga gemenskapen och ingen konsensus kunde således uppnås. En av vetenskapsmännen som uppvisade ett intresse för detta objekt är en professor från Harvard University vid namn Avi Loeb.  Han skrev en populärvetenskaplig bok som heter ”Utomjordiskt”. I denna bok presenterar Loeb flera argument som har som syfte att stärka hypotesen att detta inte är någon vanlig asteroid eller komet, det är en kvarleva från en avancerad, teknologisk, utomjordisk civilisation, som härstammar från ett solsystem långt ifrån vårt eget. Den här ståndpunkten som Loeb uppvisar har blivit utmanad av flera fysiker inom vetenskapsvärlden inte minst av astrofysikern Jonathan. I Katz. Själv menar Loeb att detta generella motstånd beror på gammal konservatism hos flera vetenskapsmän som inte vågar sticka ut hakan och således riskera att skada anseende såväl som karriär.

No description available.

In this thesis, we study how the planetary migration affects asteroid families. We identify the families among the Trojans of Jupiter by analysing their properties in the space of resonant elements, the size-frequency distribution and the colour indices. The previously reported number of families (10) seems to be overestimated, our analysis indicates that there is only one collisional family among Trojans with the parent-body size DPB > 100 km. We also performed a simulation of the long-term orbital evolution of the Trojan families. We used a modified version of the SWIFT symplectic integrator where the migration is set analytically. We found that the families are unstable even in the late stages of the migration, when Jupiter and Saturn recede from their mutual 1:2 resonance. Hence, the families observed today must have been created after the planetary migration ended. In the last part of the work, we study a formation of asteroid families in the Main Belt during the Late Heavy Bombardement. We simulate perturbations induced by migrating planets in the "jumping Jupiter" scenario (Morbidelli et al., 2010) and we conclude that big families (DPB > 200 km) created during the bombardement should be observable today.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / In this paper we analyze fundamental local-area communication issues related to proximity operations around near-earth asteroids. We are motivated by NASA's plan to send robotic spacecraft to numerous such asteroids in the coming years in preparation for an eventual manned mission. We consider here the case where multiple probes are deposited on the surface of an asteroid and must communicate the data they collect to each other and to earth by using the orbiting `mothership' as a relay. With respect to this scenario, we statistically analyze the ability of surface probes in various locations to communicate with the mothership as well as their abilities to network with one another. For the purposes of this analysis, we assume the simplest possible communications scenario: a surface probe can communicate with the mothership only when it has an unobstructed line of sight. At the frequencies of interest here, line of sight is a necessary condition but it is obviously not sufficient - the end-to-end link margins of our communications system must be high enough to support the desired/required data rates. The work presented in this paper extends our previous research in which we only analyzed the visibility of the locations on the surface of the asteroid. Here, we consider how visibility affects the required communications bandwidth and buffer sizes for both surface-to-spacecraft and surface-to-surface scenarios.

ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / In this paper we analyze fundamental local-area communication issues related to proximity operations around near-earth asteroids. We are motivated by NASA's plan to send robotic spacecraft to numerous such asteroids in the coming years in preparation for an eventual manned mission. We consider here the case where multiple probes are deposited on the surface of an asteroid and must communicate the data they collect to each other and to earth by using the orbiting `mothership' as a relay. With respect to this scenario, we statistically analyze the ability of surface probes in various locations to communicate with the mothership as well as their abilities to network with one another. For the purposes of this analysis, we assume the simplest possible communications scenario: a surface probe can communicate with the mothership only when it has an unobstructed line of sight. At the frequencies of interest here, line of sight is a necessary condition but it is obviously not sufficient - the end-to-end link margins of our communications system must be high enough to support the desired/required data rates. Nonetheless, this simplistic analysis represents the first step in characterizing the communication system requirement for the asteroid-local portion of the system.