Planetary Defense Ground Zero: MASCOT's View on the Rocks - an Update between First Images and Sample Return

At 01:57:20 UTC on October 3rd, 2018, after 3½ years of cruise aboard the JAXA spacecraft HAYABUSA2 and about 3 months in the vicinity of its target, the MASCOT lander was separated successfully by from an altitude of 41 m. After a free-fall of only ~5m51s MASCOT made first contact with C-type near-Earth and potentially hazardous asteroid (162173) Ryugu, by hitting a big boulder. MASCOT then bounced for ~11m3s, in the process already gathering valuable information on mechanical properties of the surface before it came to rest. It was able to perform science measurements at 3 different locations on the surface of Ryugu and took many images of its spectacular pitch-black landscape. MASCOT’s payload suite was designed to investigate the fine-scale structure, multispectral reflectance, thermal characteristics and magnetic properties of the surface. Somewhat unexpectedly, MASCOT encountered very rugged terrain littered with large surface boulders. Observing in-situ, it confirmed the absence of fine particles and dust as already implied by the remote sensing instruments aboard the HAYABUSA2 spacecraft. After some 17h of operations, MASCOT‘s mission ended with the last communication contact as it followed Ryugu’s rotation beyond the horizon as seen from HAYABUSA2. Soon after, its primary battery was depleted. We present a broad overview of the recent scientific results of the MASCOT mission from separation through descent, landing and in-situ investigations on Ryugu until the end of its operation and relate them to the needs of planetary defense interactions with asteroids. We also recall the agile, responsive and sometimes serendipitous creation of MASCOT, the two-year rush of building and delivering it to JAXA’s HAYABUSA2 spacecraft in time for launch, and the four years of in-flight operations and on-ground testing to make the most of the brief on-surface mission

Mascot: Analyses of the Descent and Bouncing Trajectories to Support the Landing Site Selection

The Japanese mission Hayabusa-2 has been launched in December 2014 towards the near Earth asteroid 1999JU3, also called Ryugu. This carbonaceous asteroid considered to conceal unchanged traces of the Solar System’s origin will be reached by the JAXA space probe in 2018. As done by its predecessor for the asteroid Itokawa a few years ago, Hayabusa-2 will observe Ryugu during several months and perform a touchdown to gather samples before returning them to Earth. In addition to the three Japanese micro-landers MINERVA taken on board, the probe carries the German-French lander Mascot (Mobile Asteroid Surface Scout). This shoe-box sized spacecraft of 10 kg is equipped with four scientific instruments aiming at improving the knowledge of mineralogical, geological, magnetic and thermal characteristics of Ryugu. It has no propulsive system and is planned to land onto Ryugu’s surface by the end of 2018 after a passive descent from an altitude of a few tenths of meters

La innovation en el mundo rural : en busca del buen vivir desde la action colectiva

Texto de la intervención está disponible aquí: http://www.ciea.com.ar/web/CIEA2019/CIEA2019.htmInternational audienceIntroducciónEl trabajo que se presenta forma parte de un proyecto de investigación bi-nacional más amplio, que se apoya sobre una hipótesis central: las ciudades intermedias – en interacción con los espacios rurales y agropecuarios – tienen un papel articulador en la dinámica de las recomposiciones territoriales de los dos países que estudiamos: Francia y Argentina. El objetivo es demostrar que existen ciudades intermedias en el espacio rural, que tienen un rol esencial de articulación, competencia y complementariedad funcional en los territorios. Estas ciudades presentan perfiles variados en contextos socio-económicos diferentes, aun cuando todas son centros ligados al mundo rural y a la actividad agropecuaria de manera específica.Las ciudades en estudio en Argentina están en la región Pampeana y son identificadas por su rol funcional para el sector agropecuario y para los espacios rurales circundantes, por su posición en la jerarquía urbana y por un hinterland agrícola extendido. Dentro de los aspectos en común que hemos identificado, aparece la búsqueda del “buen vivir” de personas que encontraron en el mundo rural una forma, no solo de resolver su subsistencia, sino de construir nuevos territorios. Así, a partir del concepto de innovación social y acción colectiva nos proponemos debatir cómo en el territorio pampeano, pueblos rurales del Partido de Tandil - Fulton, Vela y Gardey - a través de emprendimientos individuales han permitido una acción colectiva que tiene como propósito (invisibilizado) la búsqueda de la felicidad.Marc Augé plantea que en los estereotipos más difundidos, el lugar es presentado como la forma acabada de la felicidad y la realización personal, y que si el lugar se define como un espacio en el que es posible descifrar las relaciones sociales, los símbolos que unen a los individuos y la historia que les es común, no se deduce de ello que es ‘por definición’ un espacio de felicidad. Este trabajo propone demostrar que existen territorios en donde la innovación social es la que ha permitido organizar nuevos lugares. Desde esta perspectiva es que nos planteamos, ¿Aparece una nueva tendencia vinculada al mundo rural y a la felicidad o buen vivir de los individuos?Dar visibilidad a estas experiencias y considerarlas como “innovaciones sociales discretas” (Albaladejo, 2017), procura contribuir con elementos concretos, para que los agentes de desarrollo tengan instrumentos para orientar las políticas públicas en el territorio, dado que el estado en todas sus dimensiones debería cumplir un rol fundamental a partir de implementar políticas públicas específicas.El artículo lo hemos estructurado en tres apartados. En primer lugar, abordaremos una visión teórica alrededor del concepto del “buen vivir” y de “innovación social”, para en un segundo apartado dar respuestas empíricas a esos conceptos a partir del análisis de los casos situados, en los pueblos rurales del Partido de Tandil. Para culminar, a modo de reflexiones finales, nuestro aporte propone colocar en el debate, una tendencia incipiente que permite identificar una nueva dimensión de la articulación rural-urbana

TRAJECTORY DESIGN AND OPERATIONAL CHALLENGES FOR THE EXPLORATION OF PHOBOS

Designing trajectories to allow for long observation campaigns of planetary moons is not an easy task. Quasi-Satellite Orbits are a type of distant retrograde orbits suitable for Phobos exploration missions, as they offer a convenient means to orbit this moon in the sense of relative motion. MMX (Martian Moons eXploration mission) is a chemical-propulsion sample return mission currently under development at the Japanese exploration agency (JAXA) which plans to make extensive use of QSO (Quasi Satellite Orbits) trajectories during its threeyear stay in the vicinity of Phobos. Moreover, the French Space Agency (CNES) contributes to the mission analysis studies of MMX for the Phobos proximity phase in the frame of a larger collaboration between the Japanese and the French agencies, which also includes the delivery of a major payload (MIRS), as well as a rover built in collaboration with the German agency (DLR). Several of the major challenges that MMX teams have to face when building orbital scenarios exhibiting the best trade-off in terms of scientific return, maneuver cost and operational risk will be outlined in this paper. In particular, this work focuses on the contribution of the flight dynamics team at CNES to the design of three dimensional QSO trajectories and their operational use. An overview of the methods implemented to support the choice of suitable spatial trajectories around Phobos, in addition to the design of transfer trajectories, station-keeping and eclipse analyses for 3D-QSO will be presented.AAS 20-53

MASCOT aboard Hayabusa2: Status of Landing Preparations

MASCOT (’Mobile Asteroid Surface Scout’) is a 10 kg mobile surface science package on-board JAXA’s Hayabusa2 spacecraft, which, by July 2018, will have reached the near-Earth Asteroid (162173) Ryugu. MASCOT has been developed by the German Aerospace Center (DLR) in cooperation with the Centre National d’Etudes Spaciales (CNES). The concept of MASCOT is to perform in-situ measurements on the asteroid’s surface and to support the Hayabusa2 mission in the sampling site selection. MASCOT is equipped with 4 scientific instruments: a wide angle camera, an IR spectrometer, a radiometer, and a magnetometer. The data provided by the instruments aboard the Hayabusa2 spacecraft from June till September 2018 will be used to select both, sampling sites for the main spacecraft but also the best landing site for MASCOT. Besides of scientific preferences, the main selection criteria will be illumination (thermal), flight dynamics, visibility from main spacecraft and minimum interference between sampling and landing sites. The landing of MASCOT is scheduled for October 1, 2018. The paper will give an update of the status of MASCOT operations planning and landing site selection, 3 months before the actual landing

DROID: A mission concept to accompany and characterize Apophis through its 2029 Earth closest approach

International audienc

The MASCOT Separation Mechanism - A Reliable, Low-Mass Deployment System for Nano-Spacecraft

The Mobile Asteroid Surface Scout (MASCOT), an Asteroid Lander carried by the Hayabusa2 spacecraft, successfully landed on the Near-Earth Asteroid (162173) Ryugu on October 03, 2018. Hereby accomplishing the first ever landing of a European spacecraft on the surface of this type of celestial body. MASCOT was a prototype design of a new class of nano-size surface science packages for the exploration of small solar system bodies. The very low gravity (thus, very low escape velocity) of the target body required the design of a miniaturized deployment mechanism with a relatively small, well reproducible separation velocity. In addition, the mechanism also had to safely restrain the lander to the mother spacecraft during the launch and its 3.5 years cruise phase. In this paper, we describe in detail the design, numerical analysis and test of this newly developed separation mechanism. Furthermore, we compare the mechanism to other existing deployment systems and verify its performance with two independent analysis methods using actual flight data taken during the ultimate flight activation event, which initiated the successful delivery and surface operation of the MASCOT asteroid lande

The process for the selection of MASCOT landing site on Ryugu: design, execution and results

International audienceMASCOT, the Mobile Asteroid Surface SCOuT, is a small lander jointly developed by the German and French space agencies [Ho et al., 2017], that travelled on board of the JAXA Hayabusa2 spacecraft for over 3 years to the C-type asteroid Ryugu. The goal of MASCOT was to perform in situ measurements on the surface of the asteroid by means of its four scientific instruments, substantially contributing in this way to the overall scientific return of Hayabusa2 mission. The objective of the paper is to provide a detailed overview of the Landing Site Selection Process (LSSP) for MASCOT, from the preliminary design phase that started several years before launch, up to the actual execution of the selection process and its operational implementation. The effort that was put on the LSSP by all the teams involved over all these years was one of the key elements, leading to the unprecedented success of this mission

Quick-look results for the surface/regolith mechanical properties of Ryugu based on MASCOT bouncing analyses

We present quick-look results and constraints on the mechanical properties of the regolith on asteroid 162173 Ryugu, based on expected data regarding the mechanical interactions by the lander MASCOT as well as data from MINERVA nano-landers and possibly from the first sampling touchdown by Hayabusa2. MASCOT is going to be deployed from an altitude of ~55 m and has a touch-down velocity of ~0.2 m/s. It is expected to bounce several times before coming to rest [3]. The descent trajectory and the larger bouncing arcs can be captured by optical imaging from the spacecraft (ONC [5]) giving constraints on MASCOT in-flight trajectories. Moreover, direct images of footprints as well as data from MASCOT’s magnetometer MASMAG [4] on bounce times (and possibly rotation rates or changes thereof), images by MASCOT’s camera MASCAM [2] during bouncing and their fusion with ONC images projected to the shape, and finally MASCAM images after rest offer a rich database that allows us to constrain Ryugu’s surface mechanical properties, with implications on the asteroid’s surface history. Variations of the radio-frequency signal all along MASCOT’s trajectory and day/night detection by MASCOT’s photoelectric cell sensors can also contribute to the analysis. The measured total linear energetic coefficient of restitution (CoR), i.e. the fraction of energy dissipated at each bounce, can be compared to the CoR values measured for the MASCOT structure bouncing against a hard wall [6] and soft-sphere DEM simulations of MASCOT landing on a bed of granular material [7,8]. Footprint images of the bounce imprints in loose granular material also constrain the granular frictional properties and the regolith depth. Preliminary conclusions on the mechanical properties of Ryugu’s surface material will be draw