ADASS XXI conference, , 6-10 November 2011 A new consortium : ESPaCE European Partnership for Computing Ephemerides

ROYAL OBSERVATORY OF BELGIUM

W. Thuillot1, V. Lainey1, V. Dehant2, J.-E Arlot1, J.-P. De Cuyper2, L.I. Gurvits3,7, H. Hussmann4, J. Oberst5, P. Rosenblatt1, J.-C. Marty6, B. Vermeersen7 and the ESPaCE team8

1IMCCE, ; 2Royal Observatory of Belgium; 3Joint Institute VLBI , Dwingeloo, The Nederlands; 4DLR Berlin, ; 5Tech. Univ. Berlin, Germany; 6Observatoire Midi-Pyrénées/CNES ; 7Delft University of Technology, The Nederlands; 8the complete ESPaCE Team: Arlot, J.-E. (IMCCE) , Bauer, S. (DLR), De Cuyper, J .-P. (ROB), Dehant, V. (ROB) , Dirkx, D. (TUD), Gurvits, L. (JIVE), Hestroffer D. (IMCCE), Hussmann, H. (DLR), Kudryashova, M. (ROB), Lainey, V. (IMCCE), Marty, J.-C. (CNES), Oberst, J. (TUB), Pasewaldt, A. (DLR), Rambaux, N. (IMCCE), Robert, V. (IMCCE), Rosenblatt, P. (ROB), Thuillot, W. (IMCCE), Vermeersen, B. (TUD), Vienne A. (IMCCE)

The European Satellite PArtnership for Computing Ephemerides (ESPaCE) is a new EC-FP7 program which aims at strengthening the collaborative activities in the domain of the development of ephemerides and reference systems for natural and .

The first purpose of the ESPaCE project is to explore and understand the IMCCE (Institut de Mécanique Céleste et de Calcul des Ephémérides, Paris Obs.). physical phenomena, the physical structure and the dynamical processes of the The main part of the activity is focused on the extraction and analysis of Earth’s Moon, the Martian moons and Deimos, as well as the numerous astrometric data from spacecraft measurements that have not yet applied moons of the Solar system, and of Jupiter and Saturn in particular, their origin, been used in the dynamic reconstruction and on the combination of their dynamics and their evolution. these data with ground-based astrometric data. The project will also advance the European expertise in ultra-precise tracking of planetary probes and The second purpose of this project is to link celestial mechanics, dynamics, other deep space science missions. By these means, we intend to provide new space science (Radio-science, LLR (Lunar Laser Ranging), VLBI (Very Long Baseline dynamical models for several natural satellites, a characterization of their Interferometry) and astrometry. rotation properties, and improve spacecraft orbit determination methods for The main output are the Martian, Jovian, Saturnian and Uranian satellites space science. ephemerides, as well as constraints on their interior and dissipation processes. st This 4 year project, which began on 2011 June 1 , is organized in 12 work- packages: co-ordination (management), Radio-science, laser ranging, VLBI (Very Long Baseline Interferometry), digitized data handling, astrometry, definition of coordination reference frames and improvement of planetary coordinate The ESPaCE project aims at strengthening the collaboration and at developing knowledge, methods for de-termination of spacecraft and satellites new knowledge, new technology, and products for the scientific community in ephemerides, formation of databases, data access and distribution methods, educational, outreach activities and scientific management. the domains of the development of ephemerides and reference systems for natural satellites and spacecraft by combining expertise of main European The project will concentrate at achieving maximum synergy between all the research centers involved in space sciences and dynamics, ROB (Royal work packages above in order to deliver to the professional communities and Observatory of Belgium), TUB (Technische Universität Berlin), JIVE (Joint Institute communities at-large the best scientific products adequate to the present-day for VLBI in Europe), TUD (Technische Universiteit Delft), CNES (Centre National cutting-edge space science and technology. d’Études Spatiales), DLR (Deutsches Zentrum Fuer Luft und Raumfahrt, EV) and

No WP Work to do Tasks list Deliveries list No WP Work to do Tasks list Deliveries list WP 1 Coordination WP 7 Coordinates and On the basis of space observations, the shape 1. Reference shape and gravity model for Phobos • Report on Phobos control WP 2 Radio-science Tracking data of probes which had flybys with 1. Collection of the Radio-science tracking data Reference and gravity model of the natural satellites can 2. Realization of the Phobos coordinate system point network, reference natural satellites will be collected and analyzed 2. A priori ephemerides systems be obtained. The WP7 will be devoted to 3. Realization of the Lunar coordinate system shape, and gravity model these tasks for the Martian satellites, the 4. Reference shapes of icy satellites • Report on Lunar coordinates thanks to a priori ephemerides of the objects. 3. Strategy development for the analysis WP2 MarsExpress Several considerations upon the acting forces, 4. Analysis of the tracking data Moon, and the icy satellites. A coordinate 5. Realization of icy satellites coordinate systems and selected base maps gravitational and non gravitational forces, will be system for these objects will be defined and a 6. Theory of rotation of the natural satellites • Report on icy satellites made in order to get the best results. These forces model of rotation could be deduced. These control point networks, will be estimated and precise orbit of the probes data will also be of use for physical shapes and coordinate will be computed. Other parameters such as mass ephemerides (precise aspect of the bodies systems versus the time) of the natural satellites. of the natural satellite will be determined. • Ephemerides biases • Spacecraft orbit SPICE kernels WP7 Phobos WP 3 Laser data Data from laser tracking will be analyzed and their 1. Information collection on laser tracking, VLBI and • Report on performance WP 8 Spacecraft and New dynamics models of the natural • Mars SPC, Galileo, Voyager 2 accuracy will be estimated. The data obtained Deep Space New. parameter. Of laser tracking, Satellite satellites and improved orbit models of orbit kernels during the LRO (Lunar Reconnaissance Orbiter) 2. Inventory of existing and required tools VLBI, DSN ephemerides spacecraft will be obtained by using the • Ephemerides of Martian, mapping mission will be analyzed. Software for 3. Selection and modification of preferred tools • Report on software packages digitalized astrometric data as well as Galilean and Uranian satellites solution of spacecraft trajectories will be 4. Performance studies for solutions of satellite spacecraft data. The dynamics models of the 1. Arc splitting method developed. 5. Demonstration project trajectories Martian satellites Phobos and Deimos will be 2. Merging data method • Report on selected software improved in particular on the basis of the 3. Modeling Mars SPC tool and on modification. and new analysis of the recent MEX data and the 4. Modeling Phobos/Deimos orbit fine-tuning for trajectory past Viking data. Combination between space 5. Mars global inversion determination observations and ground based ones, and 6. Modeling Galileo orbit • Report on performance study processing of data related to the satellites 7. Modeling Jovian satellite orbits incl. Quality estimation. Of and the probes, allow getting strong 8. Jupiter global inversion simulated and actual results constraints for the dynamics of the objects. 9. Modeling Voyager 2 orbit WP8 Phobos & Deimos • Report on LRO Laser Tracking Other data from the Galileo and Voyager 10. Modeling Uranian satellites orbit 11. Uranus global inversion WP3 Lunar Laser Ranging results missions will permit also to provide new ephemerides of the Galilean and the Uranian WP 4 VLBI Applications of VLBI technologies to spacecraft 1. Installation, verification and tests of the VLBI near- • Report and algorithms of ultra satellites and new orbital models of the tracking will be studied. VLBI tracking data will be field theoretical delay high spectral resolution SPC probes. Spice Kernels will be provided. analyzed in view of their use for various planetary 2. Verification and tests of the on-purpose developed signal correlation science objectives. A special software will be ultra-high spectral resolution correlate software for • Measured state vectors of the WP 9 Databases Setting up of databases and of the method to 1. Astrometric database • Collecting Topography data in developed and applied to SPC VLBI correlation SPC together with the a priori access the data and models developed in the 2. Rotation database standard format spacecraft VLBI observations. 3. Scheduling and performing test VLBI observation of state vectors used other WPs. 3. SPC Kernels • Collecting Satellite and SPC several existing SPC 4. Satellite kernels data in SPICE format 4. Post-correlation analysis of the broad-band far-field 5. Map images • Collecting Rotation data in phase referencing radio sources (from ICRF and 6. Topography standard format other catalogues) data and near-field narrow band • Selected image map and SPC data. topographic data products 5. Analysis of the results including documentation 6. Optimization of the observational, processing and WP 10 Data distribution Allowing the whole scientific community to 1. Astrometric database • Implementation of the WP4 EVN Radio Telescope, Yebes, Spain analysis techniques, recommendation. For further access our new data available. Databases will 2. Rotation database astrometric database development. be fed step by step, each time a new 3. SPC and satellite kernels • Implementation of the deliverable is available. 4. Map images SPC/Satellite kernels WP 5 Digitized data This WP is dedicated to the scan of many 1. Digitization of Mars plates • Digitized form of the plates of 5. Topography • Distribution of the planetary photographic plates of planetary systems of 2. Digitization of Saturn plates Mars 6. Planetary constants constants satellites. We have identified in particular plates of 3. Identification of new plates • Digitized form of the plates of 7. Interface with • Interface method with Martian, Jovian and Saturnian satellites to be 4. Digitization of relevant plates Saturn EUROPLANET IDIS EUROPLANET IDIS scanned. But we know that other relevant plates • Digitized form of the plates of can be available in archives of several new plates identified WP 11 Education and observatories; we shall find them and scan them. Outreach WP8 Ganymede, Io, Europa & Calisto This work is made possible thanks to the recent WP 12 Scientific setting up of a new digitizing machine in ORB. management

WP 6 Astrometry The data scanned in WP5 and other relevant data • Astrometric space data of will be analyzed in terms of astrometry in order Mars, Jupiter, and Saturn to obtain orbit model. Among these data, a special satellites work will be carried out for rare events, the • Mutual events data for the mutual events of the natural satellites (eclipses Uranian, Jovian and Saturn Phobos-Soil and occultations of satellites each other during WP5 Digitalizing Machine, ORB satellites the planetary equinoxes), which are the most 1. Reduction of Phobos/Deimos images • Astrometric data from and accurate astrometric observations from the 2. Reduction of mutual events data DAMIAN images ground. In this WP, a special task will be devoted 3. Reduction of Jovian images Phobos-Soil YingHuo-1 launch YingHuo1 to the astrometry of Phobos and Deimos which 4. Reduction of the Uranian images have been the goal of several space missions. 5. Reduction of the relevant images 8 November 2011 6. Reduction of the DAMIAN images

Acknowledgement of support from the EC's 7th Framework Programme (FP7/2008-2017) under grant agreement n. 263466.