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This overview provides an introduction to the Simbol-X study program and its activities, including the spacecraft system architecture, scientific requirements, and formation flying technology. It also outlines the industrial organization and tasks involved in the pre-phase study.
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Pre-Phase A SIMBOL-X Study Program and activities overview
Pre-Phase A SIMBOL-X StudySimbol-X top-level scientific requirements *Secondary objective to be fullfilled if resources allow.
Spacecrafts System ArchitectureFunction sharing along DSC and MSC • Scientific requirements implies x-ray Woltier 1 optics with focal length of 20 meters: consequently the mission is possible by the means of two satellites named MSC and DSC • The Mirror Spacecraft (MSC) carries the 600mm diameter X-Ray Mirror. • The Detector Spacecraft (DSC), (lighter w.r.t. MSC) , is maintaining actively an accurate formation flying (position and orientation) with respect to the MSC • The MSC is in charge of controlling its attitude using Reaction Wheels, themselves unloaded by the chemical propulsion. • The DSC is tracking the MSC using high accuracy cold gas propulsion for translation control and Reaction Wheel (unloaded by the cold gas propulsion) for attitude.
Formation Flying technology The Simbol-X challenge • The Simbol-X mission is a perfect illustration of Formation Flying Concept, were distribution of the different functions of the payload over two spacecrafts allows to increase considerably the optical focal length of the X-ray telescope. • The achievement of a formation flying mission implies the development of specific technologies.
Mirror Module Thermal Baffle Sky Screen Mirror Module Sun Shield Mirror Spacecraft Design FeaturesAAS assessment before Pre-phase A MSC concept is based on combined heritage from PRIMA/SAX subsystems N2H4 Tank S-band Antenna Battery Reaction Wheels Thrust Cone Thrusters Launch vehicle adapter ring Mirror Module Adapter Mirror Module
Mirror Spacecraft Design FeaturesAAS assessment before Pre-phase A
Payload I/F Battery GN2 Tank RFS Antenna Detection Electronics Sun Shield OCXO Gyros Collimator CLS Reflector RF Terminal Reaction Wheels Telescope Electronic X-ray Detector FF Telescopes PCDU SMU Star- Trackers Communication Panel (S-Band) Optical Bench Detector Spacecraft Design FeaturesAAS assessment before Pre-phase A DSC concept is based on combined heritage from Proteus & Spacebus4000 subsystems
Detector Spacecraft Design FeaturesAAS assessment before Pre-phase A
Mission performances & budgetsAAS assessment before Pre-phase A • Launcher: Soyuz-Fregat / Kourou • Launcher capability • ~ 2300 kg of injected mass • ~ 300/253000 km • Final orbit • CNES Reference: • Apogee/Perigee: 253000/40000 km • Period: 7 days • Contact with G/S: 12-28 h • Final orbit injection througth the satellite propulsion thrusters
Pre-Phase A SIMBOL-X StudyStudy Objectives On Septeber 6 th Simbol-X Pre-phase A study (Customer ASI) startThe following topics are the references for the pre-Phase A study: • Preliminary MSC system configuation • Thermo-structural analysis and simulation of the Mirror Module • Feasibility study for the development, integration and test of the Mirror Module • Study of the Malindi ground control centre utilization • Scientific support activities for the consolidation of the scientific goals and requirements • Study of possible Italian contribution to the focal plane instrumentation • Study of satellite separation after injection
Pre-Phase A SIMBOL-X StudyIndustrial Organization • Alcatel Alenia Space Italia is the Prime Contractor • for Simbol-X Pre-Phase A study. The following • tasks are under its direct responsibility: • Preliminary MSC configuration, considering: • - Mirror Module accommodation • best utilization of national platform • Interfaces on launcher and DSC • - stacked launch configuration with DSC • - preliminary MSC budgets • MM Thermal-Structural I/F preliminary analysis • Mission Analysis considering • - available Simbol-X mission references • - evaluation of the orbital parameters • - Malindi Ground Center utilization • Identification of focal plane national contribution BCV progetti S.r.L. is in charge to perform preliminary thermal/structural analysis of the Mirror Module design on the basis of I/F data from AAS-I. Media Lario Technologies is in charge to define the production organization necessary to respect the Simbol-X necessity in terms of performances, quality and schedule (reference Simbol-X launch within 2013).
Pre-Phase A SIMBOL-X StudyINAF TASKs The INAF sub-contractor activities are organised in the frame of a team of INAF institutes, named SST (Simbol-X Scientific Team) under the coordination of OAB. INAF is in charge to support AAS-I for the following tasks: • MSC configuration topics correlated with the scientific mission and for the identification of contribution on focal plane; • Identification of Scientific requirements to be considered for the mission and the satellites; • Evaluation of the expected background level and components; • Implementation of the multilayer X-ray optics at the level of characteristics, development, production and accommodation on Mirror Spacecraft (MSC); • Analyses the stray-light in the band of telescope sensitivity (Visible, U.V., X-Ray), in particular defining: • Intrinsic MM stray-light; • MM Pre-collimator characteristics to limit stray-light; • Blanket (light filter) on MM (evaluating the available products)
Pre-Phase A SIMBOL-X StudyStudy Logic SIMBOL-X Pre-Phase A Study Activity flow and logic Definition phase Progress Meeting Consolidation phase
Activities Schedule Definition Phase ConsolidationPhase Here we are
Pre-Phase A SIMBOL-X StudyDefinition Phase • Scientific reqts. • Orbit evaluation • Preliminary MSC config. • MSC/DSC functions sharing analysis • Background vs. Orbit evaluation • Straylight sharing along MSC/DSC • Malindi station utilization • Proposed focal plane contribution
Pre-Phase A SIMBOL-X StudyConsolidation Phase • Scientific reqts.consolidation • Preliminary analysis of thermostructural loads on MM • Consolidation of MM design • Consolidation of background evaluation vs. Orbit • Implementation of safety measures against straylight • Budgets consolidation (mass, power, tlm) • MSC configuration consolidation • Consolidation of contribution for the focal plane • MM production planning • Any other aspects to be considered for the Phase A study
Pre-Phase A SIMBOL-X StudyMeeting Status • Past events: • K.O. 06/09/2006 at ASI (Roma) • Technical Meeting on MM 13/09/2006 at BCV (Milano) • Progress Meeting 1 with SubCo 05/09/2006 at AAS-I (Torino) • Next events: • Progress Meeting 2 with ASI 26/11/2006 at ASI (Roma) • Progress Meeting 3 with SubCo 06/12/2006 at AAS-I (Torino) • Final Meeting 05/01/2006 at ASI (Rome)
Pre-Phase A SIMBOL-X StudyPreliminary MSC system configuation • MSC Building blocks By the means a first analisys input to MM have been estrapolated
Pre-Phase A SIMBOL-X StudyPreliminary MSC system configuation • This table reports the indentified • Sub-System functions and the • possible choice. • Shopping list shall privilege: • Standard/recurrent products; • Use of technology well known;
Pre-Phase A SIMBOL-X StudyThe Mirror Module • Mirror Module first reference have to be consolidated in terms of: • Mirror shell characteristics (thickness, material...); • Mass; • Mechanical stress and temperature; • Inteface versus spacecraft (adapter); • Preliminary mirror module concept have • to be completed by the means of: • Implementation of precollimator (if any); • Implementation of particles deflectror; • Implementation of thermal filters;
Pre-Phase A SIMBOL-X StudyMirror Module Preliminary Design Credits BCV
Pre-Phase A SIMBOL-X StudyMirror Module First structural analysis The pictures reports the first four modes of the structure A MM mass of 450 kg (extrapolated for an HEW ≤20”) has been considered Credits BCV
Pre-Phase A SIMBOL-X StudyMirror Module First thermal-structural analysis Ray-tracking picture is refered to a thermal variation of 1°C between MS case/spiders on the Mirror Shell 1 Credits BCV
Pre-Phase A SIMBOL-X StudyMirror Module Preliminary Thermal Design Each of the 100 MS is reppresented by 4x4 nodes X-ray filter is supposed on top/bottom with settable thermal parameters
FRONT GRID SPOKES OUTER RING BACK GRID INNER RING Pre-Phase A SIMBOL-X StudyX-ray filter/thermal screen possible implementation To ensure an optimised MM thermal control the implementation of a thin aluminum (about 1000Å) coating a plastic film is supposed. A similar solution was already implemented for UV/Ion or electron shields in the frame of Other X-ray missions, like XMM, Chandra, BeppoSAX (by AAS-I). INAF has simulated the X-ray transmission for several thickness of Aluminum (500-1500Å) on Polyammide substrated (2000 to 10000Å). A possible implementation of such a membrane on the mirror units is shown in figure. A grid sandwich (transparency of 98% already tested on BeppoSAX) is considered in order to increse the filter roubustness.
Pre-Phase A SIMBOL-X StudyMirror Module Additional Items A magnetic deflector is identified on Xeus for reduction of electron and protons flux reaching the X-ray detector. The deflection is obtained by means a magnetic field in the MSC that will be oriented tangentially to the mirror rays and it will be as thick as necessary to meet the required the minimum B L product of 1700 Gauss-cm. This magnetic field will be generated by means of permanent magnets installed on the rays. An example of magnetic deflector on Simbol-X based on Xeus/Xmm similar concept could imply the accommodation on the spiders of 24 permanent magnets (NdFeB7.6 g/cm2) Extimated Total mass: 17 kg
Pre-Phase A SIMBOL-X StudyMirror Module Production Study of the Mirror Module Production Organization (by Media Lario Tecnologies) The goal of the study is the Definition and the Consolidation of the Mirror Module production organization necessary to respect the Simbol-X requirements in terms of performances, quality and schedule. For the purpose the following tasks will be taken into account : MM need date & Time Schedule Telescope Design assumptions Master manufacturing and testing Mirror manufacturing and testing Mirror coating and testing Mirror unit integration and testing Model Philosophy The Outputof the study will be the Simbol-X Mirror Module ProductionPlan