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Jovian Minisat Explorer TRS. Overview of the Jovian Exploration Technology Reference Studies Current Status Jun-06. The Challenge of Jovian System Exploration. Peter Falkner & Alessandro Atzei Solar System Exploration Studies Section Science Payload and Advanced Concepts Office
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Jovian Minisat Explorer TRS Overview of the Jovian Exploration Technology Reference StudiesCurrent Status Jun-06 The Challenge of Jovian System Exploration Peter Falkner & Alessandro Atzei Solar System Exploration Studies Section Science Payload and Advanced Concepts Office ESA/ESTECPeter.Falkner@esa.int , tel: +31 071 565 5363
Overview of Jovian Technology Reference Studies • Current Status & News • Europa Explorer (Jovian Minisat Explorer) • Magnetospheric Explorer (Jovian System Explorer) • Atmospheric Entry Probe (Jupiter Entry Probe)
Jovian Minisat Explorer TRS Jupiter related Technology Reference Studies • Motivation: • providing minimal building blocks for future science missions • definition & development of enabling technologies for future science missions • enable realistic evaluation of proposals in the frame of ESA’s Cosmic Vision 1525 • several ‘theme proposals’ for Jovian System with in CV1525 exercise background • Presently the first phase of Jovian studies has been reopened • & a new phase has been initiated: 1.Jovian Minisat Explorer: Focussing on the exploration of Europa (or any other Galilean moon) 2. Jovian System Explorer: • Study of the Jovian magnetosphere (one or more magnetospheric S/C • Study of the Jovian atmosphere (one or more entry probes, up to 100 bar)
Jovian Minisat Explorer TRS Study Concept - Europa • Emphasis on a cost & resource minimised mission scenario: Done by small launcher, highly integrated payload & avionics, minisat • Configuration of phase 1: 1 Europa Orbiter (200km circular orbit) + 1 Jovian Relay Spacecraft (in orbit around Jupiter 12.7x26.3RJ) • 2 S/C approach rationale: • Lifetime, data rate and power limited:transmission of all data is impossible in the ~66 day JEO lifetime. a relay S/C is required capable of delivering all data to Earth • Europa radiation environment:stay outside radiation belts with equipment which is not needed for Europa exploration • Delta-V requirements:bring into Europa orbit only what is really needed there ! • Additional JRS science:JRS will be able to gather valuable scientific data on the Jovian system from its orbit during ~2 year in orbit lifetime • Additional Fly-by opportunities: • JRS: 1xCallisto & 5xGanymede GAM’s, JEO: 4xGanymedeGAM Highly Integrated P/L Suite
CRETE CDF for design verification & improvement JMO study 2003-2005 • Cases studies • all chemical • SEP transfer • Solar powered • RPS powered CDF JMO verification (Mar&Apr 06) Δv problem ~300m/s Some update on configuration mission profile unfeasible CDF Crete (May&Jun 06) Industrial JMO design & MA revisit Problem with additional radiation Feasible Mission 20% system + 4 % launchmargin
Major Modifications • Launch date 2019 into GTO and EVEEGA • JOI with Io gravity assist into initial orbit with 5 x 400 RJ • New target orbit JRS 11.2 x 28 Rj (resonant with Europa orbiter) (prev. 12.7 x 23.6 Rj) less distance for communication saves Δv JRS has 6 Ganymede GAM, JEO: 4xGanymede GAM • Smaller HGA 1.5 m 0.75 m • Structure change from Al to CFRP (FEM verification done) significant mass saving • 400 N 500 N engine (reduces gravity losses) • Europa Orbiter remains at 200 km circular polar orbit • Optimized launch vehicle adapter 70 40 kg • New radiation model (Salammbo) from ONERA under verification • Parametric analysis of JOI cases
Ballistic Transfer EVEEGA 2020 • VEEGA 2020 Worst Case in LW • Earth escape 2020/4/4 • Hyperbolic escape velocity: 3.17 km/s • Declination +43 deg • DSM: 32 m/s • Venus swingby: 2020/11/9 • Earth swingby 1: 2021/7/18 • Earth swingby 2: 2023/7/19 • Arrival: 2026/7/28 • Hyperbolic arrival velocity: 5.704 km/s • Transfer duration: 6.3 years
Ballistic Transfer: Added EGA • Launch in April 2019 (1 year earlier) with Soyuz-Fregat 2-1b • Departure velocity 3.17 km/s (as 2020) • Declination -22 deg • No DSM • Soyuz performance with 4 burn escape strategy • Around 1960 kg with 4 burn strategy into escape • Starting out from GTO-like inclined orbit (s/c mass ca. 3090 kg incl. adapter) • Ariane 5 ECA performance: 4855 kg including adapter
Option: Ballistic VEEGA 2021 and 2023 • VEEGA 2023 • Earth escape 2023/6/4 • Hyperbolic escape velocity: 3.31 km/s • Declination -21 deg • DSM: 20 m/s • Arrival: 2030/2/91 • Hyperbolic arrival velocity: 5.59 km/s • Transfer duration: 6.6 years • VEEGA 2021 • Earth escape 2021/11/27 • Hyperbolic escape velocity: 3.79 km/s • Declination +12 deg • DSM: 5 m/s • Arrival: 2028/7/9 • Hyperbolic arrival velocity: 5.57 km/s • Transfer duration: 6.6 years Needs further analysis and optimisation Waiting documentation of current studies
Sensitivity Analysis (Option 1/chemical) Extra solar arrays mass needed for 10 W of extra power during operational phase 3.50 kg • Launcher performance (w.o. adapter) 3050.0 kg • Composite wet mass 2925.0 kg • Launcher margin 125.0 kg • Max extra payload allowed36.0 kg
Launcher performance 2230.0 kg Composite wet mass 2185.5 kg Launcher margin 47.5 kg Max extra payload allowed21.5 kg Sensitivity Analysis (Option 2/SEP)
Radiation model coverage Spatial coverage D&G out 83 D&G in 83 GIRE Electron Salammbô L 6 8 9.5 12 16 Salammbô Proton D&G 83
Background Energy coverage D&G in and out 83 GIRE Electron Salammbô MeV Proton Salammbô D&G 83
Design for Option 1/chemical • Same as REIS option 1 (except of HGA of JEO) • JRS • box structure • main driver: 4x EUROSTAR 2000+ dimension • JEO • Box structure • Main driver: tank sizes, instruments volume and field of view • LVA • A dedicated truss structure adapter that interfacing 8 point of FREGAT and 4 point of the box structure S/C
S/C Configuration (2): transfer configuration - 230 W required for JEO, 300 W required for JRS (EOL) - JEO & JRS at 5 AU, solar array size~15 m2 (each) (GaAs + concentrators) - Rosetta at 5 AU, solar array size 2*32 m2 (Si) - Juno is baselining the use of Rosetta solar cell technology
S/C Configuration (3): Relay Satellite propulsion system 10N thrusters (x16) Eurostar 2000+ tank (x4) Helium tank (x2) 500N main engine
S/C Configuration (3): JEO operational configuration Ground penetrating radar Nadir pointingside for GPR Changed JEO Nadir pointing sidefor optical instruments Magnetometer
Highly Integrated P/L Suite – Design Study and Bread Boarding Highly Integrated Strawman Payload used in the study Highly integrated P/L and Avionics required for radiation protection Payload resources based on dedicated studies and derivatives of BC HIPS payload Total: 16 kg, 10 W + use of launch margin for P/L and or add. shielding Total: 34 kg, 33 W
Main challenges for JME • Surviving deep space as well as Jupiter’s extreme radiation environment: • Radiation hardened components (~1 Mrad) + radiation shielding or additional shielding mass (+20 kg) to relax the requirements needs trade-off • Radiation optimised solar cells, LILT GaAs development required • RPS systems, should solar cells be unfeasible: development/procurement/implications • Thermal variations (Venus hot case, Jupiter cold case) • Development of highly integrated systems (incl. low resource P/L) • Low power deep space comms (now at fixed data rate) • Highly autonomous mission capability • Planetary protection compatible systems • Balance between low cost and investments in new developments • The technology development activities that are identified in these studies will have to be started soon should similar mission concepts be selected for the CV 1525
Conclusions - JMO • Mission remains challengingalthough CDF gives 20% Sys. + 5 % Launch margin • Reduction of Radiation Hardening for components by use of additional shielding can be used = reduces development challenges and cost • Highly integrated P/L (HIPS) and Avionics (HIAS) is required to allow for effective shielding with additional mass • New: IO fly-by for Jupiter insertion • Launch date 2019 with EVEEGA transfer. • Further launch dates need confirmation • Mission Executive Summary will be updated to reflect the most recent findings -> ESA web.
Current activities • Studying additional Jovian study scenario’s in view of CV 2015-25 recommendations, e.g.: • Jovian Magnetospheric S/C • Magnetopause • Magnetotail • Poles (aurorae) • Jupiter Atmospheric Probes • Up to 100 bar • Assess minimum configuration for relevant science • Assess feasibility of combining atmospheric probe with magnetospheric mission (EMC, stabilisation, etc.)
View perpendicular to equatorial plane View in equatorial plane View perpendicular to equatorial plane View in equatorial plane View perpendicular to equatorial plane View in equatorial plane Considered magnetospheric mission scenarios Single S/C, equatorial plane: Magnetotail 15x200 Rj Dual S/C, equatorial plane: Magnetopause + Magnetotail 70x15 Rj 15x200 Rj Dual S/C, equatorial and polar plane: Magnetopause + Magnetotail + Poles 70x15 Rj 15x200 Rj
Entry Probe • 40 bar probe: • Mass ~ 270 kg • P/L resource ~ 12 kg, ~30 W (peak), ~350 bps • Entry latitude between -7 and +3 deg • Two probes + one orbiter • Descent time = 1 hour • Comms scenario complicated but should be feasible • 100 bar probe: • Mass > 320 kg • P/L resource ~ 12 kg, ~30 W (peak), ~350 bps • Entry latitude +3 deg • One probe + one orbiter • Descent time = 1 hour • Variable power comms system to cope with very strong atmospheric attenuation (~23 dB) All dimensions in mm
Swingby-Augmented JOI Outbound arc (elliptic) Inbound arc (hyperbolic) Ganymede swingby (perijove – 16 h) perijove 2nd JOI opportunity “after relay” 1st JOI opportunity “before relay” Relay phase Here: Example with Ganymede swing-by
Accommodation Back cover 3 layers: ablator, structure, IFI Pilot chute Antenna’s Main chute available volume Upper Shell Platform Lower Shell Front shield 3 layers: ablator, structure, IFI
Thank You Any Questions ?