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European Space Agency - developments & in-orbit experience SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 1 Outline Technology Development Cycle Technology Readiness Levels Instrument Development Cycle Missions in Operation XMM-Newton Integral Mars Express SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 2 Outline (continued) SDW2005 Missions in Development Herschel / Planck GAIA BepiColombo Future Missions Solar Orbiter Darwin XEUS Advanced Concepts & Science Payloads Office Science Directorate Page 3 Investment by Technology Domain Investment per Technology Domain • Increasingly complex science instrumentation requires corresponding investment in Automation & Others AOCS & GNC TT&C Robotics 3% 11% Thermalinfrastructure 10% spacecraft 4% 4% & • Structure For example pointing stability, on-board data Mechanism Data Handling processing must improve 4% 5% • Nevertheless the instrument funding by ESA Propulsion remains the most critical Detectors 6% 16% Power 5% Optics 32% SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 4 ESA Science Programme • Missions are based on existing technologies, or technologies which might require some modest evolutions or modifications (relatively high TRL level) • New and more efficient, or ever more demanding Science Missions have to rely on innovative and novel technologies, on the spacecraft and also particularly the payload side (Optics and Sensors). • An innovative technology program is therefore the required base for any creative and productive long-term science programme. • But currently the funding base is being eroded ………. SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 5 How are technologies selected? • Astronomy: typically <1 mission / decade per wavelength domain, • Planetary science missions to different destinations, with remote and in situ follow-ups implies < 1/decade/planet • Solar observatories are weakly motivated to exploit the 11yr natural cycle for the next generation instruments • Next mission is always beyond current science programme lifecycle. [Current programme is fixed to 2014] • Frequently a mission’s science goals evolve [priorities and themes change with other science discoveries including those of other agencies] • Can forecast only generic technology challenges for any major enhancement of capability (~order magnitude improvement performance) or the introduction of a new techniques (image/spectroscopy/polarimetry/timing/particle species etc.) SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 6 The life-cycle of a Science Instrument ESA Novel Technology R&D Phase 2: Improvements, Demonstrators Science Institutes Instrument National Funding Pre-development Breadboards, Qualification of Technology New instruments SDW2005 AO Detailed Instrument Design, Consortia Instrument Proposals Instrument Integration Onto Spacecraft, Launch, Operation Science Selection Novel Technology R&D Phase 1: New ideas, Fishing Instrument Building, Qualification, Calibration Instrument Implementation Advanced Concepts & Science Payloads Office Science Directorate Page 7 The Catch 22 SDW2005 Innovative Science Missions Novel Technologies Require Novel Technologies: Non-existant Require Prospective Science Mission for Justification Premature for Science Programme Not relevant for Missions in B/C/D Rejected Rejected Advanced Concepts & Science Payloads Office Science Directorate Page 8 Technology Readiness Levels and ESA Funding Programmes TRL 1-3 TRL 4-10 TRP CTP-A CTP-B GSTP Creative, innovative Technologies Pre/Assessment Phase SDW2005 Existing, proven Technologies Definition Phase Advanced Concepts & Science Payloads Office Science Directorate Page 9 Despite the best laid plans….. • Qualification for vibration, thermal environment and radiation may limit preferred design options • Inevitably resourcing of flight instruments through PI-led consortia can be hostage to delays • Testing and calibration time come under severe time pressure • The cost of running the spacecraft contract is huge – therefore pressure to launch on-time prevents the full testing of instrument • We examine here some cases of operational “surprises” SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 10 XMM SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 11 XMM Lessons learned concern the in-orbit environment • Pre-launch concerns about environment (eccentric 100,000 km) Moveable shutter for belt passage protons (cf. CHANDRA) • Contamination to be mitigated with out-gassing chimney/cold-trap. • Soft protons flares ~ 20% of operation (soft 10’s keV) • Micrometeorites – 1/yr/camera, they scatter at grazing incidence off mirrors. Local damage and worse ….. • Enhanced charged particle background - GEANT 4 modeling? • User interaction – flat field set up 100’s –1000’s seconds • CCD electronics infant mortality SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 12 Integral • Ge detectors – cryogenic spectrometer at 80K. Radiation damage factor 2 worse than expected, Requires annealing every 6 months – a loss of observing time (and suspected loss of diodes through thermal cycling?) • Background also twice expected, spectral lines and showers reduce sensitivity • JEM-X – contamination in glass strips – breakdown in gas exacerbated by high backgound rates, gain had to be reduced (poor calibration) SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 13 Mars Express • High Resolution Stereo Camera • 9 CCD lines of 5100 pixels, 32kg • The ultimate resolution of 2m at orbit height 250km has not been achieved • Complex optics train, requires exceptional thermal stability and control • Suggests more comprehensive testing and calibration should be considered SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 14 Herschel • Discovering the earliest epoch of proto-galaxies, cosmologically evolving AGN-starburst symbiosis, and mechanisms involved in the formation of stars and planetary system bodies. • 3.5 metre diameter passively cooled telescope 60 - 670μm. • The science payload complement two cameras/medium resolution spectrometers (PACS and SPIRE) and a very high resolution heterodyne spectrometer (HIFI) will be housed in a superfluid helium cryostat. • Herschel will be placed in a transfer trajectory L2, 2007 3 yrs SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 15 PACS • Photoconductor Array Camera & spectrometer • 3 Ge:Ga photoconductor linear arrays for spectroscopy & 2 Si bolometers • 50 passive & active optical elements 4 precision mechanisms • 3 photometric bands with R~2. • `blue' array covers the 60-90 and 90-130 µm bands, while the `red' array covers the 130-210 µm band. • Field of view of 1.75x3.5 arcmin • An internal 3He sorption cooler will provide the 300 mK environment needed by the bolometers. • Spectroscopy covers 57-210 µm in three contiguous bands, with velocity resolution in the range 150-200 km/s • The two Ge:Ga arrays are stressed and operated at slightly different temperatures SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 16 PACS Array design SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 17 SPIRE 3-band imaging photometer (simultaneous observation in 3 bands) • Wavelengths (μm): 250, 350, 500 • Beam FWHM (arcsec.): 71, 24, 35 • Field of view (arcmin.): 4 x 8 • 3He cooler Imaging Fourier Transform Spectrometer (FTS) • Wavelength Range (μm): 200-400 (req.) 200-670 (goal) • Simultaneous imaging observation of the whole spectral band • Field of view (arcmin): 2.0 (req.) 2.6 (goal) • Max. spectral resolution (cm-1): 0.4 (req.) 0.04 (goal) • Min. spectral resolution (cm-1): 2 (req.) 4 (goal) Spider web NTD Ge bolometer 0.3K hung from kevlar to 1.7K with 3He Sorption cooler SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 18 HIFI • Heterodyne Instrument for the Far-IR a spectrometer • 480 – 1250 GHz and 1410 – 1910 GHz • 134 kHz – 1 MHz frequency resolutions • 4 GHz IF bandwidth • 12 – 40" beam dual polarization sensitivity & redundancy • Superconductor/insulator/superconductor & hot electron bolometers • New technology for mixers and local oscillators etc.. SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 19 HERSCHEL • Combination of large He observatory cryostat and complex thermal interface with instrument coolers has been a huge programme risk • HERSCHEL also to launch with PLANCK – developments tied to another platform (to reduce launch cost $150M) • All instruments require substantial development and qualification (thermal design, vibration) • In future Agency may prefer to take on load of the cryo developments from PI – reduce risk but testing interface more complex? SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 20 Gaia Astrometry (V < 20): completeness to 20 mag (on-board detection) 109 stars accuracy: 10-20 arcsec at 15 mag (Hipparcos: 1 milliarcsec at 9 mag) scanning satellite, two viewing directions Radial velocity (V < 16-17): third component of space motion, perspective acceleration dynamics, population studies, binaries spectra: chemistry, rotation Photometry (V < 20): astrophysical diagnostics (5 broad + 11 medium-band) + chromaticity SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 21 GAIA Payload and Telescope Rotation axis SiC primary mirrors 1.4 0.5 m2 at 99.4° Superposition of fields of view SiC toroidal structure Combined focal plane (CCDs) Basic angle monitoring system SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 22 GAIA Astrometric Focal Plane Total field: - active area: 0.64 deg2 - number of CCD strips: 20+ 110+40 - CCDs: 4500 x 1966 pixels - pixel size = 10 x 30 µm2 Sky mapper: - detects all objects to 20 mag - rejects cosmic-ray events Astrometric field: - readout frequency: 55 kHz for AF2-10 - total detection noise: 5-6 efor AF2-10 Broad-band photometry: - 5 photometric filters Along-scan star motion in 10 s FoV2 FoV1 SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 23 GAIA On-board processing SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 24 GAIA – CTI concern • Mass limitation dictated rather thin exterior light shades – gave very large proton dose • Now measuring prototype CCD performance after 109 protons/cm2 • Smeared response would prevent centroids being accurately calculated • Performance depends upon history of stars within a column – need “thin zero “? SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 25 BepiColombo • Determination of mineralogy at spatial scale of large craters requires combination of visible, IR and X-ray imaging • Payload must sustain environment of solar irradiation, and cruise period of several years • X-ray instruments map high resolution fluoresence only at times of high solar flare fluence! • Optical and IR instruments require APS technology, room temperature operation, radiation hard • Uncooled broadband IR arrays – Si MEMS technology SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 26 BepiColombo instruments • Si MEMS technology to produce micro-bolometer • ¼ cavity for good response, produced with polymer lift-off technique • ~256x320 array mated to ASIC to allow pushbroom readout SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 27 BepiColombo instruments • GaAs room temperature spectrometer array • Mated to readout ASIC for 64 x 64 imager 200eV FWHM energy resolution at 1keV SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 28 Solar Orbiter • Observations at 0.2 AU – 25 Solar constants load • Active Pixel Sensors - CCD would suffer un-tolerable radiation damage at 0.2 AU and CMOS based APS are a key need for the mission (all Remote Sensing instruments). • Heat rejecting entrance window / EUV filters -The need to reject the heat before it reaches the S/C is a key requirement for the SolO instruments (foils and grids) • Fabry-Perot filters - select a narrow and tunable spectral band baseline is a double Fabry Perot followed by a band pass interference filter. The spectral tuning of both Fabry Perot is achieved by applying high voltage • Liquid Crystal polarisers- to select 4 independent input polarisation states using Liquid Crystal Variable Retarders • Solar-blind detectors – wide band gap needs development or use intensified CMOS APS SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 29 Darwin • 4 spacecraft at L2 orbit, 2m class telescopes • Nulling interferometry to reject primary star light by ~108 • Maintain baselines from 50m – 200m, with rotation - by formation flying • OPD established to 20nm within the beam combiner S/C • Require integrated optics & detectors for 4-20μm for spectroscopy SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 30 Darwin • Detectors could rely on JWST for 5-20μm • Eg linear array of BIB Si:As, but these need 8K temperature cf. optics 40K • Possible problem with vibrations from additional cooler SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 31 XEUS • X-ray astronomy observatory with 10m2 effective area via. novel silicon mirror plates modules • L2 orbit, MSC and DSC in formation flying 50 m apart • Imaging and spectroscopy requires new detectors developments SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 32 XEUS • Wide Field Imager – Si class energy resolution, and 100μm pixels • Huge mirror area means for photon counting that fast readout required • Use a DEPFET version of APS technology SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 33 XEUS • Cryogenic sensors to achieve non-dispersive spectroscopy λ /δλ ~ 1000 • STJ or TES readout of bolometers • Requires ADR coolers (50mK) and efficient light and IR-blocking filters, RF SQUID multiplexors SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 34 Summary Required Developments • Larger focal planes, with APS-like readout at all wavelengths • Europe lacks heritage in readout ASICs cf. HEP vertex detectors • Investment in novel optics and mechanical coolers will be as important (cryogen lifetime) • Early identification of technology, investment, early testing in appropriate environment • Common location for observatories is L2 – radiation damage and prompt effects are important (background/cosmic ray removal) SDW2005 Advanced Concepts & Science Payloads Office Science Directorate Page 35