cosine

6th Round Table on MNT Miniaturisation aspects for future payload technologies: limitations and possible trends

Stefan Kraft cosine Research B.V. Company information

ƒ cosine founded in 1998 as physics consultancy company ƒ 2 operating companies ¾ cosine Science & Computing B.V. ¾ cosine Research B.V. ƒ Research & development team ¾ 11 PhD physicists ¾ 5 physicists ¾ 1 computer engineer ¾ 3 support staff ƒ Located in Leiden, next to University, NL ¾ Clean room ¾ Laser and optics laboratory ¾ High energy radiation and electronics laboratory ¾ Powerful IT infrastructure established ƒ cR focussing on advanced instruments and measurement technologies for space

2 Outline ƒ Overview of solar system missions ¾ Review of history ¾ Overview past and coming launches ¾ S/C and P/L configurations ƒ Payload technology ¾ Typical payloads ¾ Miniaturisation potentials ¾ Potential resource reductions by miniaturisation ¾ Limitations ƒ Some examples ¾ Integrated payload architectures ¾ Photon counting laser altimeter ¾ Integrated designs and involved miniaturised components ¾Conclusion

3of 36 Spacecrafts in operation or planned – solar system

Cluster II

Venus Express

4of 36 Key data ESA solar system launch history ƒ Giotto, 1985, Ariane 1, 970kg, payload … ƒ Cluster II, 2000, Soyuz, 4x1.2t, 4x70kg ƒ Mars Express, 2003, 1.223 t, Soyuz, payload 116 kg ƒ SMART-I, 2003, 367kg, Ariane 5, payload 10kg ƒ ROSETTA, 2004, 3t, Ariane 5, payload ~150kg ƒ Venus Express, 2005, 1.27 t, Soyuz, payload 104 kg

ƒ BepiColombo, 2013, 2.3t, Soyuz, double launch, payload 60kg

ƒ Jupiter and beyond, S/C to P/L mass ratio even worse ƒ COSMIC VISION, 2 missions (small, medium), budget ~0.85MEuro – 17 member states – 1 planetary mission (likely) + ExoMars

5of 36 Most efficient launcher: Soyuz

ƒ Mass production ƒ One launch about every month ƒ 1725th launch last Wednesday from Baikonur ƒ Reliable, cheep (30 to 45MEuro), ƒ Good capacity (~7t into LEO), ƒ Low g ƒ Fairing external diameter: 4.11 m ƒ length: 11.4 m

6of 36 ROSETTA spacecraft

S/C, solar panels, Honeycomb 1.19m vertical 2.2 m high-gain antenna main platform thrust tube

7of 36 Venus Express

Covered Instruments, Al structure spacecraft thrusters 267 l propellant

8of 36 BepiColombo

ƒ Mercury Magneto- spheric Orbiter ƒ Sunshield ƒ Mercury Planetary Orbiter ƒ Mercury Transfer Module

9of 36 Missions to the outer solar system will most likely have a bad S/C to P/L mass ratio

Supported by observations from previous missions

Miniaturisation and advanced technologies are particularly challenging and stimulate industrial innovations / spin-off

Rewarding and exciting profession / attractive to young engineers and technicians

10 of 36 Objectives

ƒ Improve – Number of scientific instruments or scientific return – Performance – Turnover time ƒ Save – Mass – Power – Size – Cost How?

11 of 36 Miniaturisation and integration

ƒ Making instruments smaller? – Yes, but does not work always – Need to collect enough photons from planets ƒ What helps is: – To use ¾ single aperture for larger spectral ranges ¾ more sensitive detectors ¾ lighter structures ¾ common supply units ¾ less wires ¾ instrument synergies ¾ advanced concepts (old and new)

12 of 36 Typical planetary instrumentation

ƒ Remote sensing – Gamma-ray spectrometer – X-ray spectrometer – UV spectrometer – Imager / camera / stereo – NIR and MIR spectrometer ¾ Mineralogy (medium resolution, broad band) ¾ Atmosphere research (high resolution, dedicated bands) – Radiometer ¾ Temperature ¾ Thermal inertia ¾ Dynamic flow processes – Microwave sounder / radar ƒ Exotic instruments (body investigation) ¾ Accelerometer / gradiometer ¾ Laser altimeter

13 of 36 Identified resource reductions

Some examples

14 of 36 Gamma-ray spectroscopy

ƒ Room temperature operation – Use of scintillators – Adapted for BepiColombo ƒ Further savings – Use of advanced detectors LaBr – Si drift detector instead of PMTs Si Drift – Miniaturised PD electronics PMT FPGA ƒ 2.5kg, ~2W APD SDD

15 of 36 Multifunctional Particle Spectrometer

40 mm

Position sensitive Si sensors

Scintillator 30 mm

Photodiode

ƒ Example for advanced measurement concepts ƒ Particle identification by (dE/dx), particle energy (α, β, γ, ions) & direction ƒ Smart configuration and smart readout concept ƒ Miniaturised electronics using ASICs and FPGA ƒ ~1kg, ~2W

16 of 36 Imaging X-ray spectrometry

ƒ BepiColombo Mercury Imaging X-ray Spectrometer ƒ Concept: Wolter-I optics ƒ Impossible without advanced miniaturisation technologies – Micro pore optics – Room temperature X-ray detectors with high resolution – Miniaturised readout electronics ƒ Problem: 1m focal length ƒ Needs to be well integrated into spacecraft ƒ Suitable for UV spectroscopy / photometer ƒ Need photon counting UV detectors (MCP with sufficiently sensitive photocathodes over large spectral range)

17 of 36 Imagers / cameras

ƒ Typical need – Aperture 50 to 100 mm – 10m resolution @ 400km distance – Focal length 60mm ƒ Limiting factors – Readout noise – Pixel size – Fillfactor – Dark current – Optical quality – Radiation hardness – Size of electronics ƒ Solutions – Advanced sensors and 3d packaging or stacking (see IMEC talk this conference) – Mirror optics (broad spectral range) – ASIC and FPGA technology – Combination with other receiver instruments possible (share receiver optics with laser altimeter and/or IR spectrometer or radiometer) – Integration of stereo function

18 of 36 NIR spectrometers

ƒ Target investigations – Mineralogy either NIR or MIR – Imaging ¾ Spectral resolution of ~1% – Atmoshpheric research ¾ Spectral resolution 10000 ƒ Technologies needed – Low noise CMOS CZT detectors – Linear variable filters – Tunable gratings (MEMS) – Immersed gratings – Advanced FTS technologies – Micro coolers – Integrated radiators ƒ Most technologies are US dominated technologies ƒ ESA is catching up

19 of 36 MIR imaging spectrometer / radiometers

ƒ Target investigations – Thermal inertias – Surface temperature – Dynamic processes (thermal imaging) ƒ Technologies needed – Micro bolometers – Micro coolers – Filter technologies – Low power scanning mirrors – Small and accurate blackbodies ƒ Problems – MEMS technologies mostly COTS – Need space qualification in time – Need to improve the performance – Not so well suitable for colder objects

20 of 36 Uncooled microbolometers

ƒ Development / qualification for BepiColombo ƒ Best performance achievable, but just about sufficient

– Mercury is rather hot SNR versus temperature – S/N ratio is fine for temperatures 600 >300K 7 microns – COTS device needed still 500 10.5 microns considerable 14 microns improvement of existing 400 technology 300 – Thermal stabilisation and SNR packaging rather critical 200

– Operation at different 100 instrument temperatures needs different calibrations 0 and settings 100 200 300 400 500 600 700 Temperature (K)

21 of 36 From COTS to Space Qualification

ƒ Sensor enhancements – AR coating required – Tuning of cavity for particular spectral range ¾ Needs in principle new bolometer design – Optimisation of bridge resistance (length, thickness) ¾ More sensitivity requires smaller bridge ¾ More fragile and susceptible to vibrations – Optimisation of electronics readout scheme ¾ COTS dedicated to video applications ¾ Space applications demand other frequencies – Minimisation of electronics noise ƒ Filter adaptation required ƒ Qualification of the device is presently performed ƒ Used as well for EarthCare (different format)

22 of 36 NIR/MIR spectrometer with radiometric function

ƒ NIR and MIR functionalities can be combined although thermal requirements and cooling requirements are sometimes different ƒ Calibration more difficult in integrated system ƒ Considerable mass saving possible BepiColombo baseline design ƒ Usually one spectral range NIR branch comes almost for dominating the technical free challenge ƒ ~2kg, 10W Radiometry comes almost for free 23 of 36 Active remote sensing

Microwave and radar technologies rather advanced these days

Not our business

Therefore, focussing on laser and LIDAR technologies

24 of 36 Laser technologies

ƒ Development of microchip lasers – Laser altimetry / distance measurements – Laser mass spectrometers – RAMAN/LIBS – LIDAR technologies

25 of 36 Microchip laser developments

ƒ Initiated by development of the laser mass spectrometer ƒ Breadboard existing in the SCI-PAI laboratorium equipped with MicroChip laser ƒ Several types of laser under investigation for LMS – 10 uJ green, 20 uJ red, 40 uJ goal ƒ Development of mJ laser under lead of cosine for ExoMars RAMAN/LIBS breadboard (ESA/TNO) – 1 mJ, <1W, 100 Hz, M^2 ~1.3, ∆t~ 1 ns ƒ µJ laser can be used for photon counting laser altimeter (verified by calculation) – 40uJ, 3W, 10 to 20 kHz, M2 ~1.1, <1ns

26 of 36 Advanced laser altimetry

ƒ Photon counting principle ƒ Lower mass by factor of up to 10 ƒ Low power (microchip laser) ƒ Single Photon Avalanche Diode (SPAD) ƒ Potential applications – Jupiter’s moon Europa – Landing systems – S/C formation control systems ƒ Useful in other fields – Earth observation (LIDAR, altimetry) – Environmental screening UAV – Military

27 of 36 High integration – small is beautiful

ƒ Advantages – Sharing of resources – Centralisation of electronics units ¾ Interesting for shielding purposes – Use of common entrance port – Use of common structure – Coalignment advantages – Shorter pathes and less wires ƒ Disadvantages – Complexer instruments ¾ Thermal ¾ Strucutral ¾ AIV ¾ Electrical – More difficult to manage ƒ Difficulties remain mainly with payload builders ƒ Small and competent team can manage integration

28 of 36 Example: Stereo Imaging Laser Altimeter

ƒ SILAT – Stereo imaging laser altimeter – Laser altimeter ¾ Photon counting ¾ 1ns, 0.3m resolution ¾ 10 to 20 kHz ¾ 3W laser – High resolution camera ¾ 10m @ 400km ¾ APS 2k x 2k pixels ¾ 3 colours ¾ 4ms readout – Stereo camera ¾ APS 1k x 1k pixels ¾ 1 colour ¾ 27 deg inclined – Electronics made extremely compact – Mass saving by integration factor ~2 – Still: Mass increases for radiation environment of Jupiter by factor of ~1.5 to 2

29 of 36 µChip laser Very compact, many parts

S-CAM

Laser Tx

CSiC structure

Mirrors omitted

HRC APS sensor LAT APD unit FPGA RTAX 2000 30 of 36 Main Electronics Unit

ƒ Common Power Supply ƒ Redundant DPU ƒ DPU and front-end fairly miniaturised ƒ Miniaturisation need: power supply and secondaries

31 of 36 Advanced payload technologies – enabling missions of the future

Cluster II

Venus Express

32 of 36 MicroSatellites – in future perhaps more than a test platform

ƒ Powerful planetary payloads are in principle small enough to fit onto MicroSats and could lead low cost missions with significant science return ƒ This leads to the possibility of synergies and co-development ƒ Presently studying 15kg class satellite with sufficient stability and capacity (compare previous talks) ƒ Train concept offers expandable missions and enhanced coverage

33 of 36 Conclusion

ƒ Miniaturisation is very welcome for science missions ƒ It enables missions to benign places such as Mercury, Jupiter and beyond ƒ Advanced remote sensing concepts and technologies are still at the very beginning and need to be matured to become applicable ƒ Need miniaturised standard components (connectors, cables, electronics, supply units)

34 of 36 Thanks to all colleagues!

ESTEC SCI-PA (now Frédéric Safa) Peter Falkner, Didier Martin, Marcos Bavdaz, Nicola Rando, Alan Owens, …

MECON Klaas Wielinga, Erik Kroesbergen

Swiss Space Technology Julian Harris

Monocrom Miguel Galan

Cosine Mark Bentley, Sandro Hannemann, Frederik Varlet, Erik Maddox, Dimitris Lampridis, Marco Beijersbergen

35 of 36 cosine

Applied Physics & Measurement Technologies

Intelligent. Passionate.

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