ASPOC & PICAM
IWF/ÖAW GRAZ 1
Main task
Development of hard- and software for flight instruments
Main research topics
1. Magnetospheric MultiScale
Development of the Active Spacecraft
Potential Control (ASPOC)
PI-ship (R. Nakamura)
2. BepiColombo
Development of the Planetary Ion CAMera (PICAM)
Sensor PI-ship (H. Lichtenegger) MMS stacked for vibration test
Lead: Harald Jeszenszky & Gunter Laky
Members
Staff: G. Fremuth, F. Giner, C. Kürbisch, M. Leichtfried, G. Prattes, R. Wallner
Cooperation within IWF
Magnetotail Physics (Nakamura et al.): MMS mission planning
SW-Atmosphere (Lammer et al.): BepiColombo mission planning
Space magnetometers (Magnes et al.): Magnetic cleanliness, parts
Exchange of know-how with all instrument developers
Key external collaboration
Italy: IAPS; Germany: MPS; France: LATMOS-SA; Hungary: Wigner RCP RMKI; Ireland: University of Ireland at Maynooth; Austria: FOTEC;USA: Southwest Research Institute
Who are we?
IWF/ÖAW GRAZ 2
IWF/ÖAW GRAZ 3
Operating principle
Caused by the equilibrium of various charging currents on a body embedded in plasma, the S/C gets positively charged and severely disturbs measurements of the plasma environment.
ASPOC emits a beam of positive indium ions at variable currents, keeping the S/C potential <+4 V. This ensures effective and complete acquisition of the ambient plasma distribution functions.
Instrument components
Electronics box (DPU, DC- and HV-converter board)
Two emitter modules, each containing 2 emitters
External harness between box and modules (LV, HV)
A system of dry nitrogen purge lines
Ion emitter consists of emitter capillary, indium reservoir and a heater element
ASPOC: Active S/C Potential Control
Emitter module cross-section
Spacecraft potential is controlled by two ASPOC instruments (~6 keV, ~10-50 µA), pointing in antiparallel directions for achieving maximum possible symmetry
Supports high-quality plasma and field measurements in NASA's Magnetospheric Multiscale (MMS) mission
4 satellites are operating in close formation
Group leads investigation, designed DPU board and S/W, integrated and tested9 Flight Models (8 FM’s delivered to NASA, spare FM kept for reference measurements)
Challenges: Simultaneous manufacture, test and operation in Europe and the US
Torkar et al., 2014, Active S/C Potential Control Investigation, Space Science Reviews, 10.1007/s11214-014-0049-3
IWF/ÖAW GRAZ 4
ASPOC for Magnetospheric Multiscale
Geometry of the ion beams
ASPOC instrument
Concept
All-sky camera for ions in Mercury's exo-ionosphere
3D velocity distribution and mass spectrum for ions over a full 2π FOV, up to ~3 keV energies and in a mass range extending up to ~132 amu
Key elements
Ellipsoidal electrostatic mirror M1 for focusing charged particles
Toroidal electrostatic analyzer for the energy selection by pass-band
Gate electrodes for providing start time for the time of flight (TOF)
Multi channel plate for detecting the ion impact as to both TOF and imaging
IWF/ÖAW GRAZ 5
PICAM: Planetary Ion Camera
Schematics of the ion optics
PICAM is part of the SERENA suite of four sensors.
Joint development with contributions from
France (detector, ion optics)
Germany (high voltage control, gate driver)
Hungary (DC converter)
Ireland (electronic box)
IWF leads the investigation and is responsible for
digital processing unit and ion optics
flight software and EGSE
mechanical and electrical integration
functional testing and environmental testing
performance calibration
IWF/ÖAW GRAZ 6
PICAM for Bepi Colombo
PICAM flight model
DPU flight board
Mechanical and electrical integration
Demanding requirements as to mechanical fitting accuracy, harness routing, general handling and cleanliness
Functional and performance testing
Operational parameters for electrodes as crucial point for the overall performance
Test facilities
High variance as to beam elevation (~90°), beam azimuth (~20°), unit rotation (~360°) and input parameters (electrode voltages) as challenge for the ion gun test facility IWF/ÖAW GRAZ 7
PICAM: Integration and Testing
PICAM sensor cross section
Current measurements
MMS ASPOC
Ground testing, operations planning until launch in March 2015
In-orbit commissioning, followed by routine operations of 8 instruments
Science data analysis (Nakamura et al.)
BepiColombo PICAM
Delivery of PICAM FM by the end of 2014
Refurbishment of PICAM QM as flight spare
Support of tests on observatory level
Performance testing and verification of PICAM flight spare including performance modelling
Support of the overall planning on mission level and SERENA level
Future Plans: 2015-18
IWF/ÖAW GRAZ 8
PICAM QM on MPO
IWF/ÖAW 9
Thank you