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