1. SESAME Status, Science goals and On-Comet Activities
K. Seidensticker1, H.-H. Fischer2, K. Thiel2, I. Apathy3, W. Schmidt4
and the SESAME team
1DLR (Köln) , 2University of Köln, 3KFKI (Budapest), 4FMI (Helsinki)

2. Outline of Talk Flight operation Software
Past activities, vibrations and PC #4
Software
Flight SW, AliBaba and Commanding SW
Hardware, documents and meeting
Funding and personnel
SESAME science objectives and measurements
SESAME objectives and Rosetta science themes
On-Comet operation aspects
Conclusions
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

3. Flight operation: Last activities
Standard operation:
SESAME Cruise Functional Test as part of Philae Extended AFT PC
Dates
Remarks
29. Mar. 2005
OK! External vibration measured 1
4. Oct. 2005
OK! External vibration measured, strong 6.7 Hz beat on two axes. All foot temperatures below °C 2
7. Mar. 2006
OK! External vibrations measured: Frequencies from 90 to 200 Hz 3
29. Aug. 2006
OK! External vibrations measured: Frequencies from 70 to 150 Hz. Higher foot temperatures
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

4. External vibrations Possible signal sources:
Orbiter reaction wheels
High gain antenna
Solar arrays
SESAME internal effect
etc.
Further analysis reasonable
CASSE sensitivity
Vibration pathways
Orbiter monitoring
Preparation for flywheel interference test
FFT of CASSE ACC signal from foot -Y, x-axis. Philae Checkout #1 (4. Oct. 2005)
Insert: Time series (total duration : 1000 ms)
Vibrations at and Hz ==> beat with 6.7 Hz
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

5. Next Activities: Philae Checkout #4
Planned SESAME procedures (LIORs):
Cruise Functional Test 2 (CFT-2)
Upgraded CFT, performs CASSE Listening before Sounding
Vibration Analysis (LSE-VA)
Various Listening commands for better vibration characterisation; also suitable for Philae flywheel IF test
WOL-Measurement (LSE-WM)
Attempt to measure vibration and rotation changes caused by Rosetta WOL
CASSE Calibration: Gain (LSE-CCG)
Sequence to verify amplifier settings and ADC curve; sound transfer from foot -Y to foot +X through folded landing gear
EEPROM Refresh (LSE-EERE)
Back-up: Software upload
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

6. PC #4: WOL sequences SESAME procedure WOL (ca. 2 hrs) Rosetta timeline
Thruster firing observed with ROSINA /COPS during Rosetta reaction wheel offloading (WOL)
From ROSINA web-site:
SESAME
procedure
LSE-VA
LSE-WM
LSE-VA
Thruster firing
Rosetta
timeline
WOL (ca. 2 hrs)
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

7. Flight software: Status and Upgrade
Flight software FM 1 is running flawlessly (within the known limits)
Major upgrade as version FM 2 (improved on-comet operation)
CASSE: New Triggered Mode: detection of external signals like cometary quakes and MUPUS-PEN insertion
CASSE: Fixing of wrong channel assignment (due to FPGA program flaw)
DIM: Autonomous measuring depending on dust flux and sensor status
PP: Improved data sampling strategy for PP active and passive modes
General: HK data content improved; time-stamp included; science data processing revised
FM 2 release during first half of 2007
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

8. Ground Software EGSE software “AliBaba” for SESAME
Goals:
Quick-look data check (science data and HK)
For all hardware versions in use (FM, GRM, lab)
Browsing on telemetry level
Version ready
Fully qualified for all PC #4 SESAME procedures
Planned AliBaba upgrades
Improved presentation of PP and DIM data
Improved service for lab operation: handle increasing file size
Export of instrument data (PDS format: TBD)
Adaptation to flight software version FM 2
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

9. S/W: Commanding and Instruments
Operation planning and commanding tool
Resource calculation for CASSE operation during PC #4 LIORs
CASSE Jobcard generator
New program planned
Generation of commands and command sequences (LIORs)
Calculation of resources (data volume, power, duration)
Calculation of related parameters to optimize command settings
Instruments
PP: Conversion software from SESAME raw-data (rolbin) to complex permittivity functions for any Philae geometry developed.
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

10. Hardware SESAME Central Electronics (CE) SESAME Lab Landing Gear DIM
Upgrade of SESAME EQM2-CE; for lab measurements
New SESAME GRM2-CE (flight functionality)
For further flight software development
New CASSE GRM2-PCB delivered in May 2006 (compatible to Philae GRM PCB)
SESAME Lab Landing Gear
Revised feet; new harness; integration of PP and CASSE sensors
DIM
Enhanced Ground Support Equipment (EGSE) (flight quality)
Flight evaluation, calibration and model improvement
Lander GRM-PCB modification for full flight compatibility
Removal of over-current protection PP
PP Lab-GRM PCB flight compatible
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

11. Documents ESA Archive Interface Control Document (EAICD)
One common document for CASSE, DIM and PP
Version 0.50 (RO-LSE-DS-3102) delivered to SONC in November 2005
Progress stopped due to limited man-power. Next version after PC #4 (TBD)
Interaction Document (RO-LSE-TN-3403)
Describes SESAME interaction with other Lander units
Release of draft version 4.3 after discussion with MUPUS team
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

12. Meetings 1. Post-Launch SESAME workshop MUPUS - SESAME interaction
October 2005, KFKI, Budapest
Status, scientific results, S/W and operation planning
MUPUS - SESAME interaction
16. February 2006
Improved data interface agreed
Draft version of upgraded interaction document delivered
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

13. Funding and Personnel CASSE / SESAME DIM PP
Large changes at DLR possible; people and test units relocation?
Personnel: DLR: K. Seidensticker (PI), K. Gusbeth (student, Ground S/W), Univ. Köln: K. Thiel, H.-H. Fischer (Co-Is, Flight S/W, operation)
DIM
New Co-Investigator: M. Podolak (Tel Aviv University)
Personnel (KFKI AEKI): I. Apáthy (PI), A. Péter, diploma student; A. Juhász (Co-I, KFKI RMKI) PP
In-house funding for Rosetta support, external funding for special activities on application
Personnel: FMI: W. Schmidt (PI), M. Genzer (operations), J. Ryno (S/W support); Co-Is: ESTEC: H. Laakso, R. Trautner; CETP: M. Hamelin
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

14. CASSE: Science Objectives and Measurements
LSE-CAS-O1: Determine elastic properties of cometary surface layer
LSE-CAS-O2: Determine macro-structure of surface layer (layering, inhomogeneities)
LSE-CAS-O3: Locate and analyze micro-seismic events
Measurements
LSE-CAS-M1: Determine longitudinal and shear wave velocities by active sounding from foot to foot
LSE-CAS-M2: Generate reflection and refraction seismograms by active sounding (CASSE and MUPUS-Pen)
LSE-CAS-M3: Register external signals with several sensors (Passive listening)
Relation to other Instruments
MUPUS: Use MUPUS-PEN hammering as external vibration source
SD2: Use SD2 drilling as external vibration source (TBD)
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

15. DIM: Science Objectives and Measurements
LSE-DIM-O1: Study the fluxes and dynamics of near-surface cometary particle flow
LSE-DIM-O2: Determine physical properties of cometary grains
LSE-DIM-O3: Contribute to the understanding of cometary activity and the formation of cometary mantles
Measurements
LSE-DIM-M1: Measure parameters of the electrical signal caused by particle impact on piezo-electric plate
LSE-DIM-M2: Determine average signal height in case single impacts can not be discriminated
LSE-DIM-M3: Determine flow rate and direction as well as temporal variations
Relation to other Instruments
GIADA: Correlate DIM data with GIADA observations (TBD)
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

16. PP: Science Objectives and Measurements
LSE-PP-O1: Determine electrical properties of the cometary surface matter and its evolution
LSE-PP-O2: Monitor electron density variation and the comet’s outgassing activity
Measurements
LSE-PP-M1: Inject alternating currents of different frequencies into the cometary surface and monitor variations of induced electrical potential (active mode)
LSE-PP-M2: Monitor potential difference variations (passive mode)
Relation to other Instruments
ROMAP: Compare permeability measurements
MUPUS: PP electrode deployment; temperature of surface matter
APXS: PP electrode deployment; surface composition
CIVA: Observation of MUPUS-Pen and Philae soles
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

17. SESAME and Rosetta Science Themes 1
1. Global Characterization of the Nucleus
D. Near Surface Distribution of Minerals, Organics and Ices
LSE-CAS-O1, LSE-DIM-O2, LSE-DIM-O3
E. Internal Nucleus Structure
LSE-CAS-O2, LSE-PP-O1
2. Composition of the Nucleus Material
A. Composition of Near-surface Minerals
LSE-DIM-O2
C. Composition of Near-surface Ices
LSE-DIM-O2, LSE-PP-O1
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

18. SESAME and Rosetta Science Themes 2
3. Physical Properties of Nucleus Material
A. Microphysical Properties of the Nucleus Material
LSE-CAS-O1, LSE-DIM-O2
B. Electric and Magnetic Properties of the Nucleus Material
LSE-PP-O1
D. Mechanical Properties of the Nucleus Material
LSE-CAS-O1
4. Development of Cometary Activity
A. Properties of Regions Emitting Gas and Dust
LSE-CAS-O3, LSE-DIM-O1, LSE-DIM-O3
B. Temporal Evolution of the Surface and Inner Coma
LSE-CAS-O2, LSE-CAS-O3, LSE-DIM-O3, LSE-PP-O2
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

19. SESAME and Rosetta Science Themes 3
5. Composition of Coma and Tail Material
C. Composition of Solid Particles
LSE-DIM-O2
6. Physical Properties of Coma and Tail Material
C. Physical Properties of Solid Particles
7. Interaction of Cometary Material with its Interplanetary Environment
B. Properties of the Ionosphere
LSE-PP-O2
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

20. On-comet operation Draft versions (straw-man) of command sequences
Descent
First Science Sequence (FSS)
Long-term operation
Next years: development and test of additional measurement and operation methods => further upgrade of flight software
Development of software planning tool for command generation and resource calculation
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

21. Operational interaction and constraints
CASSE
MUPUS: MUPUS-Pen used as a moving signal source during insertion (hammering)
SD2: Signal source during drilling (TBD)
Flywheel: Impact on CASSE operation to be measured during cruise phase PP
APX: Transmitter electrode; no operation during PP measurements
MUPUS: Transmitter electrode; no operation during PP measurements
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006

22. A difficult way to 67P/C-G: Conclusions
Slow progress due to limited resources
Software (flight and ground) upgrades are needed for full use of hardware
Improving operation and analysis methods, e.g.:
CASSE: Analysis of seismograms
DIM: More precise impact model
PP: More calibration work
Complex permittivity vs. ice concentration, composition, temperature
Detailed modelling of electrode configuration
Definition of SESAME science goals and measurements
2nd Post-Launch Philae Experimenters Workshop Helsinki, September 2006