SESAME Status and Cruise Phase Activities K. Seidensticker1, A. Péter2, H.-H. Fischer3, W. Schmidt4, K. Thiel3 and the SESAME team 1DLR (Köln), 2KFKI (Budapest), 3University of Köln, 4FMI (Helsinki)

Outline of Presentation SESAME flight performance Instrument status External vibrations Philae temperatures Cruise science Hardware upgrades Software development Archiving and PDS Financial situation Conclusions First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Flight Data Block Dates Procedure Remarks 1 March 2004 3 Lander AFTs Only HK data; no problems 2 April 2004 Procedure CV-FCP-234, V6 Executed in pass 4 Repeated in pass 5 to check for consistency and noise 3 May 2004 CV-FCP-234, V6 CV-FCP-234, V7 Interference runs for CONSERT and ROMAP Various Lander settings 4 October 2004 SESAME Cruise Functional Test Part of Philae Extended AFT External noise measured 5 March 2005 First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

CASSE Results CASSE performed as expected Forced HPC vs. LPC: no differences (TBC) TY-Ebox (+40°C vs. -8°C): no differences (TBC) No effect from CONSERT and ROMAP on CASSE Reproducible time series and FFT spectra CASSE signal and FFT of foot -Y Block 2, pass 5, fTRM = 998 Hz First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

DIM Results DIM performed as expected Forced HPC vs. LPC: no differences (TBC) TY-Ebox (+40°C vs. -8°C): no differences (TBC) No effect from CONSERT and ROMAP on DIM Noise up to acceptable upper limit (40 dB) Slightly increased average value (5 dB) during sensor test (block 2, pass 5): OK DIM noise during several passes: OK DIM Average-Continuous mode (block 3, pass 5): OK First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

PP Results PP performed as expected Forced HPC vs. LPC: no differences No RX offset and 50 Hz signal as with GRM Effect from CONSERT and ROMAP on PP could not be checked. Repetition of Active Mode test during block 3, pass 8 showed more noise. PP Health-Check data close to optimal values PP Active Mode test, fTX = 400 Hz (block 3, pass 5) No crosstalk between transmitter, current- and potential monitor, electronics functioning First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Block 4 External Vibration SESAME Cruise Functional Test (CFT) CASSE listening mode External signal (Orbiter gyros?) detected Observed on 6. October 2004 and 29. March 2005 Main frequencies: 171, 134, and 212 Hz CASSE signal (upper panel) and FFT (lower panel) of ACC of foot +Y Block 4, 6. Oct. 2004, CFT, fACC = 5993 Hz First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Philae Temperatures SESAME data of CASSE PCB and Philae feet sensors First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Sole Temperatures Temperatures of the -Y and +Y feet sensors during ROMAP IF test RX soles temperatures increase more rapidly than those of TX soles due to accelerometer warm-up. First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

CVP Measurements Summary SESAME operated as expected and within the limits set by the software version FM 1.0. An external signal with vibration frequencies of about 200 Hz has been found in Block 4 and 5 data. A flight S/W update is intended to overcome many of the deficiencies known before launch and observed during CVP. Time: TBD After the flight S/W update a delta commissioning is needed, especially to test long duration measurement modes of CASSE and DIM. First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Cruise Science Activities No Fly-By measurements are planned Experiments in laboratory, DLR Planetary Chamber and glacier Method development CASSE: e.g. analysis of external signals PP: Reference library of temperature, humidity and composition dependence of signal Instrument usage for other missions PP: Modified version is used on SMART-1, proposed for ExoMars CASSE: Use of Beagle 2 mole for acoustic sounding Optimization of ground based analysis and modelling is ongoing for all 3 instruments First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Lab Landing Gear SESAME Lab Landing Gear to be used for CASSE and PP Variable leg lengths: DLR Planetary Chamber Philae Landing Gear First measurement series in DLR Planetary Chamber in October 2004 Upgrade of mechanical design and harness needed SESAME Lab Landing Gear in DLR Planetary Chamber (September 2004) First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Hardware Upgrades SESAME Central Electronics (CE) DIM Upgrade of SESAME EQM2-CE; used for lab measurements New SESAME Lab GRM-CE (flight functionality); used for software development DIM Enhanced Ground Support Equipment (EGSE) (flight quality): flight evaluation, calibration and model improvement Lander GRM-PCB modification for full flight compatibility (removal of overcurrent protection) SESAME Lab Landing Gear First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

DIM EGSE Drop Mechanism and Sensor First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Flight Software FM 1.0 Released in March 2001; implements all user requirements known at that time Chiefly “step-by-step”-commanding of instruments operations via telecommands, i.e. little on-board autonomy Flight S/W FM 1.0 is reliable (one minor bug found) Currently active on SESAME FM; suitable for commissioning, sufficient for operations during cruise phase, limited capabilities for on-comet operations First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Upgrade: Flight Software FM 2 CASSE New Triggered Mode: detection of external signals like cometary quakes and MUPUS-PEN insertion Fixing 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 Sufficient for cruise phase; improved on-comet operations possible Release during first half of 2006 (?) First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Future: Flight Software FM 3 CASSE: new operation modes (e.g. on-board averaging and particle impact signal analysis) Extended range (< -105 °C) for foot temperature measurements using S/W “trick” (TBD) PP: digital filter routines for on-board data reduction Increased autonomy of operations (parameter selection) and optimized data reduction/compression Release date: ? First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Ground Software EGSE software “AliBaba” for SESAME PP ground software Quick Look data check (e.g. HK, time series, DIM) Export of instrument data Command generation (CASSE) PP ground software Permittivity calculation from raw data (ready) Fitting of PP signals to lab data to determine temperature, humidity and composition (planned) Instrument software simulator (ready) First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Delta Commissioning Next active check-out (Nov. / Dec. 2006): Upload of Flight Software FM 2 Test of EEPROM refresh command sequence Later on upload of Flight Software FM 3 (2008 or later) New interference test with CONSERT and ROMAP using Lander power supply First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Science Goals: Assessment (CASSE) Primary goal Measurement of sound velocities cp and cs in order to establish basic elastic soil parameters Laboratory experiments being performed to improve measuring methods and to evaluate parameter ranges for different soils. Secondary goals Detection of external cometary signals (temperature "cracks”, activity noise ...) Recording of particle impacts on foot soles during descent Active sounding to scan local surface layering and inhomogeneities at landing site Related operation modes presently being validated. First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Science Goals: Assessment (DIM) Detection of single particles (Burst Mode) No problems found, improvement of calibration planned Autonomous adaptation to a wide range of dust parameters in order to match different comet environments Not yet implemented and tested First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Science Goals: Assessment (PP) Primary goals Measurement of the complex permeability Water-ice content and its variability in the surface Surface temperature and its variability No problems foreseen in achieving these primary goals Secondary goal Monitoring of the comet’s outgassing activity Depends on allocated time for passive measurements Tertiary goal Electric fields, electron densities (3rd level goal) Only fast variations >10 Hz are detectable due to cable problem First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Archiving and PDS Archiving Planetary Data System (PDS) SESAME archive maintained on DLR FTP-Server Deimos (Documents, drawings, photos, S/W code etc.) Calibrated HK data on SONC web-server Planetary Data System (PDS) Definition of level 0 data format preliminary for CASSE, DIM and PP (RLGS-SPEC-SONC-SCI-136-CN) SESAME EAIC-document in preparation (one common document for CASSE, DIM and PP planned) Delay due to reduced man-power First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

Funding and Personnel CASSE / SESAME DIM PP Partly DLR in-house funding (one person), partly DLR external funding (Univ. Köln) Personnel: DLR: K. Seidensticker (PI), D. Madlener (student, Ground S/W), Univ. Köln: K. Thiel (Co-I, Flight S/W) DIM Partly by in-house funding, partly by ECS (European Co-operating States of ESA) until 2007 Personnel (KFKI AEKI): I. Apáthy (PI), A. Péter, A. Keresztúri, I. Tóth (working part-time); 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 First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005

It is a long way: Conclusions Flight hardware and software is operating as expected Software upgrades are needed to make full use of hardware Analysis and modelling methods have to be and can be improved, e.g.: DIM: More precise impact model CASSE: Signal propagation through soles and porous media Difficult situation (man-power and funding) for CASSE (including SESAME) First Post-Launch Philae Experimenters Workshop Teistungen, 4. - 6. April 2005