SWT 27/11/ Consert W.Kofman, A. Herique, JP. Goutail, A. Roux

SWT 27/11/ PC8 activities A large set of CONSERT test were performed during PC8 Theses operations are essential for CONSERT comet operation preparation.  RF link, Absolute Time Tag commands, OCN Interferences test and Long Ping Pong.  The FOP has been totally rewritten during PC8 preparation and the validation of the new FOP (comet-ready) has been done during PC8.  The CSA (CONSERT Synchronization Accuracy) has been implemented and was validated during PC8

SWT 27/11/

SWT 27/11/ PC8 results Figure 1: Consert power versus S/P position from -50/50 to +70/70° by 5° steps and power measured during the different PC tests.

SWT 27/11/ PC8 results CONSERT performances are nominal for OCN and LCN: the instrument works well. There is no unexpected TM-losses on the orbiter side: some minor modifications in the Fop have been done in order to avoid some ACK losses before time update. On the Lander, there are a few losses during long ping- pong test using mass memory. These limited losses are acceptable and Consert can be operated without inconveniences. Nevertheless, it is important for us to understand and to secure this problem. (CDMS ?)

SWT 27/11/ PC8 results Absolute Time Tag commands (necessary for CONSERT cometary operations) and RF link tests. The Lander synchronization was fine during all the operation including Time Tagged commands and RF link. The Orbiter operation shows a delay of 2~3 seconds. This delay seems stable and may be attributed to the OBCP management. Further investigations or tests have to secure this point.

SWT 27/11/ PC8 results: FOP tests All the tested sequences are fine. Minor modifications have to be done in order to take into account the timing of nested sequences. Some TC's have to be delayed (minimum 1 minute after OCN on) in order to avoid ACK without unvalid time stamp. User Manuel has to be updated in order to include a description of the typical data set for the new FOP.

SWT 27/11/ PC8 results: 10h duration ping-pong There is no drift observed between the Rosetta USO and OCN USO with an accuracy of 10 ms over 10 hours. Considering the Rosetta USO as a perfect reference at this scale, the OCN USO is 10 MHz with an accuracy of ~ There is no aging detected on the OCN USO. This is significantly better than the aging expected from the manufacturer specifications. There is no aging on the LCN USO. The LCN USO can be used as a 10 MHz reference with accuracy better than 10-6.

SWT 27/11/ PC8 conclusions PC8 is successful for Consert: - Our instrument is operational and the performances are nominal. - There are limited TM losses between LCN and CDMS. - The new FOP is operational, some minor correction are required in the timing. - CSA is an operational parameter of the greatest interest in order to secure / validate Consert operations. - Interference test has provided data of interest closing some doors and opening a lot of other doors… - The estimation of the OCXO aging is good

SWT 27/11/ PC9 results PC9 execution : start of February 09 OK Consert works well no problem detected during this test signal shape, noise level coherent

SWT 27/11/ Interference tests: General. Several instruments

SWT 27/11/ Interferences Miro Inconclusive. In fact on average the perturbation is negligible however there are sometimes short burst of perturbations (lines) increasing the noise level of 2-4 dBs. It is necessary to understand the reason of these bursts generated by MR.

SWT 27/11/ Interferences; VIRTIS and ? SCI data altered, noise level higher of about 5dB during the whole test. Line at 88.1 Mhz.

SWT 27/11/ Interferences (Group 1 in Susceptible Mode) Data altered by a high noise level of about 4 dB Strong line at MHz disappearing for 4 minutes starting at 13h49 accounting for 2 dB. Which instrument generates this line?

SWT 27/11/ PC10 -Basic tests (performed during each passive and active PC) -Unit functional test O and L - ping pong test with umbilical and orbiter schedulling - -Classical tests (each active PC) -Orbider schedulling with RF link -Abslute time tagged command (Lander schedulling) -Long ping pong test in « comet conditions » (30 h + 2h), need to check data storage capacity, different sampling, etc… - -test specific for PC10 -Interference test lander -Inerference testorbiter (delta PC8) -Delta fop commissionning -Test of the turn on synchroization accuracy requierement -Unexpeced 2s propagation delay on OBCP (TB nvestigated)

SWT 27/11/ ATTC Description -ATTC = Absolute Time-Tagged Command -OCN is scheduled by the Orbiter -LCN is Scheduled by the Lander -No other synchronization than absolute time of operation. -Objective : -To test the operational links necessary to modify absolute timing of both spacecrafts in real time. -During PC10 -Modification issued by CN Team short (?) time before execution. -Test of the RMOC LCC SONC part -During Lutetia Flyby -Modification issued by real time orbital update. -Test including the FDy part.