Jacques van Oene
April 2nd 05, 10:18 AM
Rosetta back in Cruise Mode
31 Mar 2005 12:18
Report for the period 11 to 25 March 2005
The reporting period covers the last few post-Earth swing-by spacecraft
configuration activities and some delta-commissioning operations on the
payload as agreed in the Commissioning Review of December 2004.
The spacecraft was gradually re-configured to cruise mode in various steps:
on 11 March the X-band link was re-established via the HGA; three On-Board
Control Procedures (OBCPs) were updated on 15 March and the antenna to be
selected for Survival Mode was changed back to MGA on 24 March.
In addition the periodic Attitude and Orbit Control System (AOCS) checkout
was carried out on 17 March; on this occasion the AOCS was configured back
to 3 reaction wheels and 1 IMP gyro, as planned for cruise. On 24 and 25
March slews were performed to characterise the disturbance torques in the
upcoming Near Sun Hibernation Mode (NSHM) attitude.
All spacecraft activities were carried out successfully and the spacecraft
performance remains excellent.
On the payload side, in the reporting period two outstanding commissioning
activities were carried out.
The boresight calibration of VIRTIS-H (VIRTIS - High resolution optical
subsystem) on 16 March, for the third time did not succeed in determining
the instrument boresight. The PI Team is investigating the problem.
The ROSINA activities covered upload of the new on-board software to the
redundant Data Processing Unit (DPU) and more troubleshooting of the
Reflectron Time of Flight Spectrometer (RTOF). The activities were
successfully completed but more calibration and parameter setting work will
be required in the future in order to stabilise the ROSINA RTOF instrument
functions.
A total of 9 New Norcia passes of a fixed duration of 7 hours commanding
were taken (four passes per week). A total of 7 DSN tracking passes were
taken until 18 March. This completed the DSN support for Rosetta Earth
swing-by 1.
The table below shows a chronology of the main activities in the reporting
period:
New Norcia PassDateDOYMain Activity
37611.03.05070Switch to X-band HGA, TC Link Monitor to 9 days
-12.03.05071DSN Tracking pass
-13.03.05072DSN Tracking pass
37914.03.05073Monitoring pass
38015.03.05074Move ROSINA/RTOF cover, ROSINA SW files, OBCPs maintenance
38116.03.05075Monitoring pass, dump VIRTIS science
38217.03.05076AOCS checkout, go to 3 wheels, 1 IMP, ROSINA/RTOF temperature
check
38621.03.05080ROSINA SW update, ROSINA delta-CVP pass 1
38722.03.05081ROSINA delta-CVP pass 2
38823.03.05082ROSINA delta-CVP pass 3, uplink Payload Passive Checkout 0
Mission Timeline (MTL)
38924.03.05083Set MGA strobing in System Initialisation Table (SIT), dump
Solid State Mass Memory bad block info
At the end of the last New Norcia pass in the reporting period (DOY 083)
Rosetta was at 6.73 million km from the Earth. The one-way signal travel
time was 22.4 seconds.
--
--------------
Jacques :-)
www.spacepatches.info
31 Mar 2005 12:18
Report for the period 11 to 25 March 2005
The reporting period covers the last few post-Earth swing-by spacecraft
configuration activities and some delta-commissioning operations on the
payload as agreed in the Commissioning Review of December 2004.
The spacecraft was gradually re-configured to cruise mode in various steps:
on 11 March the X-band link was re-established via the HGA; three On-Board
Control Procedures (OBCPs) were updated on 15 March and the antenna to be
selected for Survival Mode was changed back to MGA on 24 March.
In addition the periodic Attitude and Orbit Control System (AOCS) checkout
was carried out on 17 March; on this occasion the AOCS was configured back
to 3 reaction wheels and 1 IMP gyro, as planned for cruise. On 24 and 25
March slews were performed to characterise the disturbance torques in the
upcoming Near Sun Hibernation Mode (NSHM) attitude.
All spacecraft activities were carried out successfully and the spacecraft
performance remains excellent.
On the payload side, in the reporting period two outstanding commissioning
activities were carried out.
The boresight calibration of VIRTIS-H (VIRTIS - High resolution optical
subsystem) on 16 March, for the third time did not succeed in determining
the instrument boresight. The PI Team is investigating the problem.
The ROSINA activities covered upload of the new on-board software to the
redundant Data Processing Unit (DPU) and more troubleshooting of the
Reflectron Time of Flight Spectrometer (RTOF). The activities were
successfully completed but more calibration and parameter setting work will
be required in the future in order to stabilise the ROSINA RTOF instrument
functions.
A total of 9 New Norcia passes of a fixed duration of 7 hours commanding
were taken (four passes per week). A total of 7 DSN tracking passes were
taken until 18 March. This completed the DSN support for Rosetta Earth
swing-by 1.
The table below shows a chronology of the main activities in the reporting
period:
New Norcia PassDateDOYMain Activity
37611.03.05070Switch to X-band HGA, TC Link Monitor to 9 days
-12.03.05071DSN Tracking pass
-13.03.05072DSN Tracking pass
37914.03.05073Monitoring pass
38015.03.05074Move ROSINA/RTOF cover, ROSINA SW files, OBCPs maintenance
38116.03.05075Monitoring pass, dump VIRTIS science
38217.03.05076AOCS checkout, go to 3 wheels, 1 IMP, ROSINA/RTOF temperature
check
38621.03.05080ROSINA SW update, ROSINA delta-CVP pass 1
38722.03.05081ROSINA delta-CVP pass 2
38823.03.05082ROSINA delta-CVP pass 3, uplink Payload Passive Checkout 0
Mission Timeline (MTL)
38924.03.05083Set MGA strobing in System Initialisation Table (SIT), dump
Solid State Mass Memory bad block info
At the end of the last New Norcia pass in the reporting period (DOY 083)
Rosetta was at 6.73 million km from the Earth. The one-way signal travel
time was 22.4 seconds.
--
--------------
Jacques :-)
www.spacepatches.info