ESA Science & Technology - No. 74 - Ongoing Preparations for Mars Swing-by

During the reporting period the following activities have been conducted:

• MIRO patched software (SW) test
• Lander EEPROM (Electrically Erasable Programmable Read Only Memory) updated for Mars swing-by observations
• SSMM corrupted block recovery actions
• OSIRIS SW corrective actions

All activities have been conducted according to the plan without any major problem. The navigation campaign for the Mars swing-by is proceeding according to the plan with radiometric data acquired by ESA (NNO: New Norcia) and DSN stations.

At the end of the reporting period (DOY 026) Rosetta was at 316.3 million km from Earth (2.11 AU; one-way signal travel time was 17 minutes 35 seconds). The distance to the Sun was 198.2 million km (1.32 AU).

Spacecraft

Payload
The reporting period included the following activities:

• DoY 018 - MIRO Patched SW test
  

  This test has been conducted in order to validate some SW patches to be applied at switch ON required to fix known problems. The patches were successfully tested, however, a foreseen reset event requires a modification of the test sequenced used and a full re-test will be conducted later.

• DoY 024 - Lander EEPROM updates for the Mars swing-by
  the Lander has been activated at 20:30 and some updates to the EEPROM tables have been performed in view of the observations to be done during the Mars swing-by.
• DoY 025 - OSIRIS SW patch
  This activity has been scheduled to apply a small SW patch to the SW of the instrument.

Science Results

Date: 3 December 2006 Instrument: OSIRIS Description: View of Mars against the background of our Galaxy, obtained by OSIRIS's Wide Angle Camera. Mars appears overexposed in this image.
Date: 2-3 January 2007 Instrument: OSIRIS Description: Sequence of images obtained during a 36-hour remote observation campaign of asteroid 21 Lutetia. Rosetta was at 245 million kilometres from the asteroid.

Future Milestones

The Mars swing-by phase formally started on 28 July 2006. The actual swing-by will take place on 25 February 2007, followed by a Deep Space Manoeuvre in April 2007. Preparation activities for the Mars swing-by will continue in the coming weeks with the following plan:

• DoY 031 Configuration of the IMP (Inertial Measurement Package, consisting of 3 gyros and 3 accelerometers to measure the spacecraft's attitude)
• DoY 039 Trajectory correction manoeuvre
• DoY 046 Spacecraft pre-configuration for Mars swing-by

The navigation campaign will continue its most dense phase with several tracking passes per week and DDOR measurements, both with ESA and DSN stations.

The ground segment has started the formal validation campaign for the Mars swing-by scenario with the first simulation, 4 additional ones are foreseen in the next weeks.