26 Mar 2007 17:00

All activities have been conducted according to the plan without major problems except for the Rosina RTOF (Reflectron type Time Of Flight mass spectrometer) sensor which is showing anomalous behaviour already seen earlier. Jupiter observations with the ALICE instrument will continue until May.

The navigation campaign after the Mars swing-by is continuing with the preparation of the Deep Space Manoeuvre 3 planned for 26 April 2007.

A total of 13 New Norcia passes (4x4h tracking only) were taken during this period. DSN support during the reporting period consisted in 4x4h tracking passes and concluded the support foreseen for the Mars swing-by phase. Tracking with DSN stations will be resumed in autumn for the Earth swing-by campaign.

At the end of the reporting period (DOY 082) Rosetta was at 302.1 million km from Earth (2.01 AU; one-way signal travel time was 16 minutes 48 seconds). The distance to the Sun was 227.1 million km (1.51 AU).

Science Results

In March last year, the OSIRIS instrument was used to observe asteroid 2867 Steins which Rosetta will perform a flyby of on 5 September 2008. See also the Rosetta status report no. 57 (linked from the right-hand side). Results of the gathered data have been presented in an article in Astronomy & Astrophysics by M. Küppers et al.

Date: 11 March 2006 Instrument: OSIRIS - NAC Description: Lightcurve of asteroid 2867 Steins, showing a rotation period of 6.052 h. Data was obtained during a continuous 24-hour period. From M. Küppers et al. [2007]

Spacecraft

Payload

The reporting period included the following activities:

• ALICE - Jupiter observation campaign
• ROSINA Delta-commissioning

ALICE
Operations have been conducted according to the plan without any major problem.

CONSERT
Nothing to report.

COSIMA
Nothing to report.

GIADA
Nothing to report.

MIDAS
Nothing to report.

MIRO
The memory dumps commanded as part of the previous test have been downlinked on DoY 075.

OSIRIS
Data retrieval operations for lost TM have been performed as requested by the PI on DoY 079.

ROSINA
The ROSINA RTOF sensor is not working as expected. RTOF checkout was conducted on DoY 079 and it was declared not successful. RTOF was automatically set to Stand-by mode.
At this point the PI team decided not to continue RTOF activities and the rest of the slot was dedicated to DFMS tests. The DFMS patch was applied and DFMS sequence 7 (gas calibration unit modes) started. DFMS sequence 1 was loaded for execution at 05:00 UTC on DoY 080. DFMS switch OFF was executed at 18:00 UTC on DoY 080. DFMS stayed ON outside coverage.

RPC
Nothing to report.

RSI
Nothing to report.

VIRTIS
Nothing to report.

Lander Philae
Nothing to report.

SREM
The instrument has been operated according to the plan.

Future Milestones

The Mars swing-by phase will be formally completed with the Deep Space Manoeuvre 3 and the orbit determination following it. The spacecraft timeline is now characterised by ALICE Jupiter observations.