Venus Express Payload Commissioning Continues
Report for Period 25 November to 01 December 2005
During the reporting period all the activities for the Near Earth Commissioning of the instruments have been conducted according to plan. The SPICAV instrument has been successfully switched ON for the first time.
In the course of this reporting period the first observations with a multi-instrument pointing scenario have been carried out with excellent results. This scenario is run completely off-line during non-coverage periods with payload inputs provided by the VSOC and merged with the spacecraft ones by the VMOC. Ground station contacts are limited to routine monitoring and science data downlink.
The table below shows a chronology of the main activities in the reporting period:
MET (Day) | Date | DOY | Main Activity |
17 | 25/11/05 | 329 | SPICAV NEC Pass |
18 | 26/11/05 | 330 | Uplink of full timeline for Pointing Scenario |
19 | 27/11/05 | 331 | SPICAV Sun Observation 1 |
20 | 28/11/05 | 332 | SPICAV Sun Observation 2 |
21 | 29/11/05 | 333 | SPICAV Sun Observation 3 |
22 | 30/11/05 | 334 | SPICAV/VMC UV Star Alignment Off-pointing |
23 | 01/12/05 | 335 | Stray Light Test 1 |
At the end of the last Cebreros pass in the reporting period (DOY 335, 20:00) Venus Express was 5.6 million km from the Earth, 144.4 million km from the Sun, and 63.2 million km from Venus. The one-way signal travel time was 18.5 seconds.
Payload Activities
ASPERA
The instrument is currently OFF and will be activated for the first time on DoY 343.
MAG
The instrument is permanently ON till the end of the NECP. During the pointing scenario some mode transitions have been successfully commanded.
PFS
The instrument is currently OFF and will be activated for the first time on DoY 338.
SPICAV
The instrument has been activated several times during the pointing scenario. The objective was to measure the alignment offsets between the various optical axes of the sensor unit and the spacecraft body axes. Sun observations were dedicated to the solar axes (apertures on side wall of the SC). The sensor has seen light on the three channels at different pointings. This allows the team calculating an approximate alignment offset for each of them, which will be refined in January during the second pointing test.
UV Star alignment was dedicated to the nadir axes. The sensor has captured a spectrum of the target star, Sirius, whose position on the UV CCD allows the determination of the alignment offset along one direction. The offset along the other direction will be obtained during the second pointing test, while observing a second star and the interplanetary Lyman-? radiation.
VeRA
The instrument has been activated as part of the pointing scenario on DoY 335 (Stray Light test).
VMC
The instrument has been activated as part of the pointing scenario on DoY 334 (UV Star).
Future Activities
Payload Commissioning will continue with the final part of the pointing scenario (Stray Light 2, Alignment Raster, and Alignment Off-pointing) and followed by the first activation of PFS.
