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No. 162 - Start of Quadrature Phase

No. 162 - Start of Quadrature Phase

Report for Period 14 December to 20 December 2008The Venus Express spacecraft entered nominally in the quadrature phase - the period during which the Sun-Spacecraft-Earth angle is between 75° and 95°. During the quadrature phase revised operating constraints on the VMC lead to the necessity for changing the spacecraft attitude to prevent unacceptable illumination of the VMC. To achieve this attitude fake ephemerides on the positions of the spacecraft and the Earth are uploaded to Venus Express. The first tilted communications pass was on 19 December 2008.

Later in the quadrature phase a swap to high gain antenna 2 (HGA2) is required for Earth communications, as the spacecraft attitude for continuing the use of HGA1 would result in illumination of spacecraft faces not designed to cope with such exposure.

Nominal operations were conducted during the reporting period. VIRTIS continues to be operated in the visual channels only. Radio Science Investigation (RSI) occultation measurements were taken during three ground station passes in the reporting period.

The table below shows a chronology of the main activities:

MET (Day) Date DOY Main Activity
1132 14/12/08 349

Communications pass over Cebreros

1133 15/12/08 350

Communications pass over Cebreros.
RSI occultation measurements pass over New Norcia.
HGA1 S-band carrier power test

1134 16/12/08 351

Skipped communications pass over Cebreros

1135 17/12/08 352

Communications pass over Cebreros.
RSI occultation measurements pass over New Norcia

1136 18/12/08 353

Communications pass over Cebreros

1137 19/12/08 354

Communications pass over Cebreros.
RSI occultation measurements pass over New Norcia.
Entry in quadrature

1138 20/12/08 355

Skipped communications pass over Cebreros.

At the end of the last Cebreros pass in the reporting period (DOY 355) Venus Express was orbiting Venus at 130.74 million km from the Earth. The one-way signal travel time was 435.8 seconds.

Payload Activities

ASPERA
The instrument was regularly operated as part of the routine plan.

MAG
The instrument was regularly operated as part of the routine plan.

PFS
The instrument was not operated during the reporting period.

SPICAV
The instrument was regularly operated as part of the routine plan.

VeRA
RSI occultation measurements were taken during the reporting period on DOY 350, 352 and 354 with the New Norcia ground station.

VIRTIS
The instrument was regularly operated as part of the routine plan.
VIRTIS is operated in the visual channels only.

VMC
The instrument was regularly operated as part of the routine plan.

Future Milestones

  • Handling of leap second on 1 January 2009.
  • High gain antenna swap from HGA1 to HGA2 on 13 January 2009.
  • The quadrature phase will end on 25 January 2009.
  • Commissioning of the Reaction Control Subsystem B on 12 February 2009.
  • Battery Deep Discharge Test is planned for 22 April 2009.
  • Start of next (outbound) quadrature phase on 29 May 2009.

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Legal disclaimer
This report is based on the ESOC mission operations report, MOR #162. Please see the copyright section of the legal disclaimer (bottom of this page) for terms of use.

Last Update: 1 September 2019
29-Oct-2020 17:29 UT

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