Venus Express ASPERA-4 Electron Spectrometer (ELS) Post-Launch Operations

Lead Research Organisation: University College London
Department Name: Mullard Space Science Laboratory


The ESA Venus Express mission to our sister planet is due for launch in October 2005. With the ASPERA-4 instrument we will study the solar wind interaction with the planet. In particular, as Venus (like Mars) has no magnetic field, we will study the processes which lead to the loss of the Venus atmosphere to space via the solar wind interaction. The comparison of this to the case of Mars will be particularly interesting since the surface pressure of the Martian atmosphere is about two orders of magnitude lower than Earth's while the Venusian atmosphere is almost two orders of magnitude higher than Earth's. Ultimately the comparison will tell us about the differences in resupply of material to the atmosphere. The electron measurements will play a key role in the determination of natural plasma boundaries; of processes in the different regions of the interaction, e.g. flux ropes and tail structure and in the determination of electric fields which may play a role in ion escape. In this application we request the resources needed to run the electron spectrometer for the nominal mission at Venus (500 days from April 2006). The tasks include instrument health evaluation, in flight calibration, planning, command generation, ground system development and engineering model support measurements. This includes all the work necessary to provide the parameters needed for scientific use of the data.


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