VIPER:A Plasma Wave Detection Instrument onboard Indian Venus Orbiter Spacecraft

Plasma waves are observed in almost all the solar system objects - planets, their satellites, comets, Sun, interplanetary medium, etc. The planetary ionospheres are capable of sustaining plasma waves which are observed there and play an important role in the ionospheric dynamics by propagating energy across different space regions and provide acceleration to particles to attain high energies for transportation. The study of planetary plasma waves also provides information on the solar wind - planet interaction, the energy distribution in the ionospheric plasma of that planet, etc. Venus does not possess a global magnetic field unlike Earth. Thesolar EUV radiation ionizes the neutrals and generates a plasma environment around Venus which can sustain plasma waves. Very few attempts are made to observe all plasma waves that can exist around Venus and that too with instruments having a limited dynamic range such as with PVO (Pioneer Venus Orbiter) and Venus Express. However, there are some other plasma waves which can exist around Venus but are yet to be observed. ISRO is planning to send an orbiter mission to Venus in near future where a suit of instruments named VIPER (Venus Ionospheric Plasma wavE detectoR) is onboard to observe Venusian plasma waves. The plasma wave observations around Venus and VIPER onboard ISRO's Venus Orbiter Spacecraft are discussed in this paper.