Venus Orbiter Mission (VOM)
Despite several space missions launched globally, the planet Venus retains its enigma. Early missions in the 1960s and 1970s by NASA and the Soviet Union revealed the planet’s scorching surface temperature and dense atmosphere. Later missions, such as Pioneer Venus and Vega, expanded our understanding of its atmospheric composition and circulation. More recent missions, like Venus Express and Akatsuki, focused on climate evolution and atmospheric dynamics.
However, these past missions had a major limitation: they only provided narrow spatial coverage, focusing mostly on the South-polar region or the equatorial belt. This made it difficult to build global maps of phenomena like winds, waves, and chemical abundances. The newly approved Venus Orbiter Mission (VOM) is designed to solve this by providing uniform, global coverage of Venus, creating a unique dataset for future science.
Key Scientific Objectives
The Venus Orbiter Mission will explore the planet’s atmosphere, its surface, and its interaction with the Sun. The primary scientific goals include:
- Examining dust particles present in the Venusian atmosphere.
- Mapping the surface topography in high resolution.
- Studying the solar X-ray spectrum near the planet.
- Analyzing the Venusian airglow.
- Investigating the sub-surface characteristics of the planet.
- Serving as a technology demonstration for the Indian Space Research Organisation (ISRO) by testing aerobraking and thermal management techniques in a harsh environment.
Mission Profile and Timeline
- Launch Date and Vehicle: The mission is scheduled to launch in March 2028 using the LVM-3 launch vehicle.
- Budget: The estimated cost of the mission is approximately 1236 Crore Indian Rupees.
- Orbital Journey: The spacecraft will first be placed in an Elliptical Parking Orbit (EPO) of 170 km x 36000 km around Earth. After a cruise phase, the Venus Orbit Injection (VOI) will capture the spacecraft in an initial orbit of 500 km x 60000 km around Venus.
- Aerobraking Phase: To save fuel, the spacecraft will use a technique called aerobraking for 6 to 8 months. “ This will slowly lower the spacecraft into its desired Science Orbit.
- Science Orbit: The final operational orbit will be a low altitude of 200 x 600 km with an inclination of around 90 degrees. The spacecraft will carry out scientific studies from this highly inclined orbit for a period of 5 years.a
Communication and Data Management
Once the spacecraft reaches its science orbit, it will begin collecting data.
- Data Reception: The DSN32 station of the Indian Deep Space Network (IDSN) will be used to communicate with the spacecraft and collect the science data. External agencies, such as NASA, will also provide network support to ensure maximum contact time.
- Data Archiving: The data will be received, processed, and archived at the Indian Space Science Data Center (ISSDC). It will be stored in the standard PDS4 format, making it easily accessible via the internet for scientists in India and abroad.
The Expert Review Committee has recommended 19 distinct payloads for this mission to address specific scientific gaps. These are categorized into Indian, Collaborative, and International instruments.
- Surface and Sub-surface Instruments (Indian)
- VSAR (S-Band Synthetic Aperture Radar): Maps the globe at a 20-30m spatial resolution to search for active volcanism and characterize impact craters.
- VARTISS (Venus Advanced Radar for Topside Ionosphere and Subsurface Sounding): A low-frequency radar that probes the topside ionosphere and investigates the stratigraphy of geological units and buried features.
- VSEAM (Venus Surface Emissivity and Atmospheric Mapper): A hyperspectral imaging spectrometer used to identify active volcanic hotspots and map clouds and aerosols.
- Atmospheric and Cloud Monitoring (Indian)
- VTC (Venus Thermal Camera): Maps thermal emission from cloud tops to understand atmospheric dynamics and planetary-scale features.
- VCMC (Venus Cloud Monitoring Camera): Studies atmospheric circulation dynamics and explores signatures of lightning.
- LIVE (Lightning Instrument for VEnus): Detects lightning and estimates its received energy in the Venusian environment.
- VASP (Venus Atmospheric SpectroPolarimeter): Investigates global circulation and the correlation between cloud top altitude and microphysical properties.
- SPAV (Solar occultation photometry): Measures the vertical distribution of aerosols and haze layers in the mesosphere.
- NAVA (Narrow band oxygen Airglow detection): Measures Venusian airglow emissions to investigate the nightside ionosphere.
- Ionosphere, Plasma, and Space Environment (Indian)
- VETHICA (VEnus THermosphere Ionosphere composition Analyser): Studies the altitude-latitude distribution of neutral and ion composition.
- VEDA (Venusian Electron temperature and Density Analyser): Measures electron density and temperature to understand variations in the ionopause altitude.
- RPA (Retarding Potential Analyser): Measures ion energy distribution to understand upper atmospheric plasma dynamics.
- VIPER (Venus Ionospheric Plasma wave detectoR): Samples the plasma and magnetic environment to characterize plasma waves.
- VeRad (Venus Radiation environment monitor): Studies the impact of high-energy solar energetic particles on the atmosphere.
- SSXS (Solar Soft X-ray Spectrometer): Measures the solar irradiance in the soft X-ray region entering the Venus atmosphere.
- VODEX (Venus Orbit Dust Experiment): Studies the abundance, flux, and distribution of Interplanetary Dust Particles near Venus.
- Collaborative and International Payloads
- VISWAS (India & Sweden): A Plasma and Neutrals Analyser designed to study solar wind interaction and the loss of the Venusian upper atmosphere.
- RAVI (India & Germany): Uses radio anatomy to study the thermal structure of the atmosphere and variations in the ionosphere.
- VIRAL (Russia): An infrared payload that retrieves vertical profiles of atmospheric density, temperature, and gases like Carbon dioxide and Water.
This ambitious mission is expected to create significant employment opportunities, foster skill development, and drive technological advancements across the country.
