Payloads Home /Activities/Payloads
This page provides data on the payloads developed by the DoS. For the links to payloads developed by other institutes or agencies, corresponding mission page may be browsed.
The scientific or technological instrument carried on board a satellite for the specific purpose is termed as a payload. Payloads vary in their purpose, size, composition, capabilities, etc
Communication payloads
SAC is leading centre for design and development of payloads for communication and navigation satellites. The first experimental communication satellite of India, ‘APPLE’ was designed, fabricated and qualified at SAC. It was launched onboard the first experimental flight of the Arian. Since then centre has developed strong competence in design and development of communication payloads. Satellite Communication payloads consists of transponders. Transponders for INSAT and GSAT series of satellites are designed in various bands of UHF, L, S, C, Ext. C, Ku and Ka bands. The Geo Stationary Satellite (GSAT) is the operational series of communications satellites which provides fixed satellite services for Indian civilian use. SAC designs and develops the various subsystems of a communications transponder. List of communication payloads delivered here
Earth Observation payloads
After inception of SAC, soon the payloads development for Bhaskara 1 and 2 started taking place. Bhaskara-1 was a small satellite, weighing about 450 kg, compared to the later IRS spacecraft, and it carried two TV cameras operating in the red and near infrared spectral regions. Both the spacecraft were spin stabilized. The experience gained with the development of these two spacecraft as well as the processing of the data received was valuable in the development of future satellites. Since then SAC has delivered more than 50 electro-optical and microwave payloads.Over these decades, SAC has developed expertise in developing multi-platform, multi-spectral, multi-temporal, hyper-spectral, multi-resolution, day and night, and all weather Earth Observation payloads.
List of earth observation payloads delivered is here
Navigation payloads
The Satellite Navigation Payloads are aboard Indian Regional Navigation Satellite System (IRNSS). IRNSS envisages establishment of regional navigation system using a combination of GEO and GSO (Geosynchronous Orbit) spacecrafts. The IRNSS system is expected to provide position accuracy better than 20m over India and region extending about 1500 Km around India. IRNSS system is now called ‘NAVIC’ an acronym of NAVigation using Indian Constellation.List of navigation payloads delivered is here marked against IRNSS spacecrafts.
Scientific payloads flown aboard Indian launch vehicle stages:
Orbital Platform Experiments in PSLV (PS4-OP) is a novel idea to use the spent PS4 stage (fourth stage of PSLV) as a 3 axis stabilized microgravity environment for short duration scientific experiments. This is intended to carry out in-orbit scientific experiments for an extended duration of 4-6 months for small scientific payloads. The advantage of the platform is that the stage has standard interfaces & packages for power generation, telemetry, tele-command, stabilisation, orbit keeping & orbit manoeuvring.
Scientific payloads developed by DoS
Mars Orbiter Mission
Mars Orbiter Mission is ISRO’s first interplanetary mission to planet Mars with an orbiter craft designed to orbit Mars in an elliptical orbit. The primary driving technological objective of the mission is to design and realize a spacecraft with a capability to perform Earth Bound Manoeuvre (EBM), Martian Transfer Trajectory (MTT) and Mars Orbit Insertion (MOI) phases and the related deep space mission planning and communication management at a distance of nearly 400 million Km. Following are the payloads developed by SAC and flown.
MSM is designed to measure Methane (CH4) in the Martian atmosphere with PPB accuracy and map its sources. Data is acquired only over illuminated scene as the sensor measures reflected solar radiation. Methane concentration in the Martian atmosphere undergoes spatial and temporal variations. Hence global data is collected during every orbit.
This tri-color Mars Color camera gives images & information about the surface features and composition of Martian surface. They are useful to monitor the dynamic events and weather of Mars. MCC will also be used for probing the two satellites of Mars – Phobos& Deimos. It also provides the context information for other science payloads.
TIS measure the thermal emission and can be operated during both day and night. Temperature and emissivity are the two basic physical parameters estimated from thermal emission measurement. Many minerals and soil types have characteristic spectra in TIR region. TIS can map surface composition and mineralogy of Mars.
Chandrayaan-1
Scientific Payloads from India
Scientific Payloads from abroad
SARA on Chandrayaan-1
The Sub-keV Atom Reflecting Analyzer (SARA) experiment onboard Chandrayaan-1 mission was a joint Indo-Swedish collaborative research program between SPL-VSSC and Swedish Institute of Space Physics (IRF), Kiruna, Sweden with participation from Japan (JAXA), and Switzerland (University of Bern). The main scientific objective of the SARA experiment was to study lunar-solar wind interaction by means of the Energetic Neutral Atoms (ENAs) and the charged particles produced as a result of solar wind interaction with the lunar surface.
The three components of the SARA experiment were: two sensors - CENA (Chandrayaan-1 Energetic Neutral Analyzer), which detected low energy neutral atoms in the 10-3300 eV energy range, and the SWIM (Solar WInd Monitor), which measured the plasma flux in the near-lunar environment in the 10-3000 eV energy range, and the DPU (Digital Processing Unit) which commanded and controlled the operations on both the sensors. Both sensors had a fan shaped Field of View (FoV). Onboard commissioning of SARA was successfully completed in January 2009, and the planned normal operations began in February 2009.
Chase:
Flight Model of CHACE (from Sridharan et al., 2010)
The Chandra's Altitudinal Composition Explorer (CHACE) was one of the three experiments on the Moon Impact Probe (MIP) experiment on Chandrayaan-1. CHACE was a neutral mass spectrometer from SPL, VSSC. It had the scientific objective to study the latitudinal-altitudinal distribution of neutral composition on the sunlit side of the tenuous lunar atmosphere. CHACE performed well on November 14, 2008, both during the rehearsal phase and during the actual mission when the MIP was released from the mother spacecraft Chandrayaan-1 at 100 km from the Lunar surface, and had a free-fall along the 140-degree East longitude landing close to the Lunar South Pole at 89 degree. Observations were obtained with an altitude resolution of 250 m and a latitudinal resolution of 0.1 degree from 45N to 89-degree South latitude.
Chandrayaan-2:
CHACE-2
The CHandra’s Atmospheric Composition Explorer-2 (CHACE-2) experiment aboard Chandrayaan-2 orbiter was aimed to study in situ, the composition of the lunar neutral exosphere in the mass range 1–300 amu. CHACE-2 was on neutral gas mass spectrometer. CHACE-2 was sequel to CHACE on Chandrayaan-1 and MENCA on Mars Orbiter Mission. CHACE-2 observations will address the spatial and temporal variations of the lunar exosphere, and examine water vapour as well as heavier species in it. The observations have shown the first global distribution of Argon-40, which is an important noble gas, in the lunar exosphere.
RAMBHA-DFRS
The Radio Anatomy of Moon Bound Hypersensitive Atmosphere and Ionosphere – Dual Frequency Radio Experiment (RAMBHA-DFRS) experiment aboard Chandrayaan-II uses communication channel between Orbiter and ground in Radio Occultation mode to study the temporal evolution of electron density in the Lunar ionosphere.
It consists of a highly stable 20 MHz EMXO source, having a stability of the order of 10-11, which generates two coherent signals at X (8496 MHz), and S (2240 MHz) band of radio frequencies. The coherent radio signals, transmitted simultaneously from satellite, and received at ground based deep station network receivers would be used to study temporal and spatial variations in the Lunar ionosphere. the major science objectives of the experiments include, (a) to study the variations in the ionosphere/ atmosphere at Moon, (b) to explore if the Ionosphere at Moon is omnipresent or has episodic appearances and, (c) to confirm the source of the ions in the lunar ionosphere, whether dusty or molecular ions. According to the experiment, every two hours we will get one ingress and then one egress observations.
MENCA
Flight Model of MENCA (from Bhardwaj et al., 2015)
The Mars Exospheric Neutral Composition Analyser (MENCA) experiment was one among the five experiments onboard the Mars Orbiter Mission (MOM), the first Indian Mars mission. MENCA is a quadrupole mass spectrometer based scientific payload, capable of measuring relative abundances of neutral constituents in the mass range 1 to 300 amu, with unit mass resolution. In addition to acquiring the mass spectra in a specified mass range, the instrument had a provision to track the time variation of the abundances of a set of selected species. The primary science goal of MENCA was the in-situ measurement of composition of neutral species in the Martian exosphere, and to examine its spatial and temporal and variation. The observation from MENCA are vital in understanding the escape of the Martian atmosphere.
Youthsat: Radio Beacon for Ionospheric Tomography (RaBIT)
A unique dataset leading to ionospheric tomograms representing altitude-latitude variation of electron density over the 77oE meridian over the Indian region has been generated through RaBIT around specific times (~10:30 AM/PM). These tomograms have provided, among others: (a) First ever images of the ionospheric nighttime ESF irregularities (b) Quantification of the topside F3 ionospheric layers using Tomography (c) Evidence of wavelike modulations in the overall low and equatorial ionospheric region using tomography.
Click Here
Youthsat: Limb Viewing Hyper Spectral Imager ( LiVHySI )
The LiVHySI (Limb Viewing Hyper Spectral Imager) has recorded hyper-spectral images of nighttime airglow emissions from terrestrial thermosphere and mesopause regions simultaneously over a wide range of longitudes across the globe. Analysis of the thermospheric O1D emission at 630.0 nm and Hydroxyl band (9-3) emissions has brought forth new results exhibiting (a) simultaneous brightening in the thermospheric and mesospheric airglow emissions only during certain passes and (b) significant meridional intensity gradient in thermospheric airglow, possibly indicating neutral heating in the night sector.
A glimpse of payloads developed at SAC is here PDF - 564 KB