Disturbed and Quiet Time Ionosphere-thermosphere System at High Altitudes (DISHA), is a planned experiment to study the upper atmosphere, which is the first entity that feels the perturbation caused to Earth by solar events and how space weather concerns earthlings.  There are proposals for two small satellites with high and low inclinations named which aim to study the effects in the Ionosphere-Thermosphere system during space weather events and normal conditions of the Sun. The proposed DISHA mission will yield critical information on the structures in plasma and neutrals that adversely affect communication and navigation during space weather events. This will eventually help in a better description of the influence of space weather on space-based technological systems and sub-systems.

The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual-frequency synthetic aperture radar on an Earth observation satellite. The satellite will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing, to observe and understand natural processes on Earth. For example, its left-facing instruments will study the Antarctic cryosphere.

The NASA-ISRO Synthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth's land and ice masses 4 to 6 times a month at resolutions of 5 to 10 meters. It is designed to observe and measure some of the planet's most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides. 

NASA will provide the mission's L-band synthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific data GPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide the satellite bus, an S-band synthetic aperture radar (SAR), the launch vehicle, and associated launch services.

All data from NISAR would be freely available 1 to 2 days after observation and within hours in case of emergencies like natural disasters. Data collected from NISAR will reveal information about the evolution and state of Earth's crust, help scientists better understand our planet's natural processes and changing climate, and aid future resource and hazard management.

XPoSat (X-ray Polarimeter Satellite) is a small satellite mission of the Indian Space Research Organisation dedicated for study of polarisation of cosmic X-ray sources. The X-ray polarisation measurements will be carried out with a Thomson scattering X-ray polarimeter instrument POLIX and simultaneous timing and spectroscopic measurements will be carried out with a co-aligned semiconductor based X-ray detectors system XSPECT. Energy bands of the two X-ray instruments are 8-30 keV for POLIX and 0.8-15.0 keV for XSEPCT. The polarisation measurements will be performed using anisotropic Thomson scattering of polarised X-rays and this will be enabled by spinning the satellite around the viewing axis of POLIX during the source observations. Being a dedicated X-ray polarisation mission in this unexplored energy band, XPoSat is poised to give us glimpses of a new frontier in high energy astrophysics and also allow many in-depth investigations of astrophysical processes in neutron stars and black hole sources.

Aditya-L1 is a satellite dedicated to the comprehensive study of the Sun. It has 7 distinct payloads developed, all developed indigenously. Five by ISRO and two by Indian academic institutes in collaboration with ISRO.

Aditya in Sanskrit means the Sun. L1 here refers to Lagrange Point 1 of the Sun-Earth system. For common understanding, L1 is a location in space where the gravitational forces of two celestial bodies, such as the Sun and Earth, are in equilibrium. This allows an object placed there to remain relatively stable with respect to both celestial bodies.

The strategic placement at the L1 Lagrange point ensures that Aditya-L1 can maintain a constant, uninterrupted view of the Sun. This location also allows the satellite to access solar radiation and magnetic storms before they are influenced by Earth's magnetic field and atmosphere. Additionally, the L1 point’s gravitational stability minimizes the need for frequent orbital maintenance efforts, optimizing the satellite's operational efficiency.

Aditya-L1 will stay approximately 1.5 million km away from Earth, directed towards the Sun, which is about 1% of the Earth-Sun distance. The Sun is a giant sphere of gas and Aditya-L1 would study the outer atmosphere of the Sun. Aditya-L1 will neither land on the Sun nor approach the Sun any closer.

Chandrayaan-3 is a follow-on mission to Chandrayaan-2 to demonstrate end-to-end capability in safe landing and roving on the lunar surface. It consists of Lander and Rover configuration. It will be launched by LVM3 from SDSC SHAR, Sriharikota. The propulsion module will carry the lander and rover configuration till 100 km lunar orbit. The propulsion module has Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to study the spectral and Polari metric measurements of Earth from the lunar orbit.

• Lander payloads: Chandra’s Surface Thermophysical Experiment (ChaSTE) to measure the thermal conductivity and temperature; Instrument for Lunar Seismic Activity (ILSA) for measuring the seismicity around the landing site; Langmuir Probe (LP) to estimate the plasma density and its variations. A passive Laser Retroreflector Array from NASA is accommodated for lunar laser ranging studies.

• Rover payloads: Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS) for deriving the elemental composition in the vicinity of landing site.

GSLV-F12/NVS-01 mission is accomplished successfully on Monday, May 29, 2023. This Geosynchronous Satellite Launch Vehicle (GSLV) mission deployed NVS-01 navigation satellite, weighing about 2232 kg, into a Geosynchronous Transfer Orbit. The vehicle lifted off at 10:42 hours IST from the second launch pad at SDSC-SHAR, Sriharikota and injected the satellite after about 19 minutes of flight.

NVS-01 is the first of the second-generation satellites envisaged for the Navigation with Indian Constellation (NavIC) services. NVS series of satellites will sustain and augment the NavIC with enhanced features. This series incorporates L1 band signals additionally to widen the services. For the first time, an indigenous atomic clock will be flown in NVS-01.

The Thybolt Mission uses Dhruva Space's P-DoT Satellite Platform for conducting a sequence of technology demonstrations, as well as to enable advancements in research, constellation development and application agnostics use by customers. The Thybolt-1 and Thybolt-2 satellites are made on the Dhruva Space-developed P-DoT system. This is a 0.5U Spacecraft bus that includes a communication payload to enable rapid technology demonstration and constellation development for multiple users. It also demonstrates Store-and-Forward functionality for authorised users in the amateur frequency band.

This compact, scalable platform leverages a powerful processor and Space-grade components that enables high agility as well as reliable and robust operations. The payload used on the satellite is a novel Store-and-Forward payload receiving messages from sensor nodes or remote Ground Stations; it also stores the aforementioned messages on-boardflash memory for downlinking them at a network connected ground station.

The mission was used to demonstrate store-and-forward (S&F) operations and perform scheduled and unscheduled uplink of S&F data from amateur operators, store the data onboard and transmit the same data to distributed amateur radio compatible ground station/s in India and publish wherever required as per the Experiment Outline for Amateurs.he upcoming Indian Space Policy has been envisioned to allow launch of private satellites. In India, the amateur community has a dearth of reliable satellite platforms to build, launch and perform experiments.

The Anand nanosatellite is a technology demonstrator to demonstrate the capabilities and commercial applications of miniaturized earth-observation camera for earth observation using a microsatellite in Low Earth Orbit. This is a three-axis stabilised satellite consisting of a satbus, accommodating all subsystems like telemetry, tele-command, electrical power system, Attitude Determination and Control System (ADCS), on-board computers and others and a payload unit.

Chandrayaan-2 mission is a highly complex mission, which represents a significant technological leap compared to the previous missions of ISRO. It comprised an Orbiter, Lander and Rover to explore the unexplored South Pole of the Moon. The mission is designed to expand the lunar scientific knowledge through detailed study of topography, seismography, mineral identification and distribution, surface chemical composition, thermo-physical characteristics of top soil and composition of the tenuous lunar atmosphere, leading to a new understanding of the origin and evolution of the Moon.

After the injection of Chandrayaan-2, a series of maneuvers were carried out to raise its orbit and on August 14, 2019, following Trans Lunar Insertion (TLI) maneuver, the spacecraft escaped from orbiting the earth and followed a path that took it to the vicinity of the Moon. On August 20, 2019, Chandrayaan-2 was successfully inserted into lunar orbit. While orbiting the moon in a 100 km lunar polar orbit, on September 02, 2019, Vikram Lander was separated from the Orbiter in preparation for landing. Subsequently, two de-orbit maneuvers were performed on Vikram Lander so as to change its orbit and begin circling the moon in a 100 km x 35 km orbit. Vikram Lander descent was as planned and normal performance was observed upto an altitude of 2.1 km. Subsequently communication from lander to the ground stations was lost.

The Orbiter placed in its intended orbit around the Moon will enrich our understanding of the moon’s evolution and mapping of the minerals and water molecules in Polar regions, using its eight state-of-the-art scientific instruments. The Orbiter camera is the highest resolution camera (0.3 m) in any lunar mission so far and will provide high resolution images which will be immensely useful to the global scientific community. The precise launch and mission management has ensured a long life of almost seven years instead of the planned one year.

EMISAT is a satellite built around ISRO’s Mini Satellite-2 bus weighing about 436 kg. The satellite was successfully placed in its intended sun-synchronous polar orbit of 748 km height by PSLV-C45 on April 01, 2019. The satellite is intended for electromagnetic spectrum measurement.

Microsat-R, an imaging satellite was successfully injected into intended orbit of 274 km by PSLV-C44 on January 24, 2019

HysIS, the primary satellite of PSLV-C43 mission, weighing about 380 kg, is an earth observation satellite configured around ISRO’s Mini Satellite-2 (IMS-2) bus. The primary goal of HysIS is to study the earth’s surface in the visible, near infrared and shortwave infrared regions of the electromagnetic spectrum.

PSLV-C40 carries a Microsatellite (Microsat) built by ISRO as a co-passenger payload. Microsat is a small satellite in the 100 kg class that derives its heritage from IMS-1 bus. This is a technology demonstrator and the fore runner for future satellites of this series. The satellite bus is modular in design and can be fabricated and tested independently of payload.

Overall Size:

• 304 x 246 x 510 mm3 (stowed)

• 304 x 670 x 510 mm3 (deployed)

Payloads:

Earth Exosphere Lyman Alpha Analyser (EELA) payload from Laboratory for Electro-Optics Systems (LEOS), Bengaluru Registers terrestrial exospheric line-of-sight neutral atomic hydrogen Lyman Alpha flux. Besides, it will estimate the interplanetary hydrogen Lyman-alpha background flux by means of deep space observations.

Origami Camera payload from SAC is a Remote Sensing Colour camera with a novel lens assembly for optical realisation in a small package. There is scope for its future scalability and utilisation in regular satellites.

Overall Size:

• 304 x 246 x 364.3 mm3 (stowed)

• 304 x 670 x 364.3 mm3 (deployed)

Payloads:

Surface Bidirectional Reflectance Distribution Function Radiometer (SBR) payload from Space Applications Centre (SAC), Ahmedabad measures the BRDF (Bidirectional Reflectance Distribution Function) of the Earth surface and will take readings of the reflectance of different surface features due to Sun albedo.

Single Event Upset Monitor (SEUM) payload from SAC monitors Single Event Upsets occurring due to high energy radiation in the space environment.

SCATSAT-1 is a continuity mission for Oceansat-2 Scatterometer to provide wind vector data products for weather forecasting, cyclone detection and tracking services to the users. The satellite carries Ku-band Scatterometer similar to the one flown onboard Oceansat-2. The spacecraft is built around standard IMS-2 Bus and the mass of the spacecraft is 371 kg. The spacecraft will be put in SSP orbit of 720 km altitude with an inclination of 98.1 deg by PSLV-C35. The mission life of the satellite is 5 years.

The SCATSAT-1 was launched by PSLV-C35 on Monday morning at 9:12 hrs (IST) on September 26, 2016 from the First Launch Pad of SDSC SHAR, Sriharikota.

AstroSat is India’s first dedicated Space Astronomy Observatory launched into a 650-km, 6° inclination orbit on September 28, 2015, with a lift-off mass of 1515 kg, by PSLV-C30 (XL) rocket from Satish Dhawan Space Centre Sriharikota. AstroSat carries a total of five scientific payloads enabling imaging, studying temporal and spectral properties of galactic and extra- galactic cosmic sources in a wide range of wavelengths on a common platform.

The unique feature of this observatory is its capability for carrying out broad band simultaneous multi-wavelength observation going from far ultra violet to gamma rays. UVIT has the highest angular resolution of 1.5 arc sec which is 3 times better than the next best UV telescope (GALEX-Galaxy evolution explorer) operational today. LAXPC has the highest collecting area in comparison to any other X-ray detector till today. CZTI possesses a unique capability of measuring X-ray polarization and also acts as an open detector beyond 100 keV.

ISRO enabled Indian academic institutions Tata Institute of Fundamental Research (TIFR) Mumbai, Indian Institute of Astrophysics (IIA) Bangalore, Inter University Centre for Astronomy &Astrophysics (IUCAA) Pune and Physical research laboratory (PRL) Ahmedabad

IRNSS-1A is the first satellite in the Indian Regional Navigation Satellite System (IRNSS). It is one of the seven satellites constituting the IRNSS space segment.

Payloads - IRNSS-1A carries two types of payloads navigation payload and ranging payload. The navigation payload of IRNSS-1A transmits navigation service signals to the users. This payload is operating in L5-band and S-band. A highly accurate Rubidium atomic clock is part of the navigation payload of the satellite. The ranging payload of IRNSS-1A consists of a C-band transponder which facilitates accurate determination of the range of the satellite. IRNSS-1A also carries Corner Cube Retro Reflectors for laser ranging.

The Satellite with ARGOS and ALTIKA (SARAL) is a joint Indo-French satellite mission for oceanographic studies. SARAL performs altimetric measurements designed to study ocean circulation and sea surface elevation.

The payloads of SARAL are:

• Ka band Altimeter, ALTIKA- built by the French National Space Agency CNES. The payload is intended for oceanographic applications, operates at 35.75 Giga Hertz.

• ARGOS Data Collection System- built by the French National Space Agency CNES. ARGOS contributes to the development and operational implementation of the global ARGOS Data Collection System. It will collect a variety of data from ocean buoys to transmit the same to the ARGOS Ground Segment for subsequent processing and distribution.

• Solid State C-band Transponder (SCBT) is from ISRO and intended for ground RADAR calibration. It is a continuation of such support provided by C-Band Transponders flown in the earlier IRS-P3 and IRS-P5 missions.

The payloads of SARAL are accommodated in the Indian Mini Satellite-2 bus, which is built by ISRO.

Radar Satellite-1 (RISAT-1) is a state-of-the-art Microwave Remote Sensing Satellite carrying a Synthetic Aperture Radar (SAR) Payload operating in C-band (5.35 GHz), which enables imaging of the surface features during both day and night under all weather conditions.

Active Microwave Remote Sensing provides cloud penetration and day-night imaging capability. These unique characteristics of C-band (5.35GHz) Synthetic Aperture Radar enable applications in agriculture, particularly paddy monitoring in kharif season and management of natural disasters like floods and cyclones.

Megha-Tropiques is an Indo-French Joint Satellite Mission for studying the water cycle and energy exchanges in the tropics. The main objective of this mission is to understand the life cycle of convective systems that influence the tropical weather and climate and their role in associated energy and moisture budget of the atmosphere in tropical regions.

Megha-Tropiques provides scientific data on the contribution of the water cycle to the tropical atmosphere, with information on condensed water in clouds, water vapour in the atmosphere, precipitation, and evaporation. With its circular orbit inclined 20 deg to the equator, the Megha-Tropiques is a unique satellite for climate research that should also aid scientists seeking to refine prediction models.

Chandrayaan-1, India's first mission to Moon, was launched successfully on October 22, 2008 from SDSC SHAR, Sriharikota. The spacecraft was orbiting around the Moon at a height of 100 km from the lunar surface for chemical, mineralogical and photo-geologic mapping of the Moon. The spacecraft carried 11 scientific instruments built in India, USA, UK, Germany, Sweden and Bulgaria.

After the successful completion of all the major mission objectives, the orbit has been raised to 200 km during May 2009. The satellite made more than 3400 orbits around the moon and the mission was concluded when the communication with the spacecraft was lost on August 29, 2009.

IMS-1, previously referred to as TWSat (Third World Satellite), is a low-cost microsatellite imaging mission of ISRO (Indian Space Research Organization).

CARTOSAT–1 is the first Indian Remote Sensing Satellite capable of providing in-orbit stereo images. The images were used for Cartographic applications meeting the global requirements. Cameras of this satellite have a resolution of 2.5m (can distinguish a small car).

The Cartosat–1 provided stereo pairs required for generating Digital Elevation Models, Ortho Image products, and Value added products for various applications of Geographical Information System (GIS).

HAMSAT is a Micro-satellite for providing satellite based Amateur Radio services to the national as well as the international community of Amateur Radio Operators (HAM). It consists of two transponders-one indigenously developed by Indian Amateurs, with the expertise of ISRO and the experience of HAMSAT-INDIA. The second transponder has been developed by a Dutch Amateur Radio Operator and Graduate Engineering student at Higher Technical Institute, Venlo, The Netherlands.

GSAT-3, known as EDUSAT is meant for distant class room education from school level to higher education. This was the first dedicated "Educational Satellite" that provide the country with satellite based two way communication to class room for delivering educational materials.

This is a Geo-synchronous satellite developed on I-2K bus. GSAT-3 was co-located with METSAT(KALPANA-1) and INSAT-3C at 74o E longitude.

METSAT (renamed as Kalpana - 1 on February 5, 2003 after the Indian born American Astronaut Dr. Kalpana Chawla, who died on February 1, 2003 in the US Space Shuttle Columbia disaster) is the first in the series of exclusive meteorological satellites built by ISRO.

It provides the first set to transponders for Swaran Jayanti Vidya Vikas Antariksh Upagraha Yojana (Vidya Vahini) for interactive training and developmental communication giving fillip to the training and developmental Communication channel of INSAT.

The Technology Experiment Satellite (TES), weighing 1108 kg, was launched on October 22, 2001. TES is an experimental satellite to demonstrate and validate the technologies like attitude and orbit control system, high-torque reaction wheels, new reaction control system, light-weight spacecraft structure, solid state recorder, X-band phased array antenna, improved satellite positioning system, miniaturised TTC and power systems and, two-mirror-on-axis camera optics.

TES also carried a panchromatic camera for remote sensing experiments.

GSAT-1 carrying three C-band transponders and one S-band transponder was launched on April 18, 2001 by GSLV-D1. GSAT-1 is used for conducting communication experiments like digital audio broadcast, internet services and compressed digital TV transmission. Several new spacecraft elements like improved reaction control thrusters, fast recovery star sensors and heat pipe radiator panels were also tested on this satellite.

IRS-P4 (OCEANSAT) is the first satellite primarily built for Ocean applications, weighing 1050 kg placed in a Polar Sun Synchronous orbit of 720 km, launched by PSLV-C2 from SHAR Centre, Sriharikota on May 26, 1999.

This satellite carries Ocean Colour Monitor (OCM) and a Multi - frequency Scanning Microwave Radiometer (MSMR) for oceanographic studies. IRS-P4 thus vastly augment the IRS satellite system of ISRO comprising four satellites, IRS-1B, IRS-1C, IRS-P3 and IRS-1D and extend remote sensing applications to several newer areas.

Mission completed on August 8, 2010 after serving for 11 years and 2 months.

First satellite successfully orbited by ASLV

IRS-1A, the first of the series of indigenous state-of-art remote sensing satellites, was successfully launched into a polar sun-synchronous orbit on March 17, 1988 from the Soviet Cosmodrome at Baikonur. IRS-1A carries two cameras, LISS-I and LISS-II with resolutions of 73 metres and 36.25 metres respectively with a swath width of about 140 km during each pass over the country.

Mission completed during July 1996 after serving for 8 years and 4 months.

When INSAT-1B was launched on 30 August 1983, it almost suffered the same fate as the INSAT-1A. It was not until mid-September that Ford and Indian controllers succeeded in deploying its solar array. By then it had been stationed at 74°E in place of INSAT-1A. Full operational capability was achieved in October 1983. It continued to operate into 1990 with all its 4375 two-way voice or equivalent circuits in use. Around 36,000 earth images were returned.

Bhaskara II, was launched on November 20, 1981 from Kapustin Yar onboard the Inter¬cosmos launch vehicle. The main objectives of Bhaskara-II, similar to Bhaskara-I, were to conduct earth observation experiments for applications related to hydrology, forestry, and geology using the two band television camera system operating in the 0.54 to 0.66 microns visible band and 0.75 to 0.85 micron near infra red band and to conduct ocean-surface studies using Satellite Microwave Radiometer (SAMIR) operating at 19.35, 22.235 & 31.4 GHz frequency band

Successful operation during mission life. Despite the problem faced by one of the two onboard cameras, sent more than two thousand images which were used for many studies.

The Ariane Passenger Payload Experiment (APPLE) was ISRO's first indigenous, experimental communication satellite. It was launched into GTO (Geosynchronous Transfer Orbit) (Geosynchronous Transfer Orbit) by the third development flight of ESA'a Ariane vehicle from Kourou on June 19, 1981. It was boosted into Geo-synchronous Orbit (GEO) by apogee motor of ISRO, derived from fourth stage motor of SLV-3. It was designed and built in just two years with limited infrastructure in industrial sheds. It gave ISRO valuable hands on experience in designing and developing three-axis stabilized geostationary communication satellites as well as in orbit raising manoeuvres, in orbit deployment of appendages, station keeping, etc.

APPLE was used for nearly two years to carry out extensive experiments on time, frequency and code division multiple access systems, radio networking computer interconnect, random access and pockets switching experiments.

RS-D1 was a 38 kg experimental spin stabilized satellite designed with a power handling capability of 16W. It was launched onboard SLV-3 from SHAR Centre on May 31, 1981. The launch was a partial success as the satellite did not reach the intended height and thus it stayed in orbit for only 9 days. The satellite carried a solid-state camera using linear array of detectors for remote sensing applications.

RS-1 was a 35 kg experimental spin stabilized satellite designed with a power handling capability of 16W. It was successfully launched onboard SLV-3 from SHAR Centre on July 18, 1980 into an orbit of 305 x 919 km with an inclination of 44.7°. All the fourth stage parameters of SLV-3 were successfully telemetered to the ground stations by RS-1 during the launch phase. The satellite had an orbital life of 9 months. The satellite carried Digital sun sensor, Magnetometer and temperature sensors. The structure was made of Aluminium Alloy.

The First Experimental Remote Sensing Satellite built in India. The onboard TV camera imageries were used in the field of Hydrology and Forestry. Rich scientific data sent by SAMIR was used for oceanographic studies.

The Aryabhata spacecraft, named after the famous Indian astronomer, was India's first satellite; it was completely designed and fabricated in India and launched by a Soviet Kosmos-3M rocket from Kapustin Yar on April 19, 1975.