Indian Space Program: News & Discussion

[Amber G.]

ISRO Chairman Dr V. Narayanan inaugurates research centre at IIT Madras
ISRO Chairman Dr V. Narayanan inaugurated a new research centre at IIT Madras to advance space technology. The centre will support 'Atmanirbhar Bharat' initiatives, promoting self-reliance in advanced space technologies, and will attract global talent and research funding.

[drnayar]

Spadex dedocking successful.

https://x.com/isro/status/1900100280345321521

Awesome!
My take on why it's impressive:

- ISRO has demonstrated its capability to bring two satellites together in orbit and then separate them, a complex task requiring high precision and control.

- The SDX-1 and SDX-2 satellites were able to perform the docking and undocking maneuvers autonomously, without real-time human intervention.

- The development of SDX-1 and SDX-2 has pushed the boundaries of Indian spacecraft design and propulsion systems.

i think the more awesome part is they are small satellites, takes more skill and expertise to dock/undock

As a side note the tech can be used for robotic "inspector" satellites that can repair satellites in orbit or "take care" of enemy satellites

[SSridhar]

ISRO Chairman Dr. V. Narayanan launches Research Centre at IIT Madras - PIB Release

The new Centre will serve as a nodal center for research in heat transfer, cooling systems, and fluid dynamics, which are essential for the next generation of spacecraft and satellite technologies Dr. V. Narayanan, Chairman, Indian Space Research Organisation (ISRO) launched a new research centre at the Indian Institute of Technology Madras (IIT Madras) today (17th March 2025).

The ‘Shri S. Ramakrishnan Centre of Excellence in Fluid and Thermal Science Research’ will Support ‘Atmanirbhar Bharat’ Initiatives, promoting self-reliance in advanced space technologies and attract Global Talent and Research Funding. This will position India as a leader in thermal sciences research for space applications.

This state-of-the-art research facility, housed at the Department of Mechanical Engineering, will focus on critical advancements in spacecraft and launch vehicle thermal management—a key area for India's expanding space ambitions.

Shri S Ramakrishnan was a distinguished alumnus of IIT Madras. He was a distinguished aerospace engineer with accomplishments in the arena of launch vehicle engineering and development. He was also the project director for PSLV and GSLV MK3. He also served as the Director of LPSC and VSSC. The Nation honoured him with Padma Shri during 2003 for his contributions in the areas of science and engineering.

Also during the occasion, the ‘Arcot Ramachandran Seminar Hall’ was also inaugurated by Prof. V. Kamakoti, Director, IIT Madras, in the presence of Dr. V. Narayanan, Chairman, ISRO. Prof. Arcot Ramachandran (1923 - 2018), a world-renowned Professor of Heat Transfer, was the Director of IIT Madras between 1967 and 1973. He was instrumental in establishing the Heat Transfer and Thermal Power lab at IIT Madras

The centre will serve as a nodal centre for research in heat transfer, cooling systems and fluid dynamics. These are essential for the next generation of spacecraft and satellite technologies. Scientists and engineers from ISRO will work alongside faculty and researchers from IIT Madras to address complex thermal challenges in space applications.

This initiative is a game-changer for India's space program as thermal control is vital to satellite longevity, spacecraft safety, and mission success. The research at this Centre of Excellence (CoE) will directly impact upcoming lunar, Mars, and deep-space missions, ensuring India remains at the forefront of space technology.

Dr. V. Narayanan, Chairman, ISRO inaugurated this lab in the presence of Prof. V. Kamakoti, Director, IIT Madras, Dr. S. Somanath, Dr. Vikram Sarabhai Professor, ISRO, Centre Coordinator Prof. Arvind Pattamatta, Department of Mechanical Engineering, IIT Madras, Prof. P. Chandramouli, Head, Department of Mechanical Engineering, IIT Madras, Dr. P.V. Venkitakrishnan, Professor of Practice, Department of Mechanical Engineering, IIT Madras, faculty, researchers and students.

Speaking on the occasion, Dr. V. Narayanan, Chairman, ISRO, said, “The Cryogenic Engine technology was denied to India but today, we have three different such engines with the third one being human-rated. Only six countries in the world have this technology. We have made three world records in this technology - We got it right in our third attempt. Second, From the engine test to flight, we got it done in 28 months. Other countries took between 42 Months and 18 Years. and finally, we conducted the test in 34 Days which no other country had done as they took around 5 to 6 months.”

Further, Dr. V. Narayanan added, “I thank all the people who contributed towards this effort. I am sure under Prof V Kamakoti’s leadership; the Institute will do great work. The Institute should aim for a couple of Nobel Prizes. The Department of space will support IIT Madras completely in all these efforts”

Recalling his association with Shri S Ramakrishnan, Dr. V. Narayanan said, “Shri S Ramakrishna was not just a technocrat but was a great Manager.”

Looking forward to the collaboration, Prof. V. Kamakoti, Director, IIT Madras, said, “More and more we explore the space, we have an increasing need for technologies that could handle thermal and cooling requirements. I am sure the proposed Centre jointly with ISRO shall develop very effective solutions for the same.”

The Key Roles of the Centre will include:

Spacecraft and Launch Vehicle Thermal Management: Addressing heat dissipation challenges in satellites and launch vehicles.
Experimental & Numerical Studies on Cooling Systems: Developing efficient cooling solutions using micro heat pipes, spray cooling, vapor chambers, and two-phase heat transfer devices.
High-Fidelity Simulation & Testing Facilities: Utilizing cutting-edge computational fluid dynamics (CFD) simulations and experimental setups for real-world validation
Capacity Building & Training: Encouraging ISRO scientists to pursue advanced degrees at IIT Madras while fostering industry-academia collaborations.

Highlighting the expected outcomes from this new research centre, its coordinator Prof. Arvind Pattamatta, Department of Mechanical Engineering, IIT Madras, said, “In the Medium Term (Next 3-5 Years), we are hoping to achieve breakthroughs in Advanced Thermal Management such as development of new active and passive cooling techniques for spacecraft electronics and prototyping and Testing of Next-Gen Heat Pipes, which are Innovative cooling systems for long-duration space missions. Further integration with ISRO’s Space Missions and incorporation of new research findings into upcoming ISRO satellite and launch vehicle projects will also be a focus area.”

Dr. S. Somanath, Dr. Vikram Sarabhai Professor, ISRO, Prof. P. Chandramouli, Head, Department of Mechanical Engineering, IIT Madras, and Dr. P.V. Venkitakrishnan, Professor of Practice, Department of Mechanical Engineering, IIT Madras, also spoke on the occasion.

Expected outcomes in the Long-Term (Beyond 5 Years):

Revolutionizing Spacecraft Design: Laying the groundwork for high-performance, reusable space vehicles with superior thermal control.
Enhancing India’s Deep Space Exploration Capabilities: Supporting future missions such as Gaganyaan, lunar and interplanetary missions.
Boosting Indigenous Space Technology: Reducing reliance on foreign technology by developing cutting-edge thermal management solutions within India

***

[Amber G.]

^^^Thanks SSridhar... (I also posted about this just a few posts above your post..)
About the passing of Shri S Ramakrishnan, he was a renowned aerospace engineer who played a crucial role in India's space program . He was instrumental in the development of the Polar Satellite Launch Vehicle (PSLV) and served as the Director of the Liquid Propulsion Systems Centre (LPSC) and the Vikram Sarabhai Space Centre (VSSC) .

His contributions to India's space program are significant, and his legacy will be remembered for generations to come. Ramakrishnan was awarded the Padma Shri in 2003..

[SSridhar]

I have had the good fortune of knowing Shri. Ramakrishnan. Was a gem of a person.

[Ashokk]

ISRO & SCL develops 32-bit Microprocessors for space applications

On March 5, 2025, the first production lots of the 32-bit microprocessors developed for space applications, VIKRAM3201 & KALPANA3201, were handed over to Dr. V. Narayanan, Secretary, DOS /Chairman, ISRO by Shri S. Krishnan, Secretary, MeitY, in a function organised at New Delhi by the Semiconductor Laboratory (SCL), Chandigarh. These microprocessors were designed & developed by the Vikram Sarabhai Space Centre of ISRO in collaboration with SCL, Chandigarh. Dr. Unnikrishnan Nair, Director, Vikram Sarabhai Space Centre, also participated in the function along with the design teams. Dr. Kamaljeet Singh, Director-General of SCL/MeitY and his team provided a brief overview of the activities undertaken for the realization, packaging & qualification of these processors for launch vehicle applications.



VIKRAM3201 is the first fully “Make-in-India” 32-bit microprocessor that is qualified for use in the harsh environmental conditions of launch vehicles. The processor was fabricated at the 180nm CMOS semiconductor fab of SCL. This processor is an advanced version of the indigenously designed 16-bit VIKRAM1601 microprocessor which has been flying in the Avionics system of ISRO’s launch vehicles since 2009. A “Make-in-India” version of the VIKRAM1601 processor was subsequently inducted in 2016 after the 180nm semiconductor fab was established at SCL, Chandigarh.

VIKRAM3201 & the VIKRAM1601 has a custom Instruction Set Architecture, with floating-point computation capability and high-level language support for the Ada language. All the software tools such as the Ada compiler, assembler, linker, simulator along with Integrated Development Environment (IDE) are developed in-house by ISRO. A C language compiler is also under development for providing more flexibility to users in other domains. This is the first of its kind in India and has enabled Atmanirbharata in the area of high reliability microprocessors and onboard computers for navigation, guidance & control of launch vehicles. The initial lot of VIKRAM3201 devices was successfully validated in space in the Mission Management Computer of the PSLV Orbital Experimental Module (POEM-4) in the PSLV-C60 mission.



KALPANA3201 is a 32-bit SPARC V8 RISC microprocessor and is based on the IEEE 1754 Instruction Set Architecture. The microprocessor has been designed to be compatible with open-source software toolsets along with in-house developed simulator & IDE and has been tested with flight software.
ISRO & SCL develops 32-bit Microprocessors for space applications

Four other devices that were jointly developed with SCL were also handed over towards significant miniaturisation of the launch vehicle Avionics system. This includes two versions of a Reconfigurable Data Acquisition System (RDAS) integrating multiple indigenously designed 24-bit Sigma-Delta Analog to Digital Converters on a single chip along with a Relay driver Integrated Circuit & a Multi-Channel Low Drop-out Regulator Integrated Circuit for high reliability applications.

[Amber G.]

I have had the good fortune of knowing Shri. Ramakrishnan. Was a gem of a person.

Thanks for posting this. Yes, as you say he was gem of a person for anyone who knew him. He worked on the design and development of the vehicle's control and guidance systems and his expertise in control systems and guidance algorithms played a crucial role in the success of the PSLV.

[SSridhar]

Quite early on, he was involved with the design & fabrication of LAMs.

[SSridhar]

Isro attempts & succeeds in 'rolling' SpaDeX satellites, learning key for future docking - ToI

[SSridhar]

Panel pulls up space department for shelving fibre project

Nearly 20 years after the Vikram Sarabhai Space Centre (VSSC) signed an agreement with the National Aerospace Laboratories (NAL) to develop T800 - a high-strength carbon fibre for space launch vehicles - a parliamentary committee has criticised the failed and abandoned project.

The Public Accounts Committee (PAC) noted the shift in policy on critical raw materials, from focusing on indigenous development due to embargo concerns in 2006, to abandoning the project in 2019 after ISRO was removed from the restricted list. The PAC has called on the Department of Space to reassess India's requirements for strategic materials and formulate policies to ensure the indigenous development of critical materials and technologies.

The T800 Quest

Initiated in February 2006, the project aimed to develop a "special grade carbon fibre" through a MoU between CSIR's NAL and VSSC. Initially due in September 2007, the project faced multiple delays, with extensions granted until 2015 due to procurement and technical issues. NAL, despite working on T300-grade carbon fibre, struggled to achieve the T800 grade, producing only 80% of the target strength. To reach the required T800 grade, another ₹7 cr would have been needed to improve facilities. However, the Joint Review Committee opted to terminate the MoU in 2019, after ₹4 cr had been spent.

The PAC criticised VSSC for poor planning, noting NAL's insufficient capabilities when the MoU was signed and questioning why repeated extensions were granted. The committee also flagged the "waste of ₹4 cr" and the loss of 13 years without tangible results. It emphasised the lack of proper exit strategies and recovery clauses in the MoU, which further prolonged the project.

Geopolitics and T800

In 2005, ISRO was on the restricted list, prompting the need for indigenous development. By 2019, with ISRO removed from the list, global suppliers were identified, reducing supply risks. However, the PAC warned of ongoing risks from embargoes or supply disruptions. The committee also questioned the rationale of "money saved is money produced" in the case of strategic materials, urging the Department of Space to reassess India's long-term strategic material needs and develop domestic production.

The ministry also highlighted that, due to the dual-use nature of T800, export clearance issues could still persist, especially considering the changing geopolitical landscape.

For a change, the PAC is right on dot and is not questioning the 'wasteful expenditure'.

[csaurabh]

Panel pulls up space department for shelving fibre project

Nearly 20 years after the Vikram Sarabhai Space Centre (VSSC) signed an agreement with the National Aerospace Laboratories (NAL) to develop T800 - a high-strength carbon fibre for space launch vehicles - a parliamentary committee has criticised the failed and abandoned project.

The Public Accounts Committee (PAC) noted the shift in policy on critical raw materials, from focusing on indigenous development due to embargo concerns in 2006, to abandoning the project in 2019 after ISRO was removed from the restricted list. The PAC has called on the Department of Space to reassess India's requirements for strategic materials and formulate policies to ensure the indigenous development of critical materials and technologies.

The T800 Quest

Initiated in February 2006, the project aimed to develop a "special grade carbon fibre" through a MoU between CSIR's NAL and VSSC. Initially due in September 2007, the project faced multiple delays, with extensions granted until 2015 due to procurement and technical issues. NAL, despite working on T300-grade carbon fibre, struggled to achieve the T800 grade, producing only 80% of the target strength. To reach the required T800 grade, another ₹7 cr would have been needed to improve facilities. However, the Joint Review Committee opted to terminate the MoU in 2019, after ₹4 cr had been spent.

The PAC criticised VSSC for poor planning, noting NAL's insufficient capabilities when the MoU was signed and questioning why repeated extensions were granted. The committee also flagged the "waste of ₹4 cr" and the loss of 13 years without tangible results. It emphasised the lack of proper exit strategies and recovery clauses in the MoU, which further prolonged the project.

Geopolitics and T800

In 2005, ISRO was on the restricted list, prompting the need for indigenous development. By 2019, with ISRO removed from the list, global suppliers were identified, reducing supply risks. However, the PAC warned of ongoing risks from embargoes or supply disruptions. The committee also questioned the rationale of "money saved is money produced" in the case of strategic materials, urging the Department of Space to reassess India's long-term strategic material needs and develop domestic production.

The ministry also highlighted that, due to the dual-use nature of T800, export clearance issues could still persist, especially considering the changing geopolitical landscape.

For a change, the PAC is right on dot and is not questioning the 'wasteful expenditure'.

I am constantly bamboozled by these references to T300, T800 etc.
This report says that India will develop T100 ( which I take to mean T1000 ) carbon fibre

https://economictimes.indiatimes.com/in ... 978486.cms

For reference, T300, T800 and T1000 are not 'grades' of carbon fibre. They are simply names given by Toray corporation for their specific carbon fibre products. Different manufacturers such as Mitsubishi, Formosa, etc. have different brand names and numbers.

Toray also makes pitch based carbon fibres - M55J, M60J etc. which are also used by ISRO in good quantities and actually makes more sense to indigenize considering the fact that they are much harder to get in India than T300/T700 .

Also, if one government department is paying another government department, how exactly is the money 'wasted' ? And 7 cr is a tiny price to indigenize carbon fibre.

Mind spins at the nonsense being presented..
Btw NAL is still diligently working on carbon fibre production - last year a big tender came out for ordering all the equipments and furnaces. So that is public news.

[Ashokk]

ISRO successfully completes 1000hrs Life Test of Stationary Plasma Thruster for Spacecraft Electric Propulsion System

On March 27, 2025, ISRO successfully completed the life test of 1000hrs on the 300mN Stationary Plasma Thruster, that is developed for induction into the Electric Propulsion System of satellites.The Electric Propulsion Systemis proposed to replace the chemical propulsion system in future satellites of ISRO and pave the way for communication satellites which use only electric propulsion systems for orbit raising and station keeping.

The induction of these thrusters will result in extensive mass savings thereby enabling the enhancement of transponder capacity in communication satellites. These thrusters use Xenon as the propellant. The Specific Impulse of the Electric Propulsion System, which is a major performance indicator of a space propulsion system, is at least 6 times that of the conventional propulsion system. The life test was carried out under the full power level of 5.4kW in a chamber that simulates the vacuum conditions of spaceand the erosion of the electrode liners was periodically monitored.

The erosion data measured during the life test is essential for predicting the subsequent erosion and hence the life of the thruster. This will be an important input for the satellite orbit management.This test is a major milestone to demonstrate the reliability and robustness of the thrusters before induction into the satellites. The Electric propulsion System is proposed to be inducted and validated in the upcoming Technology Demonstration Satellite (TDS-01) of ISRO and will be used for orbit raising to the Geostationary orbit.

[Ashokk]

ISRO achieves major breakthrough in Semicryogenic Engine development

ISRO is achieving progress in the design &development of a Semicryogenic engine or Liquid Oxygen / Kerosene enginewith a high thrust of 2000 kNthat will power the Semicryogenic booster stage of the LVM3 launch vehicle. The first major breakthrough in the Semicryogenic engine development programme was achieved on March 28, 2025, when the first successful hot test of Engine Power Head Test Article (PHTA),was carried out at ISRO Propulsion Complex, Mahendragiri, Tamil Nadu.

The Liquid Propulsion Systems Centre (LPSC) of ISRO is developing the Semi cryogenic propulsion Engine and Stage. The stage (SC120) powered by the 2000kN semi-cryogenic engine (SE2000) will replace the present core liquid stage (L110) of LVM3 for payload enhancement and power the booster stages of future launch vehicles. Non toxic and non hazardous propellants (Liquid Oxygen and Kerosene) are employed in Semi cryogenic propulsion and this will deliver higher performance compared to existing L110 stage. Induction of Semi cryogenic propulsion system along with uprated cryogenic stage in the LVM3 vehicle enhances its payload capability from 4 tonne to 5 tonne in GTO.

Major subsystems of SE-2000 engine include thrust chamber, pre-burner, turbo pump system, control components and start up system. The SE2000 engine works with a complex oxidizer rich staged combustion cycle with high chamber pressure of 180 bar (with propellant feed system delivering pressures up to 600 bar) & specific impulse of 335s. The complex engine hardware uses special materials to withstand the high temperature and oxidiser rich combustion. The hardware along with the space grade kerosene are realised in partnership with Indian industry. The development of this engine in these high thrust levels is highly challenging and this technology is available with only very few nations.

The realization of a test facility to qualify the engine and stage is equally complex and challenging. The complex Semicryogenic Integrated Engine Test facility (SIET) was established at ISRO Propulsion Research Complex (IPRC), Mahendragiri for testing the engine and stage and was dedicated to the nation by the Honourable Prime Minister, Shri Narendra Modi, on February 27, 2024. This facility caters to storage and servicing of large volume of propellants and service fluids at high pressures. The capability of the test stand is validated through several flow and ignition trials. The test stand which involves many sophisticated control components are managed from a Test Control Centre that is also developed indigenously. This facility with a state-of-art PLC-based control system and data acquisition system is capable of testing semi-cryogenic engines up to 2600 kN thrust.

Prior to the conduct of integrated engine level hot tests, it is planned to carry out performance evaluation tests of the intermediate configuration, designated as Power Head Test Article (PHTA),that comprises all the engine systems except the thrust chamber. The hot test that was carried out today, is the first of a series of tests planned to validate the design of the propellant feed system, including the low-pressure and high-pressure turbo-pumps, the pre-burner, start system and control components. All subsystems for the test were realized and had undergone rigorous qualification test prior to integration to Power Head Test Article.

The Ignition sequence for PHTA was derived from a series of hot tests in single element level. In order to ensure the smooth ignition process during the PHTA test, another test article, Pre-burner Ignition Test Article (PITA), was realized, whichconsists of the pre-burner along with its feed systems, start-systems, and related control components. A series of tests were successfully completed using the PITA and the optimum start sequence for power head test article was derived.

Today’s test demonstrated the smooth ignition and boost strap mode operation of engine over a test duration of 2.5 seconds. The objective of the test was to validate the integrated performance of the critical subsystems such as the pre-burner, turbo pumps, start system and control components by carrying out a hot-firing for a short-duration of 2.5 seconds. The test proceeded as predicted and all the engine parameters were as expected.

With this breakthrough, ISRO is further planning a series of tests on the PHTA to further validate and finetune the performance before the realization of the fully integrated engine.

[Amber G.]

New Item: ndian astronaut Group Captain Shubhanshu Shukla to fly to International Space Station in May 2025

He will become the first Indian astronaut to go to the ISS, and the first Indian to go to space in the last 40 years

[Cyrano]

Nice ! What will he ride on? Russki rocket or Muski rocket?

[Ashokk]

ISRO Successfully qualifies fourth stage engine of PSLV with Stellite Nozzle Divergent

The liquid engines being flown in the fourth stage of PSLV (PS4) use nozzle divergent made up of imported Columbium (C103) material. An alternate material, Stellite (KC20WN), was proposed for the nozzle divergent realization to achieve Atmanirbharatha along with associated cost savings. Stellite is a cobalt based alloy with additions of Chromium, Nickel, Tungsten and Iron. It is a material which retains good strength at high temperatures up to 1150°C and hence becomes a suitable material for high temperature applications. As part of the qualification programme, 3 hot tests were already completed on two hardware in the first phase. On April 08, 2025, the final test of the qualification programme was successfully completed through a hot test for a long duration of 665 seconds at the test facility in ISRO Propulsion Complex, Mahendragiri. The use of this alloy has resulted in cost savings to the extent of 90%.

[Ashokk]

SPADEX Mission: Successful demonstration of Second Docking and Power Transfer

ISRO successfully demonstrated the docking of the SPADEX satellites (SDX 01 & SDX 02) for the second time on April 20, 2025 at 08:20 PM.Subsequently, power transfer from SDX 02 to SDX 01 satellite as well as vice versa was also exercised and accomplished on 21st April, 2025. The experiment involved operating a heater element in one of the satellites through power from the other satellite.The duration of power transfer was approximately 4 minutes and the performance of the satellites was as expected.

In the second docking attempt, the docking was completed with full autonomy from an inter-satellite distance of 15m till docking, whereas in the first docking attempt, an additional hold point was manually exercised at an inter-satellite distance of 3m.

The second docking experiment was preceded by detailed ground simulations and on-orbit trials incorporating the experience gained from first docking & undocking experiments, thereby providing immense confidence for the second docking demonstration.

The demonstration of the fully autonomous second docking along with power transfer marks the completion of an important milestone in the SPADEX mission.

[SSridhar]

Excellent news. They have incorporated lessons learnt from the first docking.

[sanjaykumar]

When done, they should use that space arm as a space hammer to disable the other satellite, the most vulnerable part would probably be the antenna.

As a trial artisat system of course.

[Amber G.]

Om Shanti. We mourn the passing of Padma Vibhushan Dr. K. Kasturirangan — a visionary leader who shaped India’s space and education landscape with wisdom, dedication, and humility. As the former head of ISRO, he guided India’s space programme to global acclaim, pioneering landmark satellite missions and championing innovation.

His contributions transcended science — they helped define a modern, forward-looking India. We honor his legacy and extend our deepest condolences.

[ernest]

Om Shanti

[SSridhar]

Om Shanti.

Besides his tremendous achievements in space, he also drafted the plan for the preservation of the Western ghats as well as the New Education Policy (NEP).

[SSridhar]

Who is Tejpaul Bhatia? Indian-origin executive takes over as Axiom Space CEO ahead of historic Indian astronaut mission - ToI

Bhatia, formerly the Chief Revenue Officer of the Houston-headquartered firm, joins at a time of great importance. Group Captain Shubhanshu Shukla, chosen by the Indian Space Research Organisation (ISRO) and NASA, will fly to the International Space Station next month on Axiom's Ax-4 mission, a collaboration that sees India enter a new era for human spaceflight.

[Ashokk]

ISRO successfully conducted a short duration hot test of Semicryogenic Engine

A short duration hot test of the Semicryogenic Engine was successfully conducted at the test facility in ISRO Propulsion Complex (IPRC), Mahendragiri on April 24, 2025. This ignition test is the second milestone after the successful first hot test on March 28 ,2025, that was a major breakthrough in the testing of the Semicryogenic engine test programme.

In this test, the Engine Power Head Test Article, encompassing all engine systems except the thrust chamber, was subjected to a hot test for a duration of 3.5 seconds, that validated the engine start-up sequence. During the test, the engine was successfully ignited and operated up to 60% of its rated power level, demonstrating stable and controlled performance.

These tests are part of a planned series of evaluations designed to validate the design integrity and performance of critical subsystems, including the low-pressure and high-pressure turbo pumps, pre-burner and associated control systems. The results provided crucial data to finalize the operational sequencing of the full Semicryogenic engine.

Further qualification tests are scheduled to comprehensively validate the engine system, ultimately paving the way for its induction into ISRO's launch vehicles.

[Ashokk]

India successfully conducts 'dogfight' in Space between Chaser and Target satellites

India is currently executing a unique and highly advanced "dogfight" in space, involving a "chaser" and a "target" satellite positioned approximately 500 kilometers above the Earth. This follows similar exercises conducted by Chinese defense satellites in low Earth orbits in 2024.

"Dogfighting" in space involves coordinated, close-range maneuvers between spacecraft, akin to aerial dogfights between fighter jets.

The Indian endeavor represents an additional element of the ambitious SPADEX Mission by the Indian Space Research Organization (ISRO), a mission that seamlessly integrates numerous societal and strategic goals.

Two Indian satellites, traveling at 28,800 kilometers per hour—28 times faster than a commercial passenger jet and 10 times the speed of a bullet—are autonomously engaged in a precise flight pattern orchestrated by ISRO. Both satellites have been executing rendezvous and proximity maneuvers.

This current "dogfight" follows an earlier, manually-controlled circumambulation or parikrama between the chaser and target satellites, which took place a few weeks prior.

During an interview with NDTV, ISRO Chairman Dr V Narayanan said, In the SPADEX mission, India has already "successfully demonstrated docking and undocking twice over."

After these extended docking and undocking maneuvers, the ISRO chief reported that 50% of the fuel remained on the two satellites.

The ISRO chief also noted that precise rocket launch and efficient orbital management have left the satellites with nearly 2.5 kilograms of fuel each, which will extend the mission's lifespan.

[Ashokk]

Isro Lines Up Major Space Missions from May to July 2025

Among the major launches, Isro will lift off the PSLV-C61 rocket on May 18, carrying the EOS-09 Earth observation satellite. Originally slated for May 19, the launch has been advanced by a day.
EOS-09, equipped with C-band synthetic aperture radar, is designed to capture high-resolution images of Earth's surface regardless of weather or time of day, enhancing India's surveillance and disaster management capabilities.

Leading the line-up is the scheduled spaceflight of Group Capt. Shubhanshu Shukla of the Indian Air Force to the International Space Station (ISS) on May 29, 2025, as part of Axiom Space's Ax-4 mission.

Another key mission is Test Vehicle-D2 (TV-D2), a critical component of the Gaganyaan programme. It will simulate an abort scenario to demonstrate the Crew Escape System and test various components including sea recovery operations, control systems, thermal protection, parachutes, and a scaled-down life support system, which are all essential for future human spaceflight.

In June, Isro will join hands with Nasa to launch the Nisar satellite aboard GSLV-F16. NISAR, a Low Earth Orbit (LEO) observatory jointly developed by Nasa and Isro, will map the entire globe every 12 days using dual-frequency radar (Nasa's L-band and Isro's S-band). The mission aims to study Earth's ecosystems, ice sheets, sea level rise, and natural hazards like earthquakes and landslides.

Looking ahead to July, the LVM3-M5 mission will support a commercial contract with AST SpaceMobile Inc., USA, launching BlueBird Block-2 satellites under NewSpace India Limited (NSIL).

[SSridhar]

India delays 1st Gaganyaan astronaut launch to 2027 - Space.com

India now plans to launch astronauts to space no sooner than 2027, shifting the goal post for the country's first human spaceflight yet again.

Indian space minister Jitendra Singh announced the latest delay during a press conference Tuesday (May 6), running through the progress of India's crewed spaceflight program and providing an updated timeline for its first Gaganyaan crewed missions.

The Indian Space Research Organisation (ISRO) is now targeting the first quarter of 2027 for its first astronaut launch, which was originally planned to fly in 2022. The landmark human spaceflight will be preceded by a trio of uncrewed launches to further qualify the rocket and ground infrastructure.

"We have to accomplish three uncrewed missions before targeting the actual crewed mission because there is life involved," Singh said.

The first of those three long-delayed uncrewed Gaganyaan missions, known as G1, is slated to launch in the fourth quarter of this year, and will carry a half-humanoid robot named Vyomitra (Sanskrit for "space friend") to collect data in flight.

The second and third Gaganyaan missions, G2 and G3, will also carry Vyomitra, and will launch in 2026. The first crewed mission, dubbed H1, will fly in the first quarter of 2027.

India's astronauts, or Gaganyatris, for the H1 and H2 missions were selected in Februrary 2024. They are Prasanth Balakrishnan Nair, Ajit Krishnan, Angad Pratap and Shubhanshu Shukla, all of whom served as test pilots in the Indian air force.

[Amber G.]

Operation Sindoor: Domestic strategic space assets, foreign commercial satellites used by armed forces

ENGALURU: Indian armed forces used a wide range of space assets - domestic and international commercial - to carry out Operation Sindoor, multiple sources have confirmed to TOI.
“All of our strategic assets were put to use in different ways by our armed forces for Operation Sindoor. Our teams have been working round the clock and we are proud that Isro could help our forces in missions important for the country,” a senior official from Isro told TOI.
Another official said that aside from domestic assets directly available with the armed forces (India has 9-11 military satellites), Isro also facilitated “repeatable” data from a commercial global operator. “While data from our satellites from the Cartosat series and others were also used for planning, images were procured from Maxar,” the senior official said.
Maxar, the US-based satellite imagery provider supplies images to multiple governments and non-government entities across the world, while it remains unclear if Pakistan used its services for any of its operations during the current conflict. It is noteworthy that Pakistan also has access to the extensive military space assets of China.

Indian armed forces also have access to other satellite data from Sentinel from Europe and another commercial operator from the US.
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Indian assets

“Indian satellites provide periodic data - with downloads of specific areas possible about once in 14 days. This data was made use of, while they used commercial data that’s available once a day too,” the official said.
The Cartosat family of satellites, with high-resolution imagery and dual-use (image & video) capabilities, has been a key asset in India’s military intelligence toolkit. Launched for the first time in 2005, and progressively upgraded with satellites like the Cartosat-2C (for military), these satellites have provided crucial imagery for operations.

Cartosat-2C, for example, delivers images with a resolution of 0.65 metres- an improvement over previous models- and has been vital in reconnaissance and surveillance operations. The high-resolution images from Cartosat can capture areas of interest (AOI) with incredible clarity, enabling commanders to make precise decisions based on intelligence from space. These were used for the 2016 Surgical Strike.

Aside from Cartosat, the Risat family of satellites would have provided radar images useful to track movement, while the Gsat family of satellites were used for communications. “In all, a variety of Indian space assets have been useful and efforts are on to increase support to the armed forces in the years to come,” the official said. India’s NavIC combined with other global GPS systems also aided in operations.

Future build-up:

Indian Space Association (ISpA) director-general Lt Gen (retd) AK Bhat, said: “There would have been extensive use of space assets for imagery, sat-com (satellite communication) and PNT (positioning, navigation and timing). Space technology is an integral part of modern warfare.”


Isro chairman V Narayanan, who said Sunday that 10 satellites are working round the clock for the armed forces, did not specifically comment on Operation Sindoor. He, however, told TOI: “We will be launching another important satellite on May 18, the EOS-09 or Risat-1B, which will add teeth to our armed forces.”

“The satellite features an advanced C-band synthetic aperture radar system that delivers high-resolution Earth surface imagery in all weather conditions. This capability significantly enhances India’s surveillance capabilities,” he added. Unlike conventional optical satellites limited by cloud cover or darkness, Risat-1B’s radar technology penetrates these obstacles effectively.


Earlier this month, Narayanan had said that India would launch 100-150 satellites in the next five years. Among these would be the 52 satellites part of the Space-Based Surveillance-3 (SBS-3) programme. Thirty-one of these will be developed by the private sector.

[uddu]

https://x.com/MeghUpdates/status/1923002678365274153
@MeghUpdates
BREAKING NEWS

India's 101st rocket will be launched into space this Sunday, confirms ISRO.

ISRO is set to LAUNCH India's most advanced RADAR imaging 'spy' satellite, EOS-09 (PSLV-C61), on 18th May.

[rahulm]

ISRO launches are nowdays taken for granted on BR

Doesnt look good.There appears to be a malfunction. From my reading of the altitude v time plot, the altitude veered off suddenly from the planned and thats when the live coveage switched away from the plot to a mundane table to a more usual than mundane rime filler commentary.

Mission failed. Something happend after 3rd stage ignition. 1st and 2nd stage performed nominally. Eventually Mission Director amde an apperance and gave the shortest and tersest announcement < 15 seconds and walked off.ISRO had had failures in the past but this time it seemded like an immediate blackout on info and coverage.

[A_Gupta]

The third stage failed.

[SSridhar]

Yes, unfortunately. But, display showed also that the 4th stage ignited.Will it have enough power to take it to the desired orbit?

[Amber G.]

"Upto 2nd stage, performance was normal. 3rd stage ignited. During 3rd stage functioning, we had an observation... EOS-09 mission could not be accomplished" says #ISRO Chief Dr. V. Narayanan

[rahulm]

For those interested, go to 35m:23s in the live stream vdo, the deviation can be clearly seen @

• Time = 373.8 sec
  Range = 873.3 km
  Rel velocity = 5.63 km/s
  Alt=342.0 km and
  Azimuth = 174.2 deg

Actually the deviation starts a bit before 35m:23s but i let it run a few seconds so the deviation trace is obvious.

From the brochure - PS3 was supposed to separate at 493 seconds at 443.8 kms altitide and 5.830 kms rel vel so it failed approx 493 - 373.8 = approx 119.2 seconds before targeted time, approx 101.8 kms below target altitude and 0.2 km/s below target rel. velocity.

Just a reminder, EOS-09 was a SAR bird. This PSLV version has an excellent track record and we sure needed its reliability this time. Oh well. PIck up the pieces and go again.

ISRO Tweets: Today 101st launch was attempted, PSLV-C61 performance was normal till 2nd stage. Due to an observation in 3rd stage, the mission could not be accomplished.

To me the use of the word "Observation" is new and curious. Previously, ISRO has used "anomaly" and "malfunction".

[SSridhar]

I won't rule out any possibility. Pretty sure that ISRO has enough Space Situational Awareness to rule out deliberate interference.

[rahulm]

Vishnu Som tweets:

Fall in chamber pressure in the 3rd stage of @isro 's PSLV rocket results in mission failure. First two stages worked normally. The PSLV C-61 was carrying the EOS-09 reconnaissance satellite, crucial for day and night time observation of our boundaries. ISRO Chief says they will be back soon.

[Prem Kumar]

A much-touted radar imaging satellite, right after Op Sindoor, failing during a PSLV launch raises a few suspicions

On a different note, ISRO has been cruising along for quite some time. Instead of 50+ recon satellites that keeps getting talked about, they have hardly launched anything in the last year or two

They need a kick up their rear-end. Enough of this "we are civilians onlee" bullshit. If they cant do the job, outsource it to private sector players

They are chasing vanity projects like Gaganyaan, Shukrayaan etc, while natsec is languishing

[Amber G.]

Yeah, it’s frustrating when a key satellite fails—especially after something like Op Sindoor. But let’s not forget ISRO has quietly played a big role in supporting national security. A lot of what they do for defense ops—like providing real-time imagery, secure comms, and surveillance—isn’t publicized, but it’s critical.

As for fewer launches lately—true, but a lot of current satellites like Cartosat, RISAT, and EMISAT are still working and feeding data to agencies like DRDO and NTRO. Plus, longer satellite lifespans mean fewer frequent launches.

Private players are already getting into the game—Pixxel, Skyroot, Agnikul—thanks to ISRO opening up through IN-SPACe and NSIL. That’s a big shift.

And projects like Gaganyaan and Shukrayaan aren’t just for show—they build serious tech that can spill over into defense, like re-entry tech and human-rated systems.

ISRO doesn't need a kick—they need more backing, faster clearances, and better funding. They’ve delivered a lot with limited resources. Let’s build on that instead of writing them off.

[gakakkad]

These are complex projects . These things happen . Can't think of one space agency or launch company that doesn't have a failure every now and then . They'll figure it out . I am not worried .

Doubt it's sabotage etc . We haven't had a failure for a while so were used to succeeding every launch . But that is not the norm anywhere in the world .

[S_Madhukar]

I wonder if it’s time to have a proper Space command and have it deal with such launches. I am having dreams of those USAF Delta rocket launches… Civilians style work leads to too many security holes and process gaps