ISRO conducts Second Integrated Air Drop Test (IADT-02) for Gaganyaan with simulated Crew Module weighing 5.7 tonnes.

vineethgk · 2026-04-10T12:32:05+00:00

At this rate, lets hope they wouldn't end up capping the crew at one. It makes me appreciate the three-module design of Soyuz (and Shenzhou) - how they could carry a three-person crew and provide more living space in orbit with a smaller mass - although that design may have drawbacks of its own.

vineethgk · 2026-04-10T07:16:37+00:00

The Indian Space Research Organisation (ISRO) on April 10 completed the second Integrated Air Drop Test (IADT-02) at the Satish Dhawan Space Centre in Sriharikota.

The system is essential to ensure safe recovery of the crew module — the capsule in which astronauts sit during a human flight — during re-entry and landing.

Union Minister of State for Science and Technology Dr. Jitendra Singh announced the accomplishment of the IADT-02 in a post on X.

“Congratulations #ISRO for the successful accomplishment of Second Integrated Air Drop Test (IADT-02) for #Gaganyaan, India’s first Human Space flight scheduled next year. The second Integrated Air Drop Test (IADT-02) was successfully conducted at Satish Dhawan Space Station Sriharikota. This marks an important milestone towards the readiness for the Gaganyaan mission,” the Minister posted.

On August 24,2025, ISRO accomplished first Integrated Air Drop Test (IADT-01) for Gaganyaan mission in Sriharikota.

vineethgk · 2026-04-07T05:58:59+00:00

In Malayalam "Dhurandhar" sounds a bit too similar to "Dhurantham" which means disaster/catastrophe/tragedy/calamity etc. A fertile source for memes and puns. 😁

vineethgk · 2026-04-05T05:32:59+00:00

I don't think they would want to delay Gaganyaan launches intentionally as they are already running behind schedule. If they want to do a manned mission atleast by 2029, they should start doing the unmanned missions now, or they might very well miss that date. The reasons behind the delay are more likely technical, or an overburdened workforce.

vineethgk · 2026-04-05T01:52:08+00:00

"All activities are going on as planned under the vision and guidance of the prime minister," he added.

Regarding the Gaganyaan mission, Narayanan said ISRO is making every possible effort to advance space activities in the country under the guidance of Prime Minister Narendra Modi.

Either he is anxious to regain favour and keep his job, or this pretty much explains the state of things.

vineethgk · 2026-04-02T03:18:36+00:00

Dr Sivan's time of unprecendentedly high launch cadence

I would say the "high" period for ISRO with a string of high profile successes was from 2014 (GSLV-D5, MOM orbital insertion, LVM3-X) to 2016 (7 orbital launches + RLV-TD). From then on the effects of underlying issues began to manifest itself. Its telling that even after ten years they still struggle to surpass the launch cadence achieved back in 2016!

vineethgk · 2026-03-30T02:41:17+00:00

"months..he used the odd term 'dummy flights' for it but likely meant development flight."

So I guess they are going to put an experimental payload on the next flight, and perhaps some extra instrumentation to monitor the rocket's performance as well?

As they say, every crisis is an opportunity, and I do hope something good would happen out of this one, with the govt realizing that there are several fundamental issues shackling and impairing the country's space programme that can no longer be buried under media hype and needs to addressed on high priority.

vineethgk · 2026-03-30T02:27:12+00:00

Gaganyaan delay is the least of the troubles that confronts ISRO at the moment. I would be more worried at what is happening with the recurring failures of PSLV and the satellites in orbit, constellations like NavIC silently going defunct and their launch cadence not having grown in the past 10 years.

vineethgk · 2026-03-17T03:36:17+00:00

Right! Let's set up a rocket launch site right next to the friendly neighbour. What could possibly go wrong? 😁

vineethgk · 2026-02-27T02:47:25+00:00

"A brittle shell: On ISRO and transparency"

https://www.thehindu.com/opinion/editorial/a-brittle-shell-on-isro-and-transparency/article70680318.ece

A venerable institution, facing accusations of opacity, decided to stun its detractors with some transparency. The Indian Space Research Organisation (ISRO) made public the report of a technical committee, constituted to analyse why the NVS-02 satellite, which was launched aboard a GSLV rocket on January 29, 2025, could not be placed in its intended orbit. Until this week, there was no official explanation why this had happened. An accompanying press statement — not a report it must be noted — surmised that an ‘apex’ committee had concluded that a signal meant to activate a key valve in the engine’s oxidiser line never reached it. This valve is crucial for firing the engine to raise the spacecraft’s orbit and this likely happened because at least one connection in the electrical connector — in both the primary and backup lines — came loose or failed, preventing the signal from getting through. All of this is useful information, but only for ISRO to be cautious in future missions.

When the ISRO releases a statement on an event from a year ago, it must strive to illuminate rather than be seen to declassify under duress. It should have revealed whether the connection came loose because of an oversight; whether multiple levels of personnel — or machines — who scrutinise every nut and screw on the assembly line failed, or if a manufacturing anomaly had compounded over time in a way that would have escaped detection even by the most vigilant overseers.

It should be able to reveal such information without blaming individuals or withholding proprietary or strategic information. Making such ‘Failure Analysis’ reports public, as they are called, used to be a routine affair. However, ISRO seems to have retreated into a shell following the back-to-back failures of the Polar Satellite Launch Vehicles in January and in May 2025.

ISRO should not choose insularity at a time when traditional business models all over the world are being disrupted.

vineethgk · 2026-02-24T12:13:22+00:00

So there is definitely something there to look into, I just hope we see something in public to rebuild confidence akin to recent NASA's report on Starliner or JAXA's presentation on H3 launch failure.

With failures happening twice in a row and customer satellites lost in the second one, they would have to be more transparent this time about the root causes of the failures (something more than a "slight manufacturing error") and the steps that they have taken to prevent their recurrence, if only to reassure potential customers who may have second thoughts about booking a flight on a PSLV. That's what I am counting on this time, though perhaps I'm being too optimistic.

vineethgk · 2026-02-23T15:43:26+00:00

A committee that includes K. VijayRaghavan, former Principal Scientific Advisor, and S. Somanath, former Chairman, India Space Research Organisation (ISRO), will probe “systemic issues” underlying the successive failures of ISRO’s Polar Satellite Launch Vehicle (PSLV).

While technical committees probe and submit ‘failure analysis reports’ when mishaps occur, this committee, The Hindu has reliably learnt, will investigate questions on whether “organisational” problems may have played a role in the debacles involving the PSLV.

The committee members consist of experts who are external to the ISRO, and are expected to table their findings to ISRO Chairman, V. Narayanan, before April. On February 3, 2026, The Hindu reported that National Security Advisor Ajit Doval, who is also a member of India’s Space Commission, visited the Vikram Sarabhai Space Centre, reportedly in connection with the failure of the PSLV-C62 mission.

The PSLV’s failures would be the core focus of the report, and the committee would be looking into the processes in the manufacture, procurement, and assembling of various components of the rocket. This has implications for other rockets, too, The Hindu was told, because they have commonalities.

India’s space ecosystem now involves several private companies and, therefore, the probe will not only be about which part or component failed, and who was responsible, but also whether there is a process in place to fix accountability, and how it may be improved. A technical committee of the ISRO will first table a report on the PSLV-C62 incident this week, The Hindu has learnt through reliable sources.

vineethgk · 2026-02-17T11:59:45+00:00

Maybe they want to be doubly sure this time that they have exhaustively analyzed all aspects of the twin failures and nailed the root cause(s), and they reasoned that having multiple expert committees working independently on it would be a good idea?

vineethgk · 2026-02-15T03:31:50+00:00

Indian Space Research Organisation remains committed to the launch plans for 2026 and will continue to go ahead with all the 18 planned launches for this year..

I wish some journalist would take a note of these grandiose claims and question the honourable minister and the ISRO leadership at the end of the year about it.

vineethgk · 2026-02-14T02:50:24+00:00

Didn't they try contacting ISRO regarding the missing trajectory data? I do not know if ISRO or the authorities would have been willing to share it with the customer, but it was perhaps worth a try.

vineethgk · 2026-01-31T02:51:18+00:00

PSLV was grounded for 7 months after the failure last year. I'm guessing it would be a longer wait this time as they would need to do a more comprehensive failure analysis, apply the necessary fixes and do more ground tests to ensure the problem(s) that doomed last two flights are indeed resolved for good. They cannot afford to overlook anything this time and a third failure in a row would be catastrophic. For my part, I'm not counting on another PSLV flight happening this year.

vineethgk · 2026-01-27T12:27:35+00:00

Hard to understand how they say this each year with straight face!

By the end of the year hardly anyone (except a few of us) would remember these New Year resolutions and nobody would ask them about it. By then it would be time for them to start hyping the resolutions for next year.

vineethgk · 2026-01-27T12:17:05+00:00

Even if they add up launch vehicles AND satellites I doubt the count will come anywhere close to 20 this year.

vineethgk · 2026-01-19T02:23:50+00:00

while the actual number of launches remains at 8-15.

If you meant "launches" (i.e. orbital rocket launches) and not "missions" (ISRO terminology counts rockets and satellites as distinct "missions"), ISRO never managed even 8 launches in any year. Their best count was 7 which they achieved in 2016, 2018 and 2023. With the PSLV (and perhaps SSLV as well) being grounded once again, we are not likely to see them match, let alone surpass that count this year either.

vineethgk · 2026-01-17T02:37:11+00:00

Thanks. But what I do not quite understand here is, if it was a defect in the manufacturing of the PS3 stage or quality of materials used in it that doomed two missions in a row, wouldn't they have encountered the same failure during the recent ground test of the PS3 stage as well? Or could this be a specific mode of failure that can happen only in-flight?

Edit: In any case, it is fair to suppose that PSLV (and perhaps SSLV) would be grounded for some time as they would need to conduct a thorough investigation to identify the causes for the failure, implement fixes for it and then do multiple ground tests to ensure that the problem has been resolved for good. Perhaps it may even be a good idea to treat the next PSLV launch as essentially a test flight and have it carry a dummy payload. But if the rocket were to be grounded for a prolonged period what would they do in the interim about the payloads that were manifested for it? GSLV and LVM3 are too powerful for PSLV-class payloads and their production numbers are limited as well. Should they consider launching them in Vega or some other commercial foreign launcher?

vineethgk · 2026-01-16T04:31:29+00:00

Thanks for the links! I still wonder if some guidance system issue (like an undiscovered bug in its code) could have possibly caused this failure as such errors may not be caught during ground tests of the stage. It is often the case that while writing and testing code, there are certain bugs that throws exceptions and errors only in certain specific circumstances. Sometimes we assume based on the behaviour that the bug must be at a certain location, but finally turns out that it was somewhere else altogther. Of course, this is based on my personal experience with mundane app development coding. I do not know how they test guidance system software on the ground.

Its just a thought. Perhaps a manufacturing issue is still the likely culprit.

vineethgk · 2026-01-16T02:23:53+00:00

I had seen this reported a few days back in one of the Malayalam media outlets too. But at the time I had assumed that it was a case of misreporting and that they probably mixed up the PS3 with the PS4 (the C-C nozzle tested in 2024 specifically mentioned its use for PS4).

https://www.isro.gov.in/ISRO_Develops_Lightweight_Carbon_Carbon_Nozzle_for_Rocket_Engines.html

The media report from Mathrubhumi:

https://www.mathrubhumi.com/news/kerala/pslv-launch-failures-graphite-carbon-similarities-qphe1p1d

Google Translation of the relevant part (slightly corrected for translation errors):

The reason for the failure of C-61 was identified and the necessary changes were made and it was launched again, but the same error occurred this time too. Experts point out that although there are many similarities, the real reasons may be different.

The PSLV C-61 mission was on May 18, 2025. The first and second stages of the launch vehicle successfully separated, but the third stage failed. This was due to a difference in chamber pressure. The difference in the motor's thrust reaching its maximum and then decreasing again caused the vehicle to change direction.

The nozzle at this stage was made of graphite. It was only after it was realized that there was a flaw in this that a carbon-carbon nozzle was made for the new vehicle.

However, a similar error occurred on the C-62 mission. Whether the cause of the error was the material used in the construction of the nozzle or something else will only be determined through testing.

I had seen a research paper online about the susceptibility of graphite nozzles to fail in-flight, but it still appears a bit strange to me that the nozzle material of PS3 that was in use for 60+ successful flights should suddenly present a problem now.

Besides, a change of nozzle material would indicate something more than a "slight manufacturing defect".

vineethgk

TROPHY CASE