Indian Space Program: News & Discussion

[Prem Kumar]

GISAT launch - problem in upper stage (cryo) ignition
NAVIC launch - valve in upper stage didn't open
RISAT launch - drop in pressure in upper stage

All 3 were mission-critical satellites for surveillance & targeting

Once is happenstance. Twice is coincidence. Three times is enemy action

[Amber G.]

Dr. S Somanath (@SomanathSpeak)

Dear Colleagues,

We encountered a setback today during the #PSLVC61 mission. Yet, true to its indomitable spirit,
@ISRO
will swiftly assemble its finest minds to dissect the anomaly and chart a meticulous course forward. I am aware of the formidable challenges we faced during the development of the third-stage solid motor -- an endeavour marked by multiple failures. It is indeed unusual to witness such anomalies resurfacing at this stage. Nevertheless, I have complete confidence that the team will identify the root cause both swiftly and effectively.

Over the years, such challanges have only strengthened our conviction that failure is never defeat, but rather a formidable tutor. Every towering success of ISRO has been forged in the crucible of adversity -- shaped by lessons deeply learnt and courageously applied.

Setbacks have ever served to refine our resolve and deepen our scientific rigour. Nothing shall deter our pursuit of knowledge, which we carry forward with characteristic poise and unwavering precision.

[Amber G.]

Totally get why people are raising eyebrows—three big missions with issues, all linked to surveillance. But let’s look at the full picture.

GISAT-1 (EOS-03) had a cryo stage issue—yes, a sensor failure, not sabotage. ISRO’s working on GISAT-2 with improvements.
IRNSS-1H (NAVIC) didn’t separate from the heat shield, but the rocket worked fine. And NAVIC as a system is fully operational, with upgrades on the way.
RISAT glitch was one PSLV launch, but the RISAT series overall has been a big success—2B and 2BR1 are up there, giving India crucial day-night, all-weather imaging.

Three issues, but not three failures. And remember: ISRO’s track record is still one of the best in the world, despite tight budgets and growing complexity.

As the saying goes:
"

क्षिप्रं विनश्यति दुर्विचारः

"

Let’s not rush to write off an agency that gave us Chandrayaan, Cartosat, NAVIC, RISAT, GSAT, and now Gaganyaan—all building both civil and defense strength.

Instead of suspicion, what ISRO needs is stronger support, quicker decision-making, and private sector scale-up. They’ve done more with less for decades.

[Prem Kumar]

Amber G - appreciate your spirited defense & also want to say that most here are core supporters of ISRO. But that being said, lets break this down into 2 topics

1) Is ISRO coasting?
2) Is there sabotage by the enemy?

Answer to (1) is an emphatic Yes

1) ISRO did 5 launches in 2024 & 2 in 2025 so far. Both in 2025 failed. China did 68 in 2024, SpaceX did 138!! With PSLV being the proven workhorse, I don't see any reason we are not having 1 launch per week
2) We are falling behind in the Heavy Launch capability, like many have mentioned. At this rate, SpaceX will eat our lunch both because of their high-frequency of launches & their cost/kilogram
3) Too much of "We are peaceful onlee" koolaid drinking. While the 11-12 ISRO satellites provided vital intel during Op Sindoor, what we need are 50+ birds up there. At the present launch rate, we will never get there. During Op Sindoor itself, we purchased commercial, high-res satellite imagery (incidentally better than ours, at 30 cm resolution) from Maxar. So did the Pakis
4) Too much focus on vanity projects like Shukrayaan & Gaganyaan. No one doubts their benefits for space exploration, igniting people's minds etc, but at the present anemic launch-rate, these are not our #1 priority

So, ISRO needs a fire up its ass, more funding & we need to de-risk our programs by having private players get into launches in a big way (with Govt funding, because our VC douchebags won't fund any deep-tech). ISRO will handhold them, transfer tech, have scientists & project managers deputed to startups etc

This also helps in perception-management. ISRO can be the reliable workhorse like NASA. While the startups are encouraged to fail-fast & learn

Answer to (2) is this: Very Likely

From the very beginning, our enemies have sought to cripple our space & nuclear programs. The assassinations of Homi Bhabha & Vikram Sarabhai are well known. Then we saw the news of how, over a couple of decades, dozens of our BARC scientists died under "mysterious circumstances". Specifically to IRNSS, we saw an abnormal # of failures in imported Rubidium clocks (which we can be 100% certain, was sabotage). So, repeated failures of our EOS/strategic payload launches must be investigated, even if the individual causes seem disparate. We only have to recall the sophistication of the Stuxnet worm - it was programmed to do its deed at random intervals, which made debugging incredibly hard & led the Iranian team go on wild-goose chases. "Up the Supply Chain" hacking cannot be ruled out either, which would mean that the machines that make the machines might be tampered with, to produce a component with an incorrect tolerance

[Amber G.]

Thanks for your thoughtful post — appreciate the passion and the historical context you bring in. Many of us here are long-time admirers and supporters of ISRO, and we all want to see it thrive and succeed in its mission. That said, I’d like to gently push back on some of the conspiracy elements, especially regarding Prof. Bhabha and Sarabhai.

I studied nuclear physics in India, and had the privilege of knowing Prof Bhabha and learning under some of the very physicists who worked with Bhabha — his colleagues, students, and the generation that followed him. Among them, there is zero serious belief that Bhabha's death was anything other than a tragic plane crash in the Alps. Yes, the timing was unfortunate, and yes, it left a huge void — but in the academic and scientific community, no credible evidence has ever emerged pointing to assassination. Same goes for Vikram Sarabhai — while it's tempting to draw patterns, sometimes the most straightforward explanations are just… what happened.

As for the broader issue of sabotage — absolutely, vigilance is essential. We do operate in a geopolitical environment where space and nuclear capabilities are strategic assets. Failures, especially in critical missions, must be investigated thoroughly. But we also need to be careful not to conflate unrelated anomalies or lean too heavily on narratives that can distract from technical root causes. Stuxnet was real, yes — but that level of sophistication isn’t a catch-all explanation.

Let’s stay sharp, but also grounded. ISRO’s strength lies in transparency, rigor, and learning from failure — not in fear.

[Prem Kumar]

Good points

Last from me on this, so as to not derail the thread. Regarding Homi Bhabha, an ex-CIA operative went on record stating that they had assassinated him by taking down the plane. We can dismiss this as someone seeking publicity, but I find it hard to do so

In general, Indians tend to be lackadaisical about security & naive about how deep/long-term are the games played by our enemies. In fact, our history of being colonized came about because we didn't understand civilizational enemies, inimical ideologies & the depth of their motivation. So, a bit of paranoia does help, IMO

[Suraj]

Without taking a position as to what might be likely reasons for ISRO's problems and solutions, I want to mention that listing a set of failed missions and ascribing reasons for it is fundamentally incomplete reasoning.

What were the established causes of failure ? I assume ISRO has a published report on each ? To what extent were each of those missions substantially different ? The sensationalist aspect it easy to obtain from many sources. A detailed analysis would be real value add here.

Jumping to second order considerations - e.g. conspiracies - without first establishing baseline first order information and establishing the lack of any scientifically reasonable pattern, doesn't really help.

[drnayar]

GISAT launch - problem in upper stage (cryo) ignition
NAVIC launch - valve in upper stage didn't open
RISAT launch - drop in pressure in upper stage

All 3 were mission-critical satellites for surveillance & targeting

Once is happenstance. Twice is coincidence. Three times is enemy action

i think ISRO would need to have separate groups for core competencies., look at the number of people involved in each mission !! .. best to get whetted and do security clearances for those who work in such programs ... not sure it exists as it is

[Amber G.]

Some comments regarding what I consider conspiracy theories type issues that has been raised raised a few times here is BRF.

This is. my take, but is consistent with reputable sources. It gives background and useful information. Hope it is useful.

- Homi Jehangir Bhabha

Official account:

Bhabha died in a plane crash on January 24, 1966, when Air India Flight 101 (a Boeing 707 named Kanchenjunga) crashed into Mont Blanc in the Alps.

He was en route to Vienna to attend a meeting of the International Atomic Energy Agency (IAEA).

The crash killed all 117 people on board.

Conspiracy theories:

The most cited claim is that CIA was behind the crash to cripple India's nuclear program.

This idea gained traction in the mid-2000s after reports surfaced quoting a former CIA operative, Robert Crowley, in a controversial book "Conversations with the Crow" (by Gregory Douglas), allegedly saying the CIA sabotaged Bhabha's plane.

No solid evidence has ever surfaced to back this — no official inquiry, declassified documents, or corroboration from credible sources.

Reality (check):

Aviation investigators attributed the crash to pilot error — a miscalculation in altitude during approach in poor weather.

As said, Indian scientists - including Bhabha’s peers, have overwhelmingly considered it a tragic accident, not foul play.

Vikram Sarabhai

Official account:

Sarabhai died in his sleep of a heart attack on December 30, 1971, while at a guest house in Thumba, Kerala .
He was just 52 and under tremendous stress, managing both ISRO and the Atomic Energy Commission after Bhabha’s death.

Conspiracy theories:

Some speculate that his death was too sudden, at a crucial time when India’s space and nuclear programs were gaining momentum, including the 1974 Smiling Buddha test (which Sarabhai laid groundwork for).

Reality check:

Sarabhai had known health issues, including heart-related concerns.
No medical or forensic evidence has ever suggested foul play.

Related Theories: BARC Scientist Deaths

A series of deaths of BARCscientists over the 2000s, many under "mysterious" circumstances (suicides, drowning, etc.), have sparked speculation about foreign espionage.

While some deaths remain unexplained, India’s Ministry of Home Affairs has mostly ruled them as non-suspicious, citing personal issues or unrelated causes.

Again, no confirmed link to sabotage has been made public.

While it’s healthy to remain vigilant and curious, there is no credible or corroborated evidence that either Bhabha or Sarabhai was assassinated. Within the Indian scientific community, these ideas are considered conspiracy theories, not grounded in fact.

[Vayutuvan]

Article in OpIndia ca. 2019 also talks about deaths of BARC and ISRO scientists in this article. It also gives number of deaths under mysterious circumstances in the article.

https://www.opindia.com/2019/01/the-tra ... umstances/

Another data point is assassinations of five Iranian nuclear scientists on which there is a wikipedia page.

https://en.wikipedia.org/wiki/Assassina ... scientists

While these assassinations have been ascribed to Israel, specifically Mossad, they have neither taken the responsibility nor denied they did the deeds.

[Vayutuvan]

A 2020 article

https://thebulletin.org/premium/2020-11 ... n-targets/

says the following:

Since 2007, international media have reported the violent deaths of four scientists and engineers connected with Iran’s nuclear program and an attempt on the life of a fifth. The news reports on such killings are murky, incomplete, and, in some instances, likely inaccurate. The motivations and identity of the persons behind the killings are also obscure,1 but the fact that they are taking place is undeniable.
...
The Heisenberg uncertainty and beyond

Targeting atomic scientists to retard a potential nuclear weapons program predates the existence of nuclear weapons. Alarmed by the possibility that the giant of German physics, Werner Heisenberg, was working on an atomic bomb for Adolf Hitler, noted theoretical physicist Victor Weisskopf consulted with Hans Bethe, a renowned colleague working in the Manhattan Project, in the autumn of 1942; Weisskopf subsequently corresponded with Robert Oppenheimer, then newly appointed to lead theoretical work for the Manhattan Project. According to Thomas Powers’s account in Heisenberg’s War, Weisskopf wrote, “I believe that by far the best thing to do in this situation would be to organize a kidnapping of Heisenberg in Switzerland” (Weisskopf, 1942). Over time, within the Manhattan Project and the Office of Strategic Services (OSS), Weisskopf’s proposal mutated into a plot to kill Heisenberg—a plot that very nearly came to pass.

Because much, although still not everything, about the plot to assassinate Heisenberg is known, and because it is no longer politically sensitive, the case is worth delving into in some detail, as it adds clarity to more modern cases. One key element in the problem that confronted the Allies during World War II, however, was very different from later episodes: No one could doubt that Heisenberg would greatly advantage any Nazi effort to build an atomic bomb. Powers relates Oppenheimer’s view in 1944 that “the position of Heisenberg in German physics is essentially unique. If we were [undertaking a bomb project] in Germany, we should make desperate efforts to have Heisenberg as a collaborator” (Powers, 1993: viii). What the Allies could not know were Heisenberg’s intentions, and they famously remain a matter of debate, and even drama, today (Frayn, 1998).

American and British officials initially ignored the suggestion of Weisskopf and Bethe that Heisenberg be kidnapped (Powers, 1993). But the seed was planted—and it sprouted into kidnapping plans 15 months later (Powers, 1993).

Physicist Niels Bohr escaped from Nazi-controlled Denmark in September 1943, bearing what the New York Times described—in an early leak of nuclear weapons-related information— as “plans for a new invention involving atomic explosions…of the greatest importance to the Allied war effort” (New York Times, 1943). What Bohr carried was a rough sketch given to him by Heisenberg during their famous 1941 Copenhagen conversation;2 Bohr took the sketch to be of a weapon, but it was most likely a nuclear reactor. During a two-day rail journey in December 1943 from Chicago to Lamy, New Mexico, Bohr convinced Brig. Gen. Leslie Groves, then in charge of the overall Manhattan Project, that the drawing was evidence of a German bomb program. Despite Oppenheimer’s “formal assurance” that the sketch did not depict a viable weapon, Groves concluded that he must act to blunt the Nazi effort (Powers, 1993: 246–248).

Groves contacted the OSS—the swashbuckling US agency then responsible for intelligence and covert action—and by February 1944, Special Operations Branch officers were forming improbable kidnapping plans that included flying Heisenberg from an anticipated snatch in Switzerland, parachuting with him into the Mediterranean Sea, and rendezvousing in the water with a surfaced submarine. The inherent danger of such an operation shows that Heisenberg’s survival was not a high US priority; indeed, if capture by German authorities were imminent, the plan was to kill him (Powers, 1993). Nothing, however, could be done until he was located. Before he could be, these kidnapping schemes—but not the desire to neutralize Heisenberg as a threat—were put aside (Powers, 1993).

In November 1944, the OSS learned that Heisenberg planned to visit Switzerland the next month. Former major league baseball catcher and then OSS officer Moe Berg was dispatched to Zurich with orders that “Heisenberg must be rendered hors de combat” (out of action) if Heisenberg gave evidence that the German bomb effort was close to completion. Apparently Berg alone was to decide whether or not to kill Heisenberg (Powers, 1993: 391–392).

With a pistol in his pocket, Berg attended a lecture by Heisenberg, waiting for some sign of an advanced German atomic bomb program. Heisenberg offered no such signal and therefore survived. Instead, Berg reflected on his own “uncertainty principle” in regard to killing Heisenberg, a reference to the scientist’s most prominent contribution to the theory of quantum mechanics (Powers, 1993: 398–399).

Later that week, as the Battle of the Bulge turned to Allied advantage, Berg attended a dinner given for Heisenberg and heard him lament Germany’s coming loss of the war. This appeared to clinch the case that Heisenberg could not be part of a successful atomic bomb project and effectively ended any further US interest in killing him (Powers, 1993).

The end of World War II, however, did not mean that nation states were no longer interested in killing foreign scientists to address a perceived military threat. As Ian Black and Benny Morris reported in their 1992 book, Israel’s Secret Wars, under “Operation Damocles” in 1962, the Mossad assassinated Heinz Krug, the head of a German company involved in procurements related to Egypt’s missile-development efforts, and attempted to kill Hans Kleiwachter, an electronics expert with experience in Germany’s World War II V-2 rocket program (Black and Morris, 1992). On June 14, 1980, Yahia El-Meshad, who then led Iraq’s nuclear program, was beaten to death in a Paris hotel room; his killer was never identified (Russell, 1981). In 1990, Gerald Bull, a Canadian engineer and expert in long-range artillery who reportedly provided advice to both Iran and Iraq, was shot and killed outside his apartment in Brussels; authorities ruled out robbery as a motive when they found $20,000 left untouched in his pocket (Fried, 1990).

The attacks in Iran

The most recent killings of nuclear scientists involve the Iranian nuclear program. In an aggressive September 2011 speech to the International Atomic Energy Agency (IAEA) General Conference, Abbasi, the leader of Iran’s Atomic Energy Organization, denounced the killings of Ali-Mohammadi, Shariari, and Rezaeinejad, calling them “our scientists and experts.” He linked their deaths to recent international pressure, arguing that their names and addresses (along with other scientists’) were included in documents related to sanctions levied against Iran by the UN Security Council and the European Union (Abbasi, 2011: 6). Although the exact meaning of Abbasi’s speech is obscured by a poor translation, he seemed to hold the IAEA at least partially responsible for the killings.
...

[Vayutuvan]

The very fact that The Bulletin had to publish a lengthy article as late as 2020 says something. There could be some truth to the machinations by CIA/5eyes/Mossad to kneecap nuclear programs of countries whose rise could threaten the West's supremacy in arms/space as well as protecting Israel's interests in West Asia. Since India did not make too much of noise all these years, we did not get enough attention.

Now is the right time to ask raise these issues and put them up for public debate in India that the rise of India is imminent.

Squeaky wheel gets the oil

[A_Gupta]

What is publicly known from the GISAT Failure Analysis Committee:
https://www.newindianexpress.com/nation ... 34484.html

The Failure Analysis Committee (FAC) set up by ISRO found that the GISAT-1 mission failed owing to damage in the soft seal in a critical valve which resulted in lower pressure in the rocket's liquid hydrogen (LH2) tank, the space agency said on Friday.

[A_Gupta]

Unofficially what is known about the failure of NAVIC:
https://www.rediff.com/news/report/what ... 250219.htm

[Amber G.]

Unofficially what is known about the failure of NAVIC:
https://www.rediff.com/news/report/what ... 250219.htm

Adding some background and some basic but technical discussion for NAVIC - Hope this is useful.
(FWIW: Basic background - Again ignore if not interested or already known )

IRNSS and the Rubidium Clock Failures

The IRNSS — now called NavIC — is India’s own GPS-like navigation system. It consists of a constellation of satellites, each carrying atomic clocks (specifically Rubidium clocks) that are essential for precise timekeeping and navigation accuracy.

What happened with the clocks?

Around 2017, it was reported that 7 out of 9 Rubidium atomic clocks onboard IRNSS-1A had failed.

These clocks were supplied by the Swiss company SpectraTime.

With all three clocks on IRNSS-1A failing (each satellite has 3 for redundancy), the satellite was y rendered non-functional for navigation purposes.

Why do some suspect sabotage?:

Some suspicions arise - though no formal evidence of sabotage has been made public. - The reasoning (my take - from what I read ) goes:

Unusually high failure rate -- A triple failure is rare.
Other users of SpectraTime clocks — like Galileo also faced clock anomalies (though they weren’t total failures like IRNSS-1A).

Strategic significance:
NavIC reduces India's dependence on GPS or other foreign systems.
Has military applications.
A failure at a critical phase raises eyebrows.
There’s long-standing skepticism in India about foreign supply chains being "trojan horses" — intentionally or otherwise.
Opaque failure analysis-: (ISRO didn't release a full technical breakdown publicly.)

My take:

- Sabotage is plausible, but not proven.

- It's far more likely that this was a design flaw or production defect in a specific batch of SpectraTime clocks ( especially because other systems like Galileo also saw issues).

I think (consistent with many including Wiki ) the failures were due to a malfunctioning feed-through capacitor in the clock's power supply, leading to excessive temperature rise and subsequent failure.

IOW - The issue was traced to a specific component within the clock's power supply system.
. Also AFAIK ISRO has not indicated any suspicion of sabotage.

What has India done since?:

ISRO now aims to build its own atomic clocks for future NavIC satellites — a smart and strategic move.

Later satellites like IRNSS-1H and IRNSS-1I were launched to replace IRNSS-1A.

There’s been a push for greater self-reliance in key technologies — part of the broader "Atmanirbhar".
---

[Suraj]

BBC: Galileo satellites experiencing multiple clock failures

The onboard atomic clocks that drive the satellite-navigation signals on Europe's Galileo network have been failing at an alarming rate.

Across the 18 satellites now in orbit, nine clocks have stopped operating.

Esa is also in contact with the Indian space agency which is using the same clocks in its sat-nav system. So far, the Indians have not experienced the same failures.

SpaceNews: Rash of Galileo clock failures cast doubt on timing of upcoming launches
It's been stated just days ago and I'll repeat - please stop trying to immediately jump to conclusions. There may or may not be substance to conspiracies, but that's to be established after a thorough analysis and not before that.

[SSridhar]

Voice of ISRO launches Ganesan Grahadurai retires after 38 years - WION

When a rocket launch mission by the Indian Space Agency (ISRO) is in progress, for journalists at the spaceport and those watching the live stream, only one voice matters - that of Ganesan Grahadurai.

As the Range Operations Director at the Satish Dhawan Space Centre, he monitors multiple parameters during a launch and makes all-important announcements or "callouts" regarding the performance of each rocket stage and the overall progress of the mission. After having served ISRO for over 38 years, Grahadurai is stepping down on 30th May 2025.

With his iconic voice and unique pronunciation, when Range Operations Director G. Grahadurai announces, "First stage performance normaalll... Second stage performance normaalll... Third stage performance normaalll... Satellite injection conditions are achieved... Satellite injected," it is a sign of relief and joy for the ISRO leadership at the Mission Control Centre, as well as the Indian space enthusiasts watching the live stream. However, these announcements are only a minor part of the Range Operations Director's role.

The Range Operations Director is responsible for coordinating between the rocket team, satellite team, and spaceport team, providing technical and logistical support. It involves taking part in supervising the health checks of the rocket, satellite, tracking systems, radars, etc. Finalising the countdown timing for every mission is also a crucial role of the Range Operations Director.

About the love and adulation that he receives from the space enthusiast fraternity, Grahadurai says, I have to thank God and my parents for my voice. "As the Range Operations Director, my role is to announce the events clearly to the public. In that process, due to emotional attachment and complete involvement towards every mission, my voice has a unique, soulful feel and tone," he suggests.

Grahadurai's voice and announcements have also become quite the viral phenomenon on social media and among the space enthusiast community. Even at home, Grahadurai has admirers who try and mimic him. "Not only my grandchildren, but many friends, relatives and the public have fun by mimicking my announcements and voice," he says laughingly.

Hailing from Sivakasi in Tamil Nadu, the city known for firecrackers, Grahadurai's life journey took him to the Indian spaceport in Sriharikota, Andhra Pradesh, where he has contributed to 96 of India's 101 rocket launches, in various functional designations. Since January 2020, in his role as Range Operations Director, he has made announcements for 24 of ISRO's 101 rocket launches, which is a record in itself.

An Electronics and Communications Engineer by qualification, Grahadurai's notable work includes developing ISRO's Mission Control Centre, the upcoming Gaganyaan Control Facilities for the Human Spaceflight programme, and Range Operations infrastructure at the upcoming spaceport in Kulasekarapattinam, Tamil Nadu.

"Indeed, I will miss the roles and responsibilities of being the Range Operations Director, and the announcements during a launch mission. I am very emotionally attached to the Indian Space Research Organisation (ISRO), and particularly the Range Operations Director role," he told WION's Sidharth M.P. on his last working day at the spaceport.

To his admirers and well-wishers, he says, "In future, the Range Operations Director's desk will get a voice better than mine, which will continue to mesmerise all of us."

[Amber G.]

Launch of Axiom 4 slated for 11th June 2025 for sending the first Indian Gaganyatri Shubhanshu Shukla to ISS is postponed due to LOX leakage: ISRO
( Engineers found a liquid-oxygen leak on the Falcon 9 booster during post-static fire tests.
This follows earlier weather delays, prompting ISRO to stand down the mission until repairs are done and a new launch window is available.

[Vayutuvan]

Why are we not sending a gaganyaatriNi, i.e a woman, to ISS? That would send a message to the world that we are neither misogynist nor patriarchal.

[gakakkad]

Launch of Axiom 4 slated for 11th June 2025 for sending the first Indian Gaganyatri Shubhanshu Shukla to ISS is postponed due to LOX leakage: ISRO
( Engineers found a liquid-oxygen leak on the Falcon 9 booster during post-static fire tests.
This follows earlier weather delays, prompting ISRO to stand down the mission until repairs are done and a new launch window is available.

its a spacex launch. why is isro making decisions?

[Amber G.]

Launch of Axiom 4 slated for 11th June 2025 for sending the first Indian Gaganyatri Shubhanshu Shukla to ISS is postponed due to LOX leakage: ISRO
( Engineers found a liquid-oxygen leak on the Falcon 9 booster during post-static fire tests.
This follows earlier weather delays, prompting ISRO to stand down the mission until repairs are done and a new launch window is available.

its a spacex launch. why is isro making decisions?

ISRO is involved in this SpaceX launch (I actually was following ISRO media) because the mission includes first Indian Gaganyatri Shubhanshu Shukla to ISS (who will be traveling to the International Space Station as part of the Axiom 4 mission.)

This mission is significant for India's human spaceflight program, Gaganyaan, which aims to launch Indian astronauts into space.

Although SpaceX is operating the Falcon 9 rocket, ISRO is collaborating with SpaceX and Axiom Space due to Shukla's participation in the mission. The decision to postpone the launch was made jointly after a liquid oxygen leak was detected during pre-flight tests. Both ISRO and SpaceX confirmed the delay, with SpaceX stating they need more time to repair the issue and validate the rocket's performance before proceeding.

Link:https://x.com/isro/status/1932605652360442184

[Amber G.]

ISRO Deploys Satellite Payload From Uttar Pradesh For The First Time, 15-Kg Rocket Hits 1.1 Km Altitude In Test Launch

[Amber G.]

NASA and ISRO are launching their joint satellite mission, NISAR, on June 18. NISAR uses synthetic aperture radar to capture high-resolution images of Earth, detecting changes down to the centimeter level, regardless of weather or time of day. The satellite will provide freely available global data, aiding disaster management, climate change understanding, and agricultural monitoring.

Its features include:

Monitoring land and ice surfaces twice every 12 days
Mapping flooded vegetation and wetlands
Estimating soil moisture levels for optimal irrigation
Tracking ice sheet flow, glaciers, coastal erosion, and oil spills

The $1.5 billion project aims to improve our understanding of Earth's ecosystems and climate change impacts.

[suryag]

Anyone here knows whats happening with Gp.Capt.Shukla's flight ? I keep seeing delays after delays

[Amber G.]

Anyone here knows whats happening with Gp.Capt.Shukla's flight ? I keep seeing delays after delays

Scheduled Launch Status
May 29 First delay – Dragon capsule issues
June 8 Delayed – rocket not launch-ready
June 10 Postponed – final operations and LOX leak
June 11 Delayed – weather and quarantine protocols
June 19/22 Deferred – ISS module checks
June 22 Latest delay due to ISS operational review


The current window remains open until June 30, with the next available opportunity thereafter in mid‑July

[Prem Kumar]

NASA and ISRO are launching their joint satellite mission, NISAR, on June 18. NISAR uses synthetic aperture radar to capture high-resolution images of Earth, detecting changes down to the centimeter level, regardless of weather or time of day. The satellite will provide freely available global data, aiding disaster management, climate change understanding, and agricultural monitoring.

Postponed to July now

[Amber G.]

Group Captain Shubhanshu Shukla’s first message from Space: “Namaskar Mere Pyare Deshwasiyon. Kaafi Saal Baad Hum Phir Wapas Antariksh Mein Pohonch Gaye Hain. Kamaal Ki Ride Thi. Mere saath Mere Kande Pe Tiranga Hai..”

<video.He finished with “Jai Hind, Jai Bharat”.

[chetak]

What Indian media hasn’t sufficiently highlighted is that ⁦@isro⁩ is a full partner with ⁦@NASA⁩ & ⁦@SpaceX ⁩ in #Axiom-4 mission to the international space station (ISS), investing Rs 550 crore & top ISRO scientists stationed in the US to help with the launch

[S_Madhukar]

The Polish Slavosz of Ax-4 mission - his wife is an MP in the Polish Parliament and she articulated nicely that she wishes Poland to be a space power like US and not be reliant on just 1 company like SpaceX. Wants to encourage Poles globally to come back to Poland and contribute towards this effort.

Hope ISRO and GoI recognise the ambition and invest in our own capabilities

https://youtu.be/kc7EUGFG5ck?si=uYvGydvQtp6w_knM

[S_Madhukar]

Ax-4 the astronauts dock and enter the ISS -

https://youtu.be/dw7xgQtDLrg?si=q75rDYoHGs6nZJ6f

Ax-4 welcome speeches -

https://youtu.be/DeS9plZ9JVk?si=EgKxH7KQ68e0DpqC

PM Modi talks to Astronaut Shukla

https://www.youtube.com/live/3wO8qQtq-d ... BkI3hbUHz4

[chetak]

[S_Madhukar]

Chipak are all over this claiming we just bought a expensive ticket to ride unlike the Han who have their own station…Bakis hoping to get a free ride from their Masters

[Prem Kumar]

https://timesofindia.indiatimes.com/ind ... 149971.cms

India to fast-track launch of 52 defense satellites

1) Expected start in April 2026. Planned to be completed by end of 2029
2) 21 by ISRO and 31 by 3 private players
3) Efforts are on to compress timelines
4) 3 HAPS pseudo-satellites also being considered
5) For comparison, China had 36 satellites in 2010 --> they have 1000 today, out of which 360 are dedicated to ISR missions

Hope we have Plan A, B and C. We should seriously accelerate these timelines but also expect that some % of these satellites & launches will fail. Have backup satellites and launch vehicles ready (if SSLV fails, use PSLV, else GSLV). Even create additional spaceports. Can't have our snail's pace of 6 months failure analysis and 3 months rectification, during which everything comes to a standstill. Yes, those detailed failure analyses are necessary but programs should continue in parallel and not get stalled

We have to get serious about defense-space capabilities as a nation

[Amber G.]

Group Captain Shubhanshu Shukla of Indian Air Force reflects upon his two weeks on the International Space Station during the Axiom-4 Farewell Ceremony. “Saare Jahan Se Aacha

[SSridhar]

Sharp-eyed US-Indian satellite set to launch July 30 to monitor Earth's surface, warn of natural disasters

The first equal partnership between NASA and the Indian Space Research Organisation (ISRO) is set to take flight on July 30 with the launch of the NISAR Earth-observation satellite.

Standing for NASA-ISRO Synthetic Aperture Radar, NISAR will scan our planet to provide the most detailed map of the surface yet, and the most sensitive, able to see the ground or ice creeping by degrees of less than a centimeter.

This sensitivity, as well as the overall coverage of Earth that NISAR will provide, will be essential for helping to avert, or minimize, the effects of natural disasters, from earthquakes and volcanoes to land subsidence and swelling, plus the movement, deformation and melting of ice sheets and glaciers, and the tracking of wildfires and floods. Even the smallest shifts in the landscape could one day prove to be the precursor to a major disaster. For example there are "slow" landslides, where a mountainside or cliff might move by just a few centimeters per day, before reaching a tipping point and crashing down. NISAR will be able to see that slow creep, or the subtle movement of tectonic plates, and warn when more serious disasters might be about to take place.

"Where moments are most critical, NISAR's data will help ensure the health and safety of those impacted on Earth as well as the infrastructure that supports them," said Nicky Fox, associate administrator of NASA's Science Mission Directorate, in an agency press conference on July 21.

"They can be very small changes, but they can have enormous implications," added Karen St. Germain, the director of NASA's Earth Science Division.

NISAR will achieve this thanks to its dual-frequency band radar. The L-band radar, which transmits microwaves between 1 and 2 gigahertz (GHz), was built by NASA's Jet Propulsion Laboratory (JPL) in Southern California, while ISRO provided the S-band radar operating between 2 to 4 GHz. The different frequencies can detect different things on the ground. The S-band is sensitive to vegetation and foliage, for example, whereas the L-band can see through the trees to monitor the bare surface, be that rock or ice. And because neither instrument is encumbered by clouds, the coverage of the surface is total, mapping the entire globe in unprecedented detail every 12 days.

"These two radars work together to accomplish science that neither can see on their own," said Wendy Edelstein, who is NISAR's deputy project manager at JPL.

Both radars feed into NISAR's giant antenna, which is 12 meters (about 40 feet) in length; when unfolded, it's about the size of a tennis court. "The surface material is a lightweight mesh that allows the whole antenna to fold very compactly and be stowed for launch," said Edelstein.


(Image credit: NASA/JPL-Caltech)

It's this antenna that gives NISAR its special powers of high resolution, thanks to a technique called synthetic aperture radar.

Synthetic aperture radar takes advantage of the fact that NISAR is moving. The spacecraft beams down radar pulses while flying along, and because of this motion, the area on the ground covered by each radar beam while switched on is about 10 kilometers (6 miles) long. This is far larger than the actual size of the antenna on the spacecraft — hence why it's called synthetic aperture radar. Ordinarily, this motion would incur a motion blur, but by beaming thousands of radar pulses per second to capture the fine detail, NISAR is able to see in high resolution.

"We sort of build up a movie, frame by frame, of every point on the Earth's surface," said Paul Rosen, who is NISAR's project scientist at JPL.

By flying in an exact-repeat orbit — meaning it passes over the exact same ground track, every 12 days in this case — NISAR will be able to combine its synthetic aperture radar with another technique called radar interferometry

"We fly along, collect the echoes, make the image, and come back again at a later time and make another image, and count the peaks and troughs of the radar waves and use them as a yardstick to measure how the ground is moving over time," said Rosen.

NISAR will head into space on July 30 on board an Indian Geosynchronous Satellite Launch Vehicle (GSLV) rocket from ISRO's Satish Dhawan Space Center in Sriharikota, which is on India's southeastern coast.

"NISAR is an equal 50/50 partnership between NASA and ISRO," said Edelstein. Fox stated that NASA had spent $1.2 billion on the mission, in particular funding the L-band radar, plus the antenna and its boom. ISRO contributed the S-band transmitter, the spacecraft bus, solar arrays and the launch vehicle.

None of the Indian contingent on the project were in the press conference — because of time zone differences, according to NASA. However, in January, the co-lead of the ISRO science team at the Space Applications Centre in Ahmedabad, Deepak Putrevu, said in a statement. "This mission packs in a wide range of science toward a common goal of studying our changing planet and the impacts of natural hazards."

Ten days after launch, NISAR will be in position to begin unfurling its giant antenna, and by day 65 the first full-frame science images will be produced.

"I've spent my entire career working on radar missions for JPL, and NISAR is the highlight for me," said Edelstein. "I can't wait to see the science that it produces and the impact that it has. I think it will help people around the world."

[Prem Kumar]

Prayers for a successful launch. Need Dilbu here

The precision to come back on the exact same track after 12 days must be exacting. Plus the error correction codes for any drift

Interesting that the L-band from NASA is foliage-penetrating. IAI's ELM-2112FP uses L-band to detect objects 10s of meters inside deep foliage

All this tech can go into our future SAR satellites & UAVs for defense purposes.

[Amber G.]

Prayers for a successful launch. Need Dilbu here

The precision to come back on the exact same track after 12 days must be exacting. Plus the error correction codes for any drift

FWIW: Here's some explanation for those interested in technical details

It is in sun-synchronous orbit (SSO) - a special kind of polar orbit in which the satellite passes over the same region of the Earth at the same local solar time on each pass.

Think of it this way: if NISAR flies over Delhi at 10:30 AM local solar time today, it will do so again 12 days later, also at 10:30 AM.

This consistency is crucial for comparing images over time with the same shadows, lighting, and solar angle—ideal for detecting tiny changes on Earth’s surface.

- How does it stay synchronized?
This is where clever orbital physics comes in.

Altitude (~743 km): This sets the satellite's speed and period—it orbits Earth in about 98–100 minutes.
Inclination (~98°): It orbits nearly pole-to-pole, allowing full Earth coverage as the planet rotates underneath.
Earth’s shape helps: Earth isn’t a perfect sphere—it’s slightly bulged at the equator. That bulge causes the orbit to precess (rotate) slowly.

Engineers design the orbit so that this natural precession causes the satellite’s orbital plane to rotate ~1° per day, keeping pace with the Earth’s movement around the Sun. This way, the orbit remains aligned with the Sun.

So over days and weeks, the satellite "sweeps" across the entire globe, always returning to the same spot under the same sunlight conditions.

- Why revisit every 12 days?
NISAR is in what’s called a 12-day repeat cycle, meaning it will follow the exact same ground track once every 12 days.

In between, it flies slightly different tracks, shifted west-east each day.

Over 12 days, it builds up a dense map, and then it repeats from day 13 onward.

This means scientists can:

Detect movement (like a glacier shift or land deformation) to within a few millimeters.

Compare two radar images (before/after) to make interferograms—which show ground motion patterns with precision.

Maintaining this precision is technically challenging. That's why:

Satellites have onboard GPS and sometimes star trackers to monitor their position and attitude.

Engineers use error correction algorithms and orbital control maneuvers (e.g., small thruster adjustments) to maintain or fine-tune the orbit.

Ground stations continuously track the satellite and upload ephemeris updates (precise path corrections).

This setup allows for highly accurate, repeatable Earth observation, vital for tracking changes like landslides, glacier shifts, and even infrastructure strain.

(- Valued at about US $1.5 billion, this is one of the most ambitious Earth‑observation efforts ever
- Represents a first-of-its-kind hardware partnership between NASA and ISRO, with payloads and systems developed across the U.S. and India)

[Amber G.]

All this tech can go into our future SAR satellites & UAVs for defense purposes.

ISRO’s RISAT series (e.g., RISAT-2B) and the newer DRDO’s EMISAT are examples of defense-focused SAR and ELINT satellites.

(NISAR can accelerate domestic know-how and improve next-gen ISR..but from what I know Some parts of NISAR’s tech are developed by NASA/JPL, which may be governed by ITAR and not legally be repurposed for Indian military use without U.S. approval or domestic re-engineering)

(NISAR is bus-sized (2800 kg) and very expensive ($1.5 billion)—not suitable for tactical or mobile military use...Defense systems often need smaller, agile, and more disposable platforms—e.g., microsats or UAV pods.. and NISAR is built for wide-area, slow-changing targets (eg glaciers) while we may require observig rapid canges and rapid revists (not 12 days)

But certainly the tech is reusable...

[drnayar]

All this tech can go into our future SAR satellites & UAVs for defense purposes.

ISRO’s RISAT series (e.g., RISAT-2B) and the newer DRDO’s EMISAT are examples of defense-focused SAR and ELINT satellites.

(NISAR can accelerate domestic know-how and improve next-gen ISR..but from what I know Some parts of NISAR’s tech are developed by NASA/JPL, which may be governed by ITAR and not legally be repurposed for Indian military use without U.S. approval or domestic re-engineering)

(NISAR is bus-sized (2800 kg) and very expensive ($1.5 billion)—not suitable for tactical or mobile military use...Defense systems often need smaller, agile, and more disposable platforms—e.g., microsats or UAV pods.. and NISAR is built for wide-area, slow-changing targets (eg glaciers) while we may require observig rapid canges and rapid revists (not 12 days)

But certainly the tech is reusable...

as someone said., the US optical spy sats [ KeyHole 11 or KH11 ] are similar to Hubble satellites , have mirrors comparable in size to Hubble's (2.4 meters) and utilize similar electro-optical digital imaging, KH11s are bigger as well..looking in the other direction .. and there are quite a few of them.. one can just imagine how much each would cost!

[Prem Kumar]

Insightful posts as always, Amber G. Have to oil up my crusty brain to understand orbital mechanics

I think we will need all kinds of satellites, augmented by all kinds of UAVs, HAPS, GMTI-Aircraft etc. Some satellites will be large, expensive. Many will be small, agile and disposable. GISAT was geo-synchronous and had dual-use - we will need some birds of the geo-sync category too

We have too few milsats. Hope the Govt is serious about the 50+ they want to launch in the next 3 years. Even with those, we would have about 1/20th of China's numbers. RISATs are end of life, an EOS failed recently and there were reports that Cartosat-3's actual resolution being 50 cm against the target 30 cm + we have too few of them, which meant we bought satellite imagery from Maxar, which Pakis also did (+ the lizards fed them realtime data)

FOPEN radars would be great for detecting Maoist movements, infiltrating Jihadis, camps etc. Ground Penetrating radars - we needed them yesterday - would have saved scores of lives from Maoist IEDs

We should actually be world-leaders in this area, given our diverse terrain and our enemies