Space & Physics
Need of the Hour – Evading the Kessler Syndrome
In 1978, Donald J. Kessler, an astrophysicist, predicted collisions between satellites can get out of hand as their population keeps increasing.
In 2009, the Iridium 33 and Kosmos 2251 satellites collided to produce as many as 2,000 debris fragments, spraying 10 cm wide pieces in every direction – at speeds faster than a bullet.
If any of these ever struck the ISS, orbiting closely, then all hell can break loose! Remember that scene in Gravity (2013) when Sandra Bullock’s character gets flung around? Well, it’s just one of several worse-case scenarios.
Even today, these space debris hover there, too close to be completely risk-free to the ISS.
The US’ operate a Space Surveillance Network that tracks these debris, along with more than 20,000 fragments. They comprise old rocket booster stages, junk satellites, missile components from anti-satellite launches.
However, very tiny pieces of fragments (<10 cm) can still be missed by ground radars. Space debris can include spent rocket stages, or defunct satellites drifting in space.
And a technical fix in orbital debris removing technology arose.
Last month February 18th saw the launch of the Active Debris Removal by Astroscale-Japan (or ADRAS-J) satellite from Rocket Lab’s launch station in New Zealand. ADRAS-J is yet to actually demonstrate debris removal, as it’s parked in a rendezvous orbit in preparation for the demonstration later this month.
In 2022, the UK stated Active Debris Removal (ADR) as being vital to their Plan for Space Sustainability to “become tomorrow’s norms in space operation”.
Space agencies across the world now issue commands for ‘collision avoidance maneuvers’ (CAM) when satellites cross within a certain radius.
In fact, the Indian Space Research Organization (ISRO) actually made public a trend showing the number of CAM commands issued rising every year. Such close-calls will only increase with the cumulative increase of satellites in orbit.
Here’s a plot from the European Space Agency’s (ESA) 2022 Space Environment Report.

A plot of the number of space debris against time. The legend indicates the various types of space debris (rocket, satellite parts etc.). Credit: ESA
But the problem is that – these satellite numbers are rising exponentially in such a short time – with mega-constellations entering center stage.
SpaceX launched the Starlink initiative, to demonstrate connectivity even in the remotest parts of the world.
However, they alone have 5,504 satellites out there to date, all at low-earth orbit – under 600 km, which is quite where the crowd of satellites are now. That’s about 58% of the 9,414 operational satellites out there. And this happened metaphorically overnight – in the past few years. SpaceX plans to operate some 42,000 satellites in a decade.
The fear is that unregulated growth of satellites – or even satellite litter that are defunct – can make what is known as the Kessler syndrome, a reality.
When Donald Kessler anticipated a chain reaction …
In 1978, Donald J. Kessler, an astrophysicist, predicted that collisions between satellites can trigger a domino effect of other satellite collisions above a certain threshold. Dubbed the Kessler syndrome, it’s a worst-case scenario possible in outer space, when earth’s orbit becomes impossible to thrive in or operate from.
To partly address the growing clutter of low-earth orbit satellites, the US’ Federal Communications Council (FCC) has put up legislation to have newly launched satellites deorbit 5 years after operations.
The irony is that the Kessler syndrome was foreseeable, except it was ignored by policymakers until they simply couldn’t.

Scientists building a satellite at RAL Space. Credit: UK STFC / Wikimedia
Western countries have taken some onus of responsibility into these space sustainability initiatives, simply because countries like the US own most of the satellite infrastructure operating in orbit.
From space shuttles, rockets, space planes and the lunar lander that brought Neil Armstrong and Edwin Aldrin to the moon, the Space Age heralded a brand new era for space technologies and research. But no space technology probably had more societal impact than the satellite.
Seen vital for development and infrastructure, satellites are now ubiquitous, manufactured not just by space agencies, but also by engineering labs in universities, private companies and start-ups across the world.
However, our costly endeavor to improve human lives are breeding new problems. And as a last resort, engineers are at it again to come up with technical fixes.
But weren’t the technical risks understood if Kessler expressed his concern in the 1970s?
Satellites, just like any technology, come with its set of benefits and risks. The benefits of satellites are obvious to many – phone connections, weather forecasting, banking, studying climate change, and the list goes on.
At the end of a satellite’s lifespan though, many just stay there, as defunct satellites.
Sure, there’s a ‘graveyard’ orbit where satellites can be made defunct after pushing them to a higher orbit to lay to rest forever. But not every defunct satellite is. In fact, 60% of all satellites are defunct. The operational satellites constitute a tiny minority.
Partly to do with this mess is a lack of priority. The Space Race played out during the peak of the Cold War when both the US and Soviets wanted to demonstrate technological superiority.
However, the outer orbit isn’t just a matter of mediating traffic or cleaning debris either.
Space militarization has raised fears. Much of the initial Space Race began with the US and Soviets fearing the other could surveil over their national boundaries. But the tensions have now made headlines, with the ongoing Russian invasion of Ukraine, with the US alleging that the Russians are developing a satellite that can drop nuclear weapons against the West. Building such a weapon would be violative of the 1967 Outer Space Treaty, in addition to several other regulations against weapons of mass destruction (WMDs).
There’s also anti-satellite launch systems firing repurposed ballistic missiles into space missiles. The US, Russia, China and India all possess this technology – and have the capacity to threaten orbital infrastructure – civilian or military. But the consequence of losing control over the weapons, is to hit the threshold dictated by the Kessler syndrome.
We’ll need to bear in mind that even technical fixes can’t fix design thinking. When planners aren’t held accountable, for their individual decisions – such avoidable doomsday disasters become a talking point.
Space & Physics
NASA announces crew of Artemis III at live event
Artemis III will be the agency’s next human space exploration mission paving the way for humanity’s planned return to the moon in 2028.
At 20:30 hours IST yesterday, NASA’s Johnson Space Center in Houston, Texas held a live event their engineers, scientists, the astronaut corps and the media attended. The space agency officially announced the crew of Artemis III, the agency’s next human space exploration mission, paving the way for humanity’s planned return to the moon in 2028, over fifty years after the Apollo program.
Half-way through the hour-long presentation, Jared Isacson, the NASA administrator, walked to the dais to announce the all-men crew of Artemis III: NASA mission commander Randy Bresnik, mission specialists Andre Douglas and Frank Rubio, and European Space Agency pilot Luca Parmitano, an Italian national.
Three of the astronauts excluding Douglas, a US Coast Guard reserve, are both spaceflight and military veterans. Bresnik, a US marine colonel and test pilot clocking 7,000 hours, commanded the International Space Station. So did Parmitano, the first Italian commander of the station, and who survived a 2013 spacewalk when water abruptly filled his helmet and had an asteroid named after him. Rubio, a US army helicopter pilot, holds the record for the longest time spent in space.

Screengrab from the YouTube livestream of the event at NASA Johnson Space Center, Houston, Texas. Credit: NASA
Mission timeline
The mission could take off in the second-half of 2027. Originally, NASA planned Artemis III to be the first soft-landing lunar mission since 1972’s Apollo 17, with a slated launch date in 2028. However, in March, the agency updated mission timelines, with the mission relegated for testing its mission critical docking mechanism, ahead of Artemis IV’s planned soft-landing that year.
The crew will fly aboard a Space X Orion capsule into low-earth orbit. Unlike its predecessor, Artemis III won’t leave earth orbit and conduct a flyby past the moon. Instead, it will test life support systems and docking with Artemis’ era lunar landers, built by private space companies Space X and Blue Origin, the Starship Human Landing System (HLS) and the Blue Moon respectively. In addition, Artemis III will carry on science experiments, including using instrumentation to test effects of atmospheric drag upon the spacecraft, amidst hostile space weather.

The Apollo and Artemis-era lunar landers drawn to scale. Credit: NASA
Lunar landers
There has been skepticism whether the Blue Moon lunar lander’s launch schedule would be affected, in the aftermath of last week’s mishap involving New Glenn, the flagship rocket of Jeff Bezos-owned Blue Origin, exploding during a hot-static test ahead of its slated launch of Amazon’s satellites. The explosion destroyed the company’s custom-developed launchpad at Cape Canaveral Space Force Station in Florida. However, the company CEO, David Limp, posted on X, they’ll return to full-swing operations latest before the end of this year.
Whereas Starship HLS, the other lunar lander design, will feature a variant of the Starship rocket, with the latter design being still tested over repeated space flights in the past year.
Either lunar landers designed to ferry astronauts from lunar orbit to the surface, and back. In a future Artemis mission, the astronauts, who will ride aboard Space X’s Orion crew module from earth, will dock with the lander in lunar orbit, before transferring to the lander module.
It’s unclear which lander design’s slated to make the soft-landing attempt in Artemis IV.
Space & Physics
Engineers Develop Dual-Mode Propulsion System for Next-Generation Small Satellites
MIT engineers have developed a dual-mode propulsion system that combines chemical and electric thrusters, giving small satellites greater flexibility in space
Dual-mode propulsion system technology developed by MIT engineers could give small satellites the ability to perform both powerful manoeuvres and fuel-efficient long-distance travel using a single propellant source.
Small satellites have transformed space research by making missions cheaper and more accessible. Yet they continue to face a fundamental limitation: propulsion.
Traditional chemical thrusters provide powerful bursts of speed but consume large amounts of fuel. Electric propulsion systems, on the other hand, are highly efficient but generate only gentle thrust over long periods. Spacecraft designers have typically had to choose between the two.
Engineers at the Massachusetts Institute of Technology (MIT) now believe they have found a way to combine both approaches in a single compact system, potentially giving small satellites the agility of much larger spacecraft.
The breakthrough centres on a special propellant capable of powering both chemical and electric thrusters from the same fuel tank.
“If you can have chemical and electrical propulsion in one small package, it’s the best of both worlds,” said Amelia Bruno, lead author of the study and a former postdoctoral researcher in MIT’s Department of Aeronautics and Astronautics, in a media statement.
“This opens the door for small satellites to do even more science, more observations, and more interesting missions, all on a smaller and cheaper platform.”
The findings have been published in the Journal of Propulsion and Power.
Dual-Mode Propulsion System Combines Two Technologies
The MIT team tested a propellant known as Advanced SpaceCraft Energetic Non-Toxic propellant, or ASCENT. Originally developed by the U.S. Air Force as a safer alternative to hydrazine, ASCENT was designed for chemical propulsion systems.
Researchers discovered that the same propellant can also power miniature electric propulsion devices known as electrospray thrusters.
These tiny thrusters use electric fields to charge particles within a liquid propellant and eject them into space, creating precise and fuel-efficient thrust. While chemical thrusters are ideal for rapid manoeuvres, electrospray systems are better suited for gradual course corrections and long-duration journeys.
By enabling both systems to share a single fuel source, the technology could significantly reduce the size and complexity of propulsion systems aboard CubeSats and other small spacecraft.
Dual-Mode Propulsion System Could Expand Deep-Space Missions
Dual-mode propulsion system can expand deep-space missions. The implications extend beyond Earth orbit.
CubeSats have become popular for scientific research and technology demonstrations, but their limited propulsion capabilities have restricted their use in deep-space missions.
According to Paulo Lozano, the Miguel Alemán Velasco Professor of Aeronautics and Astronautics at MIT, the new system could change that.
“We could send CubeSats to Mars, or the asteroid belt, where they could make the journey slowly, using electrospray thrusters,” he said.
“You could then use your chemical thrusters to quickly move to look at interesting features. You could have a lot more flexibility to do a lot more things.”
Testing the Technology
To evaluate the propellant’s performance, the researchers filled small CubeSat reservoirs with ASCENT and tested them in a vacuum chamber designed to simulate conditions in space.
During the experiments, electrospray thrusters powered by ASCENT successfully generated thrust for extended periods, in some cases operating continuously for up to 100 hours.
NASA Mission Will Put the Technology to the Test
The next major test will come later this year.
MIT researchers are working with NASA on the Green Propulsion Dual Mode mission, a CubeSat that will carry both chemical and electrospray thrusters powered by a single propellant tank. Scheduled for launch in November, the mission will be the first demonstration of such a system in a small spacecraft.
If successful, the mission could help pave the way for a new generation of versatile satellites capable of switching between rapid manoeuvres and highly efficient long-distance travel.
Space & Physics
India Semiconductor Mission: ‘It’s Not About Fabs. It’s About Building An Entire Ecosystem’
India Semiconductor Mission is reshaping the country’s chip ambitions. Neelkanth Mishra explains the opportunities, challenges and long-term strategy.
As India pushes ahead with its semiconductor ambitions under the India Semiconductor Mission (ISM), questions remain about where the country can realistically compete and how long it will take to build a viable ecosystem. In this exclusive conversation with Education Publica Editor Dipin Damodharan in Mumbai, Neelkanth Mishra, Chief Economist at Axis Bank and Head of Global Research at Axis Capital, draws on two decades of experience tracking the global semiconductor industry to explain India’s advantages, constraints, and long term trajectory. He is also a member of the advisory committee of the government’s India Semiconductor Mission and part-time Chairperson of the Unique Identification Authority of India (UIDAI). Edited excerpts.

How the India Semiconductor Mission Is Shaping the Industry
Let me start with asking something out of curiosity – how did you get interested in semiconductors in the first place?
When I joined Credit Suisse First Boston in 2003 in Singapore, the person who hired me was heading Asia technology research and was also the lead analyst for semiconductor foundries such as TSMC and UMC. I was hired to cover IT services, but he wanted help in building the semiconductor research franchise.
That led me to start reading about how chips are made. At that time, the industry was transitioning from 130-nanometer to 90-nanometer nodes, and copper was being introduced to replace aluminum due to resistance issues. There were challenges around yields because copper was seeping into substrates. I remember writing my first note around this issue after going through technical papers.

That note became quite popular, and it gave me the confidence to continue covering semiconductors. I spent a lot of time travelling to Taiwan, studying DRAM cycles, capex cycles, node transitions, and the broader global semiconductor ecosystem. Eventually, I moved to Taipei and began covering chip design companies such as MediaTek.

At that time, were you also tracking what was happening in India?
India has had chip design activity for a long time, even in the 1990s. Companies like Texas Instruments, Cadence, and Synopsys were recruiting from Indian campuses. Many engineers built long careers in these firms.
However, India did not have domestic chip manufacturing or strong Indian-owned chip design companies. By the mid-2000s, global firms such as Nvidia, Broadcom, and Intel began setting up design centres in India. So the design ecosystem was growing, but it was largely driven by global companies.
It is only in the last four to five years that more serious efforts have begun toward building Indian-owned capabilities.
So what changed in the last few years? Was it policy, or something else?
Policy has played a role. The Design Linked Incentive (DLI) scheme has been an important catalyst. We are seeing some early success. At the same time, there is also an evolutionary factor at play. Engineers who moved abroad 20–25 years ago are now at a stage where they have both the experience and financial capacity to take entrepreneurial risks. Many also want to return to India.

Another important factor is the growth of India’s electronics manufacturing ecosystem. As assembly volumes increase, there is greater awareness of what products need to be designed. Without that visibility into OEM pipelines, it is difficult to design chips.
Schemes like PLI for electronics manufacturing have helped build that awareness and ecosystem. As downstream industries grow, upstream opportunities in chip design also become clearer.
As US is good at designing chips, Taiwan and South Korea are good at manufacturing There’s always this question – should India focus on design, manufacturing, or packaging?
There is no either/or. India needs to participate across the value chain.
We already have a natural advantage in chip design, with about 20% of global design engineers based in India. Design is also less capital-intensive compared to manufacturing. In a $10 chip, $5–6 of value is captured by the designer, and in some cases even more.
At the same time, semiconductor manufacturing is a geopolitical necessity. It is not just a commercial issue but also a matter of national security. That is why governments provide significant subsidies for fabs.

However, manufacturing is a low-return business globally. Only a few companies like TSMC and Samsung have consistently generated returns above their cost of capital. Much of the value in the ecosystem is captured by design firms and by capital equipment suppliers, which operate in highly concentrated markets.
Therefore, India must build capabilities across the chain—from design to manufacturing to equipment and materials—if it wants meaningful value capture.
When we talk about building an ecosystem, how complex is that in reality?
It is extremely complex. The industry has multiple layers of specialization. For example, electronic design automation (EDA) tools are dominated by a few companies. Lithography, especially extreme ultraviolet, is controlled by a single company globally. Equipment for deposition, wafer slicing, and testing is also concentrated among a handful of firms.
Even the chemicals used in wafer cleaning are highly sophisticated and require extraordinary purity. A single wafer can take months to manufacture, involving hundreds of process steps.
So when we talk about semiconductors, it is not just about fabs. It is about building an entire ecosystem—equipment, materials, design, testing, and packaging. This is why it is a 15–20 year journey at least.

What about talent? Are we ready from a skills perspective?
In general, skilling in India is more of a demand problem than a supply problem. If there is sufficient demand, the industry tends to create the supply.
For example, there is already discussion about developing tens of thousands of chip testing engineers in India, and that is achievable. However, for cutting-edge technologies, there is a need for deeper investment in research.
As we move toward more advanced nodes—such as 7 to 12 nanometers—we will require significant high-end research capabilities. Countries like China took over 25 years to reach that level.
We need to invest not just in near-commercial research (TRL 6–9) but also in fundamental research (TRL 1–4), which creates long-term intellectual property. Government initiatives like the Anusandhan National Research Fund are steps in that direction, but overall R&D spending needs to increase.
What role should industry play in R&D?
Industry participation is essential. The government can catalyse investment, but companies will invest when they see potential returns.
We have seen this in pharmaceuticals, where Indian firms moved into R&D after reaching limits in generics. A similar shift can happen in semiconductors, but it will require scale, capital, and long-term commitment.

Where do startups fit into this picture?
Startups will have a significant role, particularly in chip design. Manufacturing is extremely capital-intensive, requiring billions of dollars in investment, which limits the role of startups.
However, in design and innovation, startups can play an important part. Many innovations in the semiconductor ecosystem originate from smaller firms, which are later acquired or integrated into larger companies.
To produce a globally competitive company, you need a large ecosystem of startups, experimentation, and risk-taking.
Coming to policy – what did India learn from ISM 1.0?
ISM 1.0 (India Semiconductor Mission) was a learning curve for everyone. It helped the government understand how to evaluate proposals, support companies, and manage operational challenges.
There were practical issues—from customs procedures affecting sensitive equipment to ensuring uninterrupted power supply. Semiconductor manufacturing requires extremely high reliability, and even a brief power outage can cause significant losses.
Another important learning is that the global industry is now more comfortable working with India. While India may not yet be the first choice, confidence has improved due to visible commitment and progress.
This increased comfort allows India to be more ambitious with ISM 2.0.

How important is policy stability?
Policy continuity is very important because these are long-term projects. Global firms value consistency in decision-making and relationships.
There is also a growing effort to ensure continuity in leadership within government institutions, which helps build expertise and trust over time.
Do we need a dedicated semiconductor research institution like IMEC?
There are existing efforts, such as the facility in Mohali, which supports defence-related applications. There are also discussions around creating IMEC-like research centres.
However, over time, the private sector will need to take a larger role in research. Government support is critical in the early stages, but for sustained innovation and competitiveness, industry-led initiatives are more effective. The government can act as the binding force or the catalyst that brings people to the table; however, I believe it is ultimately better if the private sector takes the lead. This creates a natural incentive for innovation and rigorous research. Beyond a certain point, government support becomes both fiscally unfeasible and operationally undesirable

If we look ahead 20 years, where do you see India?
On the design side, India can become much more significant. It is possible to see 10–15 large chip design companies and many smaller firms emerging.
On the manufacturing side, we could have several large fabs and potentially global players establishing operations in India, especially if a strong domestic design ecosystem develops.
For example, companies like TSMC tend to follow innovation ecosystems. If Indian design firms grow in scale and sophistication, it could attract global manufacturing investments.

Let me end with this – can India produce a company like Nvidia?
It is possible, but it requires a large ecosystem. Many Indians already occupy senior roles in global semiconductor companies and are involved in cutting-edge design work.
To create a company of that scale, you need risk capital, entrepreneurial ambition, and a large number of startups. In other markets, hundreds of firms compete, and one eventually emerges as a dominant player.
So it is not about a single effort—it is about building an ecosystem where many experiments take place, and success emerges from that.
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