Regarding Indian private space sector, In addition to skyroot solid rocket, following are noteworthy
Agnikul is planning to launch semi-cryo kerosene rocket pretty soon. Their engine is 3d printed and use electric pump fed 25kN small engine. Planning to launch 4 clustered engines as first stage and already did suborbital test, with some parachute splash down reusability claims.
Astrobase is recent entrant. With decent funding and former ISRO scientists as core team, developing 800kN FFCS methalox engine. FFCS is called holy grail of liquid engines. They have acquired largest metal 3d engine and planning VTVL 1st stage reusability
Also, Pixxel, Skyroot, and Agnikul are targeting orbital data center launches this year for defense applications (which is what the entire ODC story is about). The US NRO already uses India's Pixxel [0] along with Finland's ICEYE (which is now co-manufacturing synthetic aperture sats in India with Agnikul [1]) for hyperspectral scanning.
Edit: can't reply
> But.. why?
Missile Defense and C4ISR [2]. Seconds matter, so most of the newer generation of missile defense systems are experimenting with how to offload compute at the edge to reduce C2 latency.
Most orbital sat startups in the US, China, and India are partially backed by military and intel oriented funds (eg. Starcloud and IQT/In-Q-Tel).
This borders on science fiction. 88,000-and 1-million satellite clusters (as claimed in your link) are hard to take seriously, especially with the possibility of Kessler Syndrome. Also:
1. How do you cool your chips? Vacuum is a thermal insulator, so radiators are required to remove heat. nVidia (or even ASICs) require much and specialised cooling.
2. How does one radiation harden a H100?
3. I'm also seeing where TCO for these are 78x their terrestrial equivalents [0]. Is that financial sustainable?
And there still remain issues with power supply, regulations, and bandwidth. This feels more like a thought experiment rather than an actual serious engineering or business case.
The projections are questionable, but this is something the US and China are experimenting with as well.
1 and 2 are still open questions, but these are not aimed to be commercial grade DCs - this is basically edge compute (think a handful of racks). 3 is not a problem for defense usecases. (EDIT: Discussion here seems to point out that data OP is using might be flawed [1]).
Ignoring the fact that just about every orbital data center startup in the US is funded by IQT and China's CMF has been doing something similar is bad from a defense perspective.
Based on dealflow, these aren't being targeted for consumer usecases in the short-term and whoever has been saying that is misleading.
> especially with the possibility of Kessler Syndrome...
India, Russia, China, and the US don't care about Kessler Syndrome - they have already launched and deployed ASATs. This also comes after India and China had a near collision in 2024 that was treated as an offensive action [0].
This reminds me of the railgun. Basic math and physics tells us that not only would the (very expensive) barrels wear out very quickly, but that it would have had to be fitted on on a nuclear-powered pocket battlecruiser.
Worse, the technology for firing any meaningful payloads from an electric gun (8" Small Diameter Bomb equivalents, guided, airburst, incendiary) simply does not exist.
Same as with Musk's California Vacuum Tunnel (which diverted attention from passenger rail). And his Neuralink. In the 1980s, it was nuclear pumped space-based lasers and Soviet particle beam weapons.
All of the above can be debunked with 2 years undergrad physics and a Casio calculator. Yet they were still taken seriously by high-level politicians and business, some of whom were deeply connected with the military-industrial complex.
People have shrugging of questions like 1 and 2, only for 3 to hit them very hard. But we will see if they can launch 600 of these satellites as they claim.
Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
- ed, disclosure: You seem to have edited your response whilst I was typing mine, adding in valuable links. Thanks!
> Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
In the real world, "physics" is not necessarily the gating factor. There is a major concern about the environmental footprint of terrestrial data centers, to the point where major U.S. states are enacting moratoriums: https://www.governor.ny.gov/news/first-statewide-moratorium-.... These legal and social roadblocks must be accounted for in analyzing the viability of orbital data centers.
If the "physics" tells you that your satellite cannot radiate heat away from your nVidia GPU cluster because each H100 needs 1.1 meter square of radiator, then opinions do not matter. The same applies to power supply and bandwidth.
> Another way to think about it: An SSPP spacecraft with a 60-meter-by-60-meter surface area made using today’s space PV-cell technology would cost $36 million and weigh nearly 9,000 pounds, or almost as much as a Ford F-450 truck. With the ultra-lightweight PV-cell technology Atwater envisions, it would cost just $450,000 and weigh about 300 pounds, or about as much as an IKEA three-seat sofa
That’s megawatt-level solar power under 5 tons using today’s leading edge technology. Starship super heavy can launch 100 tons into LEO.
As to bandwidth, Starlink V3 backhaul capacity is 1 terabit. Microwave radio frequencies have an insane amount of bandwidth.
The cost of replacement is exorbitant for commercial usecases, but is acceptable for defense usecases.
The issue is too many people are looking at the commercial usecase while ignoring the defense usecase that is what is actually driving the conversation and dealflow in this segment.
First, it assumes the radiator is at the same temperature as the GPU. But radiators become dramatically more effective as temperature increases, with radiated power increasing as the fourth power of absolute temperature. So a heat pump that drives the radiator at higher temperature could make the radiator far smaller. More power would be required (and the radiator would have to radiate this energy too) but the radiator could become much smaller.
The other problem is assuming the radiator is intercepting sunlight. But it can be shaded by reflective films or kept edge-on to the Sun.
> Ok, there are at least two bad assumptions there.
>
> First, it assumes the radiator is at the same temperature as the GPU. But radiators become dramatically more effective as temperature increases, with radiated power increasing as the fourth power of absolute temperature. So a heat pump that drives the radiator at higher temperature could make the radiator far smaller.
Carnot's theorem and refridgeration cycles rear their head. Your heat pump still needs power to pump heat uphill., negating any savings from a smaller radiator. And what happens when you shrink a radiator? It becomes a high temperature radiator, meaning the GPU must operate outside its operational tmperature of about 70 degrees C. So small radiator = big pump + extra solar panels and batteries + dead GPU
Also, how do you deal with the added cost and complexity for the solar tracking mechanisms for the "edge-on-to-the-Sun" radiator?
> Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
Don't worry, most of the people online didn't get the memo on this.
One of the major selling points of orbital compute is power supply - more specifically, it turns out that, compared to beaming power from space, it's projected to be cheaper to move compute upwell instead - atmosphere losses for beamed power are just too big. Of course this doesn't matter if you can get cheap, clean power from elsewhere (e.g. nuclear).
This is in general data center case. Here, GP says the motivation is reducing C2 RTT, which makes sense for military applications.
My concern is more in the realms of cooling. I know there's the potential for lots of 'free' energy up there, but how do you then ensure your space-based array of GPU farms bleed all of the resultant heat?
From a Defense perspective, it's acceptable if multiple ODC fails and you have to re-launch another one. This is why these are being treated as part of a mesh. These aren't supposed to be a commercial DC and are intended to be a mesh of multiple racks in orbit.
The fact that the US, China, Russia, and India have already deployed ASATs means a Kessler effect if a question of when and not if.
We could. The usual stumbling block is how to ship fissile material upwell without the risk of a launch failure spreading highly radioactive material over several countries.
> What's the power loss from beaming down power?
I think it's about 10% from atmosphere alone, but you have to add losses from other components in the system, including light -> current -> RF and RF -> current legs, and I've seen estimates ranging from 15% to 40% efficiency end to end; this random article includes breakdown with estimates, that multiplies down to 37.5% efficiency end-to-end.
Also to spell out another non-obvious aspect of beamed power, it turns out that it's not the efficiency that's the limiting factor per se, but land - you can improve efficiency by building larger rectennas, but it gets very expensive very quickly once you consider paying for land under them.
There is just so much that can go wrong with rocket launches if you do cursory reading about these things. A few random examples: The lowest stage cant just be "turned down" or modulated because they work by burning an inner solid rubber lining that's like an annular cylinder. The first three stages are roughly doing the job sequence:
`lift off the ground -> reach target altitude -> reach target orbital velocity` and each stage is modulated for atmospheric pressure, gravity. Another limit is you can't really design it for a human in the middle(like a jet plane), so the rocket's computer needs to do everything, and when the rocket's pitch or yaw or roll(in a manner of speaking) go off beyond a nominal range its game over.
ISRO has a very good track record of launching rockets with solid state engines. I do wonder if almost all of their expertise was used for the first three stages(and they are not 3d printed)? And how much more difficult it is to make the last stage as compared to the first three, which as I understand, was the stage designed and tested by skyroot itself(manufactured by Wipro 3D).
- is there a place that you recommend where they teach you how rockets work, what is involved in building one, the math and physics behind it, materials required etc etc?
I think an important thing here is that the company is almost 8 years old. Which, is not old for a defense tech manufacturer, but does give them leeway to develop and test
And with $160MM in funding at a $1.1B valuation? I don't know about their debt, but to get to LEO in 8 years on that little money is extremely impressive.
> And with $160MM in funding at a $1.1B valuation? I don't know about their debt, but to get to LEO in 8 years on that little money is extremely impressive.
Interestingly that's $5 million less than the the movie Interstellar cost to make.
Indian VC's don't really have the same appetite for deep tech as compared to America/Europe. R&D within Indian Enterprises is significantly less as compared to its peers.
From what I know, its partially because of how taxation structures incentivize research as R&D tax breaks or similar don't particularly exist in India
All of this makes founders more likely to move abroad where such research is more valued which makes even less Indian deep tech startups and successes exist. This creates a vicious cycle.
I would also consider that Indian VC scene as compared to America undervalues quite decently even for B2B or even supposing identical companies and even then, Sequoia and some other American VC firms are still the most valued and I feel as if that given their expertise and contacts (other companies that the VC's have invested in being in America), there would be a slight push towards Europe/America in general. Another argument could very well be that in India CS engineer labour costs much less which is honestly some of the largest expertise for any company.
Though Indian VC scene is thriving and Bangalore is interesting but still Silicon valley is different.
There was a blog post which talked about VC dynamics and VC's value your product not on how much the real value they really see in the project is but rather on how much money you would require. So ironically, projects which require larger budgets/funds for researching, larger salaries to work would then have larger valuations.
Thank you for sharing that perspective; I'm from Eastern Europe and have had many Indian colleagues over the years (both in the EU and working remotely). I always wondered, given the super deep talent pool and many founders originally from India, why we don't see that many Indian companies on the global stage.
I guess Eastern Europe is a bit similar (in the fact that it had a brain drain; although maybe less so since my country joined the EU), but also have a unique challenges, i.e., the EU market is fragmented and the companies need to break into a market by market.
They are charging around $14-15k per kg (~$5M per launch with a max payload of 350kg) but are also offering an additional 30% discount to make them cost competitive against ISRO.
Somewhat, but rocket engineering has some upward cost pressures that offset the savings from being in India: expertise is expensive even adjusting for the cost of labor (many staff are likely competing on salary with the rest of the world--rocket engineers/scientists are in high demand with lots of likely sponsors for immigration); aerospace materials/fabrication have a pretty global supply and patent chain even given how big and diverse India's industrial base is; safety and engineering tolerances are incentivized to meet global standards (many prospective launch/payload customers and investors are international), and so on.
I'm no expert, but I suspect that even if you apply a generous discount for being in India, Skyroot's economics are still quite impressive.
My cousin is an aerospace engineer and works in ISRO (Indian space research organization), its impressive what they are doing but I'd like to chime in on a few things.
I am unsure about private salaries but in govt. jobs, because it follows a rigid structure, the salary is still lower than what you might expect and is around the mark of 20-25 thousand dollars per year. It's similar to administrative services or depending on the position, equal to teachers/professors .
I have heard my cousin say that its hard for people to move outside because for example SpaceX/NASA couldn't hire non-American person because of laws and regulations due to security purposes.
From what I know, my cousin actually got some job offers when he had gone to give a speech recently from Management companies
20-25k$ in India isn't bad but strictly speaking, Computer science earns comparable in India at the same level.
The value of the job is mostly in govt rather than private and the benefit of it is that the work is much less stressful rather than private companies stress and just like how NASA has some prestige attached to it in America, same way goes for ISRO in India.
I suspect a lot of the value from the job comes from the engineers being people who drew up dreaming of rockets and playing Kerbal Space Program as in other countries. Average engineer quality might also be higher filtering for that rather than people who chose their engineering subfield based on salary and emigration prospects and parental expectations..
> rocket engineers/scientists are in high demand with lots of likely sponsors for immigration
I wouldn't be too sure about the immigration part, when even a software engineer hire for a defence/defence adjacent job requires jumping through a number of bureaucratic hoops of security clearances. Even the companies with deep pockets don't always get the best people in the world -- they just get the best people that HR can actually hire.
That's often true, but less true than it was a decade ago. Private, commercial space companies are a lot more numerous now. Sure, most of them have military contracts/oversight as well, but there are more opportunities with them that don't require military/government certification/authorization of immigrant hires than there were previously.
Also, there are plenty of space companies that aren't in the US/UK/China who are hiring (and more willing to work with non-domestic employees since they're playing catch-up), and plenty of companies in US/UK/China who employ contractors that aren't subject to the same hiring restrictions as the first-party/defense-contracted company.
There are a lot more specialized/high-expertise roles here than the ones critical to a nation's space program (or fungible with making weapons). Random examples off the top of my head include crew/life support expertise, launch facility engineering, LEO consumer telecommunications, and more. Space hasn't been fully commodified/detached from government interests--not by a long suborbital burn--but it's moving that direction enough to thaw out the ability to immigrate for work a bit.
What are you basing this on? AFAIK space is still exactly the same, at least in the US. Rockets fall under ITAR and so all hiring at companies working in rocketry is generally going to fall under those regulations which exclude everybody except US citizens/permanent residents. ITAR covers anybody who might come in contact with controlled technologies, so even a e.g. janitor's going to hired with ITAR compliance in mind.
Consider how many rocket development efforts squandered 10X to 100X the money, and >8 years, without making it to orbit.
Using solid fuel for their first 3 stages also makes it far easier. I'd take that as evidence of their management wisely picking a good shape for the org's learning curve. Vs. chasing the long-odds bragging rights & likely heartbreaks of a liquid-fuels-only version 1.0.
I can't tell if this is sarcasm, trolling, or delusion, so congrats, I guess.
SpaceX might fail for any number of reasons in the next ten years, but I would bet a lot of money that it won't be because they got outcompeted by Skyroot.
Other than whats publicly available, an interesting thought about this is how they were able to launch and create something within the highly corrupted political system. Every launch, stage and approval probably required sometype of bribe (even with the current governments focus on deep tech and scientific development)
Extremely strong performance from India’s Skyroot with their Vikram-1 rocket. I can say that many in the space industry are looking for new launch capacity to LEO.
Does anyone know what they're using for telemetry? Over the launch pad you have a UHF link, but that offers infrequent availability after launch.
If I were launching my first orbital vehicle and I didn't have a hyper developed space program already, I would want to equip it with something like Starlink so I would be able to communicate with it even when it wasn't in range of my ground station(s).
The first, second and third stages all being solid rockets also means India now has a global-range ICBM, with only a little bit of modification needed to make it storable in a silo. Privately developed, but I would be astonished if the Indian military isn't well aware of this new capability.
India has had the ability to reach LEO and beyond for a while now. So bringing down a nuke anywhere on the planet wouldn't be that difficult for them. That goes for any country that has LEO launch capabilities. Of course miniaturization of the nuclear payload is another matter.
Do you need to be able to strike at a moment's notice?
For a proper MAD-based nuclear deterrence, yes, you want to be able to launch a massive retaliation while your enemies' missiles are still in the air. Submarine-launched missiles also require stable storage. But having first-strike capabilities, the ability to wipe out any city in the world in return for a few weeks' planning, seems like something militaries would find valuable.
Right, but see the details for estimated range and the map. Not that India has any foreseeable need to nuke Argentina but it's not in range. It's entirely possible the public data is wrong and the Agni VI has a global range.
But by definition if you can put something into a 350x350 km low earth orbit (something like 7800m/s total delta V) you could also deliver a re-entering payload from your launch site to any other spot on earth, within the limitations of the inclination you're launching to.
Multiple sources think that the real range is an ICBM level. And the Indian government purposely limits it's range. No strategic reason to communicate a larger range than needed and why have an headline that reads, "India develops capability to nuke Europe or US"?
India has developed ASAT, which is arguably more complicated that ICBM, agni series, they developed. India routinely understates ranges and appear non threatening. Agni5 and 6 are genuine ICBM, and with little tuning could reach anywhere in the world. India's bureaucracy and MEA is beset with gandhian mindset who try to avoid confrontations and minimise belligerence, opposite of PRC wolf warriors I guess.
> India's bureaucracy and MEA is beset with gandhian mindset who try to avoid confrontations and minimise belligerence, opposite of PRC wolf warriors I guess.
It isn't because of some purported Gandhian mindset. It's becuase India is in a pacing conflict with China and Pakistan, whereas China is in one with the US and historically the USSR. Assuming the Chagos Archipelago dispute gets resolved in the next decade (India and France backs it's return to Mauritius because Mauritius' police and military leadership are under direct Indian control [0] but the US prefers Chagos remaining under British control because we are closer aligned), India has no need to explicitly publicize ICBM capabilities that extend beyond China or Turkiye.
Additionally, publicly stating India has ICBM capabilities makes it harder to land transnational mining deals [1] because then discussions with Australia, Brazil, Canada, etc adopt a nuclear proliferation dimension as well as placing a target on India's private sector because of SpaceTech and DefenseTech's dual use implications.
I presume they're thinking any potential adversaries have functioning intelligence agencies, so something as public as a launch is sufficient. No need to come out and explicitly state it.
If I, some rando on the internet, can theorize "that sure looks like it could be turned into a storable icbm that could deliver a nuke to hawaii or Tierra del Fuego or anywhere else on the globe" can make that guess, then any other major world power is likely far ahead of me in analysis.
Also well known that having the institutional knowledge and technical capability to build or adapt something in a fairly short time frame is almost as good as having the thing ready to go.
> Also well known that having the institutional knowledge and technical capability to build or adapt something in a fairly short time frame is almost as good as having the thing ready to go.
This is similar to how Japan doesn't have nuclear weapons.
> I presume they're thinking any potential adversaries have functioning intelligence agencies, so something as public as a launch is sufficient. No need to come out and explicitly state it.
It’s a strange place. They’re building out expressways and railways at a breathtaking pace (something like an entire Switzerland’s worth of new track every year), are simultaneously building out multiple nuclear reactors, exports and manufacturing are shooting up, but the cities still look like shit.
India thrives in high tech sectors that are ironically export controlled by the rest of the world. That’s the primary reason the talent in those domains stays back.
As for the rest of India, you can largely find the root causes of problems by tracing adverse selection effects among the elites that do remain, massive, conflicting vested interests and decades of horrible, incompetent policymaking.
4 stages is certainly a lot more than most rockets, but most rockets don’t use solid rocket stages. Solid rocket motors are generally much more reliable/ simpler than liquid fueled stages, but they can’t be throttled or turned off early which makes it hard to achieve precise orbits. My guess is the extra stages allow for better control by carefully choosing when to light the next stage. The scout family of rockets are also 4 stage solid rockets and probably a good comparison.
Solid motors are simpler, but I wouldn't say they're more reliable. It was the solid booster failure that caused the Challenger disaster, and solid booster failures that have caused ULA's Vulcan Centaur rocket to be grounded. As you say, solids can't be throttled or turned off easily. They also can't be test fired. Yes, you can static fire a solid rocket and reuse the housing/nozzle/etc, but solids often fail due to imperfections in the propellant. Pockets of air or fractures in the propellant can cause a sudden increase in propellant surface area, which then generates more pressure, potentially blowing up the booster. With a liquid rocket, the engine can shut down if there's an anomaly. But with a solid, there's no option but to let the reaction continue.
There's also the issue that a solid booster must be "fueled" before it reaches the pad, meaning you have ground crew working around a large quantity of explosive material. A Brazilian solid rocket exploded on the launch pad, killing 21 people.[1] Liquid rockets can be made inert until everyone is far away, then loaded with propellant.
A big advantage of solid rockets is that they can be stored for long periods and quickly launched. This is handy for use cases like ICBMs, but not particularly important for commercial launches.
Rockets are usually two-staged + satellites. The booster take it to outside of the atmosphere, then the upper stage puts it into a ballistic trajectory, and the payload does the circularization burn 45 minutes or so after the liftoff at the peak of the parabola.
Above is the basic semantics, and it can be further optimized, such as by extending battery power for the second stage to use it for circularization, inserting a single purpose satellite-like pusher device above the responsibility boundary at the top of second stage and payload satellite and calling it the third stage, or just adding actual third stage above second stage, etc.
Adding more and more stages improve performance per Konstantin Tsiolkovsky's rocket equation, but it'll add risk factors and also obviously add more dead weights in electronics and engines and support equipment, so 2-3 stages is usually the good balance between performance and risk/costs. You can have as many stages as you want if you think you can handle it.
I think that only applies to liquid fueled rockets. At a minimum the Scout family of rockets (USA) and the Lambda 4s (Japan) both use 4 stages. That is what I was trying to say above. The sibling comment also points out that you at least need a third stage to circularize the orbit, since you can't re-light solid rocket motors. I'm not exactly clear on why its 4 and not 3, but that seems to be the standard with solid fueled rockets.
I think it's for maneuvering. At least L-4S seemed to have had 3rd for the pitchover and 4th for the apogee kick. The first two were spin stabilized and unguided for political reasons. "Payload" stages built more like satellites are better suited for precise guidance.
(ISAS side of Japanese space programs is chock full of political BS, everything from the pencil rocket that continued on from IJN rocket researches to the "unguided" L-4S to the LUNAR-A probe with diameter of approximately 152-155mm to one-man laptop launchable Epsilon LV concept focusing on "civilian low-cost rapid launch demands")
It's three solid rocket boosters stacked on top of each other and a very tiny liquid fueled engine on the 4th stage. I would be interested in what the delta/v stats/capability of the 4th stage booster are with 350 kg payload.
A partially empty stage wastes mass on propellant tanks sized for the full load. The mathematical ideal would be an infinite number of infinitesimally small stages.
I have an AI generated podcast that tries to unearth some of the negative spin that develops around these amazing achievements. No surprise there was a spike in misinformation this week and I’m sure there will be more to come.
It's so sad that the Modi clique controls India. If India could become a real democracy, it could be competitive in the long run against China, because assuming similar quality and costs, people in democracies would much rather support a democracy than sinomarxist China or crazy-oligarch orange king country. But with Modi in charge, none of that is possible. Old men really need to leave politics, they just cause too many problems in general.
I haven't followed Indian politics in a while, but I don't understand the "real democracy" comment. Can you elaborate on this? Or is it because Modi won three elections in a row?
Regarding Indian private space sector, In addition to skyroot solid rocket, following are noteworthy
Agnikul is planning to launch semi-cryo kerosene rocket pretty soon. Their engine is 3d printed and use electric pump fed 25kN small engine. Planning to launch 4 clustered engines as first stage and already did suborbital test, with some parachute splash down reusability claims.
Astrobase is recent entrant. With decent funding and former ISRO scientists as core team, developing 800kN FFCS methalox engine. FFCS is called holy grail of liquid engines. They have acquired largest metal 3d engine and planning VTVL 1st stage reusability
Wow, being able to develop an FFCS engine would be a huge feather in the cap for the Indian aerospace industry.
Also, Pixxel, Skyroot, and Agnikul are targeting orbital data center launches this year for defense applications (which is what the entire ODC story is about). The US NRO already uses India's Pixxel [0] along with Finland's ICEYE (which is now co-manufacturing synthetic aperture sats in India with Agnikul [1]) for hyperspectral scanning.
Edit: can't reply
> But.. why?
Missile Defense and C4ISR [2]. Seconds matter, so most of the newer generation of missile defense systems are experimenting with how to offload compute at the edge to reduce C2 latency.
Most orbital sat startups in the US, China, and India are partially backed by military and intel oriented funds (eg. Starcloud and IQT/In-Q-Tel).
-----
[0] - https://www.nro.gov/news-media-featured-stories/news-media-p...
[1] - https://www.livemint.com/companies/news/agnikul-cosmos-iceye...
[2] - https://idsa.in/wp-content/uploads/2026/01/book-MISSION-SUDA...
This borders on science fiction. 88,000-and 1-million satellite clusters (as claimed in your link) are hard to take seriously, especially with the possibility of Kessler Syndrome. Also:
1. How do you cool your chips? Vacuum is a thermal insulator, so radiators are required to remove heat. nVidia (or even ASICs) require much and specialised cooling.
2. How does one radiation harden a H100?
3. I'm also seeing where TCO for these are 78x their terrestrial equivalents [0]. Is that financial sustainable?
And there still remain issues with power supply, regulations, and bandwidth. This feels more like a thought experiment rather than an actual serious engineering or business case.
[0] https://www.abiresearch.com/blog/data-centers-in-space
The projections are questionable, but this is something the US and China are experimenting with as well.
1 and 2 are still open questions, but these are not aimed to be commercial grade DCs - this is basically edge compute (think a handful of racks). 3 is not a problem for defense usecases. (EDIT: Discussion here seems to point out that data OP is using might be flawed [1]).
Ignoring the fact that just about every orbital data center startup in the US is funded by IQT and China's CMF has been doing something similar is bad from a defense perspective.
Based on dealflow, these aren't being targeted for consumer usecases in the short-term and whoever has been saying that is misleading.
> especially with the possibility of Kessler Syndrome...
India, Russia, China, and the US don't care about Kessler Syndrome - they have already launched and deployed ASATs. This also comes after India and China had a near collision in 2024 that was treated as an offensive action [0].
[0] - https://www.bloomberg.com/news/articles/2025-09-22/india-pla...
[1] - https://news.ycombinator.com/item?id=49039873
This reminds me of the railgun. Basic math and physics tells us that not only would the (very expensive) barrels wear out very quickly, but that it would have had to be fitted on on a nuclear-powered pocket battlecruiser.
Worse, the technology for firing any meaningful payloads from an electric gun (8" Small Diameter Bomb equivalents, guided, airburst, incendiary) simply does not exist.
Same as with Musk's California Vacuum Tunnel (which diverted attention from passenger rail). And his Neuralink. In the 1980s, it was nuclear pumped space-based lasers and Soviet particle beam weapons.
All of the above can be debunked with 2 years undergrad physics and a Casio calculator. Yet they were still taken seriously by high-level politicians and business, some of whom were deeply connected with the military-industrial complex.
People have shrugging of questions like 1 and 2, only for 3 to hit them very hard. But we will see if they can launch 600 of these satellites as they claim.
Soviets definitely experimented with airborne CO2 lasers.
As raynier and pfdietz pointed out [0], the assumptions you are using aren't necessarily correct.
[0] - https://news.ycombinator.com/item?id=49039873
Mein Gott, you're not just making this up ( https://www.datacenterdynamics.com/en/news/neevcloud-and-agn... ).
But.. why?
Musk bandwagon-hopping? Investor bamboozlery? (Same diff?)
Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
- ed, disclosure: You seem to have edited your response whilst I was typing mine, adding in valuable links. Thanks!
> Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
In the real world, "physics" is not necessarily the gating factor. There is a major concern about the environmental footprint of terrestrial data centers, to the point where major U.S. states are enacting moratoriums: https://www.governor.ny.gov/news/first-statewide-moratorium-.... These legal and social roadblocks must be accounted for in analyzing the viability of orbital data centers.
If the "physics" tells you that your satellite cannot radiate heat away from your nVidia GPU cluster because each H100 needs 1.1 meter square of radiator, then opinions do not matter. The same applies to power supply and bandwidth.
The radiator is much more efficient than the solar panels (for obvious reasons), so that’s not the limiting factor.
As to power, Caltech is already at 2-3 pounds per square meter: https://magazine.caltech.edu/post/sspp-space-solar-power-pro...
> Another way to think about it: An SSPP spacecraft with a 60-meter-by-60-meter surface area made using today’s space PV-cell technology would cost $36 million and weigh nearly 9,000 pounds, or almost as much as a Ford F-450 truck. With the ultra-lightweight PV-cell technology Atwater envisions, it would cost just $450,000 and weigh about 300 pounds, or about as much as an IKEA three-seat sofa
That’s megawatt-level solar power under 5 tons using today’s leading edge technology. Starship super heavy can launch 100 tons into LEO.
As to bandwidth, Starlink V3 backhaul capacity is 1 terabit. Microwave radio frequencies have an insane amount of bandwidth.
I have a lot of respect for Atwater but I'm pretty sure a lot of people at Caltech think this is donor driven research.
What are the assumptions behind that 1.1 m^2 figure?
OP is quoting Mikhail Klassen at Planet Labs [0].
The cost of replacement is exorbitant for commercial usecases, but is acceptable for defense usecases.
The issue is too many people are looking at the commercial usecase while ignoring the defense usecase that is what is actually driving the conversation and dealflow in this segment.
[0] - https://www.mikhailklassen.com/posts/orbital-data-centers/or...
Ok, there are at least two bad assumptions there.
First, it assumes the radiator is at the same temperature as the GPU. But radiators become dramatically more effective as temperature increases, with radiated power increasing as the fourth power of absolute temperature. So a heat pump that drives the radiator at higher temperature could make the radiator far smaller. More power would be required (and the radiator would have to radiate this energy too) but the radiator could become much smaller.
The other problem is assuming the radiator is intercepting sunlight. But it can be shaded by reflective films or kept edge-on to the Sun.
> Ok, there are at least two bad assumptions there. > > First, it assumes the radiator is at the same temperature as the GPU. But radiators become dramatically more effective as temperature increases, with radiated power increasing as the fourth power of absolute temperature. So a heat pump that drives the radiator at higher temperature could make the radiator far smaller.
Carnot's theorem and refridgeration cycles rear their head. Your heat pump still needs power to pump heat uphill., negating any savings from a smaller radiator. And what happens when you shrink a radiator? It becomes a high temperature radiator, meaning the GPU must operate outside its operational tmperature of about 70 degrees C. So small radiator = big pump + extra solar panels and batteries + dead GPU
Also, how do you deal with the added cost and complexity for the solar tracking mechanisms for the "edge-on-to-the-Sun" radiator?
> Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?
Don't worry, most of the people online didn't get the memo on this.
One of the major selling points of orbital compute is power supply - more specifically, it turns out that, compared to beaming power from space, it's projected to be cheaper to move compute upwell instead - atmosphere losses for beamed power are just too big. Of course this doesn't matter if you can get cheap, clean power from elsewhere (e.g. nuclear).
This is in general data center case. Here, GP says the motivation is reducing C2 RTT, which makes sense for military applications.
My concern is more in the realms of cooling. I know there's the potential for lots of 'free' energy up there, but how do you then ensure your space-based array of GPU farms bleed all of the resultant heat?
From a Defense perspective, it's acceptable if multiple ODC fails and you have to re-launch another one. This is why these are being treated as part of a mesh. These aren't supposed to be a commercial DC and are intended to be a mesh of multiple racks in orbit.
The fact that the US, China, Russia, and India have already deployed ASATs means a Kessler effect if a question of when and not if.
Could we have giant nuclear reactors in space? What's the power loss from beaming down power?
> Could we have giant nuclear reactors in space?
We could. The usual stumbling block is how to ship fissile material upwell without the risk of a launch failure spreading highly radioactive material over several countries.
> What's the power loss from beaming down power?
I think it's about 10% from atmosphere alone, but you have to add losses from other components in the system, including light -> current -> RF and RF -> current legs, and I've seen estimates ranging from 15% to 40% efficiency end to end; this random article includes breakdown with estimates, that multiplies down to 37.5% efficiency end-to-end.
https://www.sciencedirect.com/topics/earth-and-planetary-sci...
EDIT:
This system design gives 7-14% end-to-end efficiency: https://arxiv.org/pdf/2206.08373
EDIT2:
Also to spell out another non-obvious aspect of beamed power, it turns out that it's not the efficiency that's the limiting factor per se, but land - you can improve efficiency by building larger rectennas, but it gets very expensive very quickly once you consider paying for land under them.
There is just so much that can go wrong with rocket launches if you do cursory reading about these things. A few random examples: The lowest stage cant just be "turned down" or modulated because they work by burning an inner solid rubber lining that's like an annular cylinder. The first three stages are roughly doing the job sequence: `lift off the ground -> reach target altitude -> reach target orbital velocity` and each stage is modulated for atmospheric pressure, gravity. Another limit is you can't really design it for a human in the middle(like a jet plane), so the rocket's computer needs to do everything, and when the rocket's pitch or yaw or roll(in a manner of speaking) go off beyond a nominal range its game over.
ISRO has a very good track record of launching rockets with solid state engines. I do wonder if almost all of their expertise was used for the first three stages(and they are not 3d printed)? And how much more difficult it is to make the last stage as compared to the first three, which as I understand, was the stage designed and tested by skyroot itself(manufactured by Wipro 3D).
- you seem to know what you are talking about
- is there a place that you recommend where they teach you how rockets work, what is involved in building one, the math and physics behind it, materials required etc etc?
Kerbal Space Program
Unironically that is a great teach of the basics
I think an important thing here is that the company is almost 8 years old. Which, is not old for a defense tech manufacturer, but does give them leeway to develop and test
Spontaneous rapid disassembly is common in this field.
And with $160MM in funding at a $1.1B valuation? I don't know about their debt, but to get to LEO in 8 years on that little money is extremely impressive.
> And with $160MM in funding at a $1.1B valuation? I don't know about their debt, but to get to LEO in 8 years on that little money is extremely impressive.
Interestingly that's $5 million less than the the movie Interstellar cost to make.
It’s interesting that this is less funding/valuation than hundreds of other random B2B Series C/D companies that may not even exist in 5 years.
No point, just perspective.
Indian VC's don't really have the same appetite for deep tech as compared to America/Europe. R&D within Indian Enterprises is significantly less as compared to its peers.
From what I know, its partially because of how taxation structures incentivize research as R&D tax breaks or similar don't particularly exist in India
All of this makes founders more likely to move abroad where such research is more valued which makes even less Indian deep tech startups and successes exist. This creates a vicious cycle.
I would also consider that Indian VC scene as compared to America undervalues quite decently even for B2B or even supposing identical companies and even then, Sequoia and some other American VC firms are still the most valued and I feel as if that given their expertise and contacts (other companies that the VC's have invested in being in America), there would be a slight push towards Europe/America in general. Another argument could very well be that in India CS engineer labour costs much less which is honestly some of the largest expertise for any company.
Though Indian VC scene is thriving and Bangalore is interesting but still Silicon valley is different.
There was a blog post which talked about VC dynamics and VC's value your product not on how much the real value they really see in the project is but rather on how much money you would require. So ironically, projects which require larger budgets/funds for researching, larger salaries to work would then have larger valuations.
Thank you for sharing that perspective; I'm from Eastern Europe and have had many Indian colleagues over the years (both in the EU and working remotely). I always wondered, given the super deep talent pool and many founders originally from India, why we don't see that many Indian companies on the global stage.
I guess Eastern Europe is a bit similar (in the fact that it had a brain drain; although maybe less so since my country joined the EU), but also have a unique challenges, i.e., the EU market is fragmented and the companies need to break into a market by market.
I wonder what their cost-per-launch will end up being?
Can they compete with reusable American rockets for $/kg by just building disposable but very cheap rockets?
After all, plenty of other disposable things have outcompeted non disposable versions... Diapers... Pens... Lighters... Vapes...
They are charging around $14-15k per kg (~$5M per launch with a max payload of 350kg) but are also offering an additional 30% discount to make them cost competitive against ISRO.
If you do all the work in India, you have low materials costs and low labour costs.
Somewhat, but rocket engineering has some upward cost pressures that offset the savings from being in India: expertise is expensive even adjusting for the cost of labor (many staff are likely competing on salary with the rest of the world--rocket engineers/scientists are in high demand with lots of likely sponsors for immigration); aerospace materials/fabrication have a pretty global supply and patent chain even given how big and diverse India's industrial base is; safety and engineering tolerances are incentivized to meet global standards (many prospective launch/payload customers and investors are international), and so on.
I'm no expert, but I suspect that even if you apply a generous discount for being in India, Skyroot's economics are still quite impressive.
Edits: clarity
Rocketry is tightly controlled by ITAR, so mobility is lower than you'd expect for a high value field.
And MTCR
My cousin is an aerospace engineer and works in ISRO (Indian space research organization), its impressive what they are doing but I'd like to chime in on a few things.
I am unsure about private salaries but in govt. jobs, because it follows a rigid structure, the salary is still lower than what you might expect and is around the mark of 20-25 thousand dollars per year. It's similar to administrative services or depending on the position, equal to teachers/professors .
I have heard my cousin say that its hard for people to move outside because for example SpaceX/NASA couldn't hire non-American person because of laws and regulations due to security purposes.
From what I know, my cousin actually got some job offers when he had gone to give a speech recently from Management companies
20-25k$ in India isn't bad but strictly speaking, Computer science earns comparable in India at the same level.
The value of the job is mostly in govt rather than private and the benefit of it is that the work is much less stressful rather than private companies stress and just like how NASA has some prestige attached to it in America, same way goes for ISRO in India.
I suspect a lot of the value from the job comes from the engineers being people who drew up dreaming of rockets and playing Kerbal Space Program as in other countries. Average engineer quality might also be higher filtering for that rather than people who chose their engineering subfield based on salary and emigration prospects and parental expectations..
> rocket engineers/scientists are in high demand with lots of likely sponsors for immigration
I wouldn't be too sure about the immigration part, when even a software engineer hire for a defence/defence adjacent job requires jumping through a number of bureaucratic hoops of security clearances. Even the companies with deep pockets don't always get the best people in the world -- they just get the best people that HR can actually hire.
That's often true, but less true than it was a decade ago. Private, commercial space companies are a lot more numerous now. Sure, most of them have military contracts/oversight as well, but there are more opportunities with them that don't require military/government certification/authorization of immigrant hires than there were previously.
Also, there are plenty of space companies that aren't in the US/UK/China who are hiring (and more willing to work with non-domestic employees since they're playing catch-up), and plenty of companies in US/UK/China who employ contractors that aren't subject to the same hiring restrictions as the first-party/defense-contracted company.
There are a lot more specialized/high-expertise roles here than the ones critical to a nation's space program (or fungible with making weapons). Random examples off the top of my head include crew/life support expertise, launch facility engineering, LEO consumer telecommunications, and more. Space hasn't been fully commodified/detached from government interests--not by a long suborbital burn--but it's moving that direction enough to thaw out the ability to immigrate for work a bit.
What are you basing this on? AFAIK space is still exactly the same, at least in the US. Rockets fall under ITAR and so all hiring at companies working in rocketry is generally going to fall under those regulations which exclude everybody except US citizens/permanent residents. ITAR covers anybody who might come in contact with controlled technologies, so even a e.g. janitor's going to hired with ITAR compliance in mind.
>"AFAIK space is still exactly the same, at least in the US." - I believe he is talking about countries other than the US
True, but:
Consider how many rocket development efforts squandered 10X to 100X the money, and >8 years, without making it to orbit.
Using solid fuel for their first 3 stages also makes it far easier. I'd take that as evidence of their management wisely picking a good shape for the org's learning curve. Vs. chasing the long-odds bragging rights & likely heartbreaks of a liquid-fuels-only version 1.0.
you can imagine if they bother cracking landing back to re-use, it's KO for spacex
I can't tell if this is sarcasm, trolling, or delusion, so congrats, I guess.
SpaceX might fail for any number of reasons in the next ten years, but I would bet a lot of money that it won't be because they got outcompeted by Skyroot.
Other than whats publicly available, an interesting thought about this is how they were able to launch and create something within the highly corrupted political system. Every launch, stage and approval probably required sometype of bribe (even with the current governments focus on deep tech and scientific development)
Only the third country to achieve this. Kudos.
There's another startup trying reusable rockets.
> Only the third country to achieve this.
What do you mean by this?
Probably meant the third country with a private sector capability to launch rockets, US and China being the other two.
There's New Zealand as well with RocketLab
as opposed to New Zealand?
Rocket Lab is a US company, they would not have been able to build what they did without full ITAR and MTCR compliance.
Maybe you need to let them know.
They were founded in NZ by a NZer, they launch from NZ, their employees are NZers. Calling them a US company is equivalent to saying Google is Irish.
https://news.ycombinator.com/item?id=18427351
Design and manufacturing is in the los angeles region aerospace industry cluster.
It's been a US company for the last 13 years.
https://rocketlabcorp.com/updates/rocket-lab-makes-its-defen...
RL incorporated in the USA to gain launch licenses.
They've been an American company for over a decade at this point.
For those interested, just read a great book on this topic: When the Heavens Went on Sale by Ashlee Vance: https://www.goodreads.com/book/show/62050244-when-the-heaven...
It profiles: Astra, Firefly, Planet Labs, and Rocket Lab
this is Skyroot Aerospace
Extremely strong performance from India’s Skyroot with their Vikram-1 rocket. I can say that many in the space industry are looking for new launch capacity to LEO.
Does anyone know what they're using for telemetry? Over the launch pad you have a UHF link, but that offers infrequent availability after launch.
If I were launching my first orbital vehicle and I didn't have a hyper developed space program already, I would want to equip it with something like Starlink so I would be able to communicate with it even when it wasn't in range of my ground station(s).
Quite the achievement, congratulations! I'm really curious to see how things unfold when tens of private companies can launch payloads into LEO.
That's pretty cool. The phrase "3D-printed engine" stuck out to me as neat, too.
Rocket Lab has been printing engines for some time now
https://en.wikipedia.org/wiki/Rutherford_(rocket_engine)
So has SpaceX. It's becoming standard practice these days.
The first, second and third stages all being solid rockets also means India now has a global-range ICBM, with only a little bit of modification needed to make it storable in a silo. Privately developed, but I would be astonished if the Indian military isn't well aware of this new capability.
India has had the ability to reach LEO and beyond for a while now. So bringing down a nuke anywhere on the planet wouldn't be that difficult for them. That goes for any country that has LEO launch capabilities. Of course miniaturization of the nuclear payload is another matter.
Liquid fueled launch vehicles aren't storable/able to be made ready at a moment's notice, unlike solids. Liquid fueled historical artifact:
https://en.wikipedia.org/wiki/SM-65_Atlas
There's a reason all modern silo based (and submarine) ICBMs are solids.
> There's a reason all modern silo based (and submarine) ICBMs are solids.
Believe it or not, here in 2026, this is incorrect!
Those crazy Russians:
https://en.wikipedia.org/wiki/R-29RMU_Sineva
https://en.wikipedia.org/wiki/R-29RMU2_Lajner
UDMH + nitrogen tetroxide.
I would not want to be a Russian submariner. For all sorts of reasons.
Do you need to be able to strike at a moment's notice?
For a proper MAD-based nuclear deterrence, yes, you want to be able to launch a massive retaliation while your enemies' missiles are still in the air. Submarine-launched missiles also require stable storage. But having first-strike capabilities, the ability to wipe out any city in the world in return for a few weeks' planning, seems like something militaries would find valuable.
The mil have had solid propulsion for a while https://en.wikipedia.org/wiki/Agni-VI
Right, but see the details for estimated range and the map. Not that India has any foreseeable need to nuke Argentina but it's not in range. It's entirely possible the public data is wrong and the Agni VI has a global range.
But by definition if you can put something into a 350x350 km low earth orbit (something like 7800m/s total delta V) you could also deliver a re-entering payload from your launch site to any other spot on earth, within the limitations of the inclination you're launching to.
I was under the impression long range missiles aren't much use in global warfare anymore, because they are easy targets for missile defence systems.
Even if your target doesn't have missile defence systems, any ally of theirs along the route can intercept too.
Multiple sources think that the real range is an ICBM level. And the Indian government purposely limits it's range. No strategic reason to communicate a larger range than needed and why have an headline that reads, "India develops capability to nuke Europe or US"?
India has developed ASAT, which is arguably more complicated that ICBM, agni series, they developed. India routinely understates ranges and appear non threatening. Agni5 and 6 are genuine ICBM, and with little tuning could reach anywhere in the world. India's bureaucracy and MEA is beset with gandhian mindset who try to avoid confrontations and minimise belligerence, opposite of PRC wolf warriors I guess.
> India's bureaucracy and MEA is beset with gandhian mindset who try to avoid confrontations and minimise belligerence, opposite of PRC wolf warriors I guess.
It isn't because of some purported Gandhian mindset. It's becuase India is in a pacing conflict with China and Pakistan, whereas China is in one with the US and historically the USSR. Assuming the Chagos Archipelago dispute gets resolved in the next decade (India and France backs it's return to Mauritius because Mauritius' police and military leadership are under direct Indian control [0] but the US prefers Chagos remaining under British control because we are closer aligned), India has no need to explicitly publicize ICBM capabilities that extend beyond China or Turkiye.
Additionally, publicly stating India has ICBM capabilities makes it harder to land transnational mining deals [1] because then discussions with Australia, Brazil, Canada, etc adopt a nuclear proliferation dimension as well as placing a target on India's private sector because of SpaceTech and DefenseTech's dual use implications.
[0] - https://thesecretariat.in/article/inside-raisina-hill-nsa-to...
[1] - https://www.ft.com/content/c5868e2f-8d19-4393-93be-2ad726a63...
I presume they're thinking any potential adversaries have functioning intelligence agencies, so something as public as a launch is sufficient. No need to come out and explicitly state it.
If I, some rando on the internet, can theorize "that sure looks like it could be turned into a storable icbm that could deliver a nuke to hawaii or Tierra del Fuego or anywhere else on the globe" can make that guess, then any other major world power is likely far ahead of me in analysis.
Also well known that having the institutional knowledge and technical capability to build or adapt something in a fairly short time frame is almost as good as having the thing ready to go.
> Also well known that having the institutional knowledge and technical capability to build or adapt something in a fairly short time frame is almost as good as having the thing ready to go.
This is similar to how Japan doesn't have nuclear weapons.
> I presume they're thinking any potential adversaries have functioning intelligence agencies, so something as public as a launch is sufficient. No need to come out and explicitly state it.
Exactly. This is the norm.
India has had ICBMs for decades now.[1]
[1]: https://en.wikipedia.org/wiki/Agni-V?wprov=sfla1
Fantastic news! Always good to see others manage achieve great things.
India's space work often went under the radar. Im glad they're getting the success and attention they deserve.
A small but bright light in an economy where manufacturing jobs are hard to come by (https://archive.ph/Haj8n).
It’s a strange place. They’re building out expressways and railways at a breathtaking pace (something like an entire Switzerland’s worth of new track every year), are simultaneously building out multiple nuclear reactors, exports and manufacturing are shooting up, but the cities still look like shit.
India thrives in high tech sectors that are ironically export controlled by the rest of the world. That’s the primary reason the talent in those domains stays back.
As for the rest of India, you can largely find the root causes of problems by tracing adverse selection effects among the elites that do remain, massive, conflicting vested interests and decades of horrible, incompetent policymaking.
4 stages feels like a lot of added complexity for your first launch. I assume it gives you more performance margin to drop weight/stages more often?
4 stages is certainly a lot more than most rockets, but most rockets don’t use solid rocket stages. Solid rocket motors are generally much more reliable/ simpler than liquid fueled stages, but they can’t be throttled or turned off early which makes it hard to achieve precise orbits. My guess is the extra stages allow for better control by carefully choosing when to light the next stage. The scout family of rockets are also 4 stage solid rockets and probably a good comparison.
Solid motors are simpler, but I wouldn't say they're more reliable. It was the solid booster failure that caused the Challenger disaster, and solid booster failures that have caused ULA's Vulcan Centaur rocket to be grounded. As you say, solids can't be throttled or turned off easily. They also can't be test fired. Yes, you can static fire a solid rocket and reuse the housing/nozzle/etc, but solids often fail due to imperfections in the propellant. Pockets of air or fractures in the propellant can cause a sudden increase in propellant surface area, which then generates more pressure, potentially blowing up the booster. With a liquid rocket, the engine can shut down if there's an anomaly. But with a solid, there's no option but to let the reaction continue.
There's also the issue that a solid booster must be "fueled" before it reaches the pad, meaning you have ground crew working around a large quantity of explosive material. A Brazilian solid rocket exploded on the launch pad, killing 21 people.[1] Liquid rockets can be made inert until everyone is far away, then loaded with propellant.
A big advantage of solid rockets is that they can be stored for long periods and quickly launched. This is handy for use cases like ICBMs, but not particularly important for commercial launches.
1. https://en.wikipedia.org/wiki/VLS-1_V03
Don't you need at least a little thrust ~40 mins later to circularize the orbit?
Obviously solid rockets can't be relit.
Could that be the use of the 4th stage?
Rockets are usually two-staged + satellites. The booster take it to outside of the atmosphere, then the upper stage puts it into a ballistic trajectory, and the payload does the circularization burn 45 minutes or so after the liftoff at the peak of the parabola.
Above is the basic semantics, and it can be further optimized, such as by extending battery power for the second stage to use it for circularization, inserting a single purpose satellite-like pusher device above the responsibility boundary at the top of second stage and payload satellite and calling it the third stage, or just adding actual third stage above second stage, etc.
Adding more and more stages improve performance per Konstantin Tsiolkovsky's rocket equation, but it'll add risk factors and also obviously add more dead weights in electronics and engines and support equipment, so 2-3 stages is usually the good balance between performance and risk/costs. You can have as many stages as you want if you think you can handle it.
> Rockets are usually two-staged + satellites.
I think that only applies to liquid fueled rockets. At a minimum the Scout family of rockets (USA) and the Lambda 4s (Japan) both use 4 stages. That is what I was trying to say above. The sibling comment also points out that you at least need a third stage to circularize the orbit, since you can't re-light solid rocket motors. I'm not exactly clear on why its 4 and not 3, but that seems to be the standard with solid fueled rockets.
I think it's for maneuvering. At least L-4S seemed to have had 3rd for the pitchover and 4th for the apogee kick. The first two were spin stabilized and unguided for political reasons. "Payload" stages built more like satellites are better suited for precise guidance.
(ISAS side of Japanese space programs is chock full of political BS, everything from the pencil rocket that continued on from IJN rocket researches to the "unguided" L-4S to the LUNAR-A probe with diameter of approximately 152-155mm to one-man laptop launchable Epsilon LV concept focusing on "civilian low-cost rapid launch demands")
One example of a typical liquid fueled small third stage would be:
https://en.wikipedia.org/wiki/Fregat
Good point! The final stage being liquid would also give them more control to fix any errors with the orbit.
It's three solid rocket boosters stacked on top of each other and a very tiny liquid fueled engine on the 4th stage. I would be interested in what the delta/v stats/capability of the 4th stage booster are with 350 kg payload.
A partially empty stage wastes mass on propellant tanks sized for the full load. The mathematical ideal would be an infinite number of infinitesimally small stages.
Except you pay the weight for the nozzles on each stage.
That makes there be a mathematically optimal number.
Congratulations!
India desperately needs more r&d and advanced manufacturing. Good for them; congrats to the team
I have an AI generated podcast that tries to unearth some of the negative spin that develops around these amazing achievements. No surprise there was a spike in misinformation this week and I’m sure there will be more to come.
It can be hard when you are blindsided by negativity that seems to come out of nowhere. Hopefully this is helpful to us all https://rss.com/podcasts/the-narrative-networks-podcast/3017...
btw recently discovered this neat website that shows ALL upcoming rocket launches
* https://nextspaceflight.com/launches/details/8033/
* https://nextspaceflight.com/launches/
It's so sad that the Modi clique controls India. If India could become a real democracy, it could be competitive in the long run against China, because assuming similar quality and costs, people in democracies would much rather support a democracy than sinomarxist China or crazy-oligarch orange king country. But with Modi in charge, none of that is possible. Old men really need to leave politics, they just cause too many problems in general.
I haven't followed Indian politics in a while, but I don't understand the "real democracy" comment. Can you elaborate on this? Or is it because Modi won three elections in a row?
Superpower by 2026 it seems
It did become a developed country by 2020 according the original vision.
Vikram-1 is distilled version of Saturn-V
Reminds me of the NYC cartoon too ;)
Very good reminder!