Q&A: How 3D Printing Can Enable On-Demand Space Launches

Indian startup delivers customized rocket engines for fast and cheap space access

5 min read

Left is a rendering of the top of a rocket with the Indian flag on it. Right is a photo of a silver contraption and a larger dark grey hourglass object.

Agnikul's launch vehicle Agnibaan (left), 3-D printed rocket engine Agnilet (background, right) and 3-D printed cryogenic pump (front, right).


The Indian Space Research Organisation (ISRO) has established itself as one of the world's leading national space agencies, with a reputation for frugal innovation and a booming commercial launch operation.

But in recent years the government has signaled its intent to open up the sector to private players and last year passed a series of reforms designed to foster innovation and encourage new start ups. Earlier this month Prime Minister Narendra Modi also launched the Indian Space Association, an industry body designed to foster collaboration between public and private players.

One of the companies that has been quick to pounce on these new opportunities is Agnikul, which is being incubated at the Indian Institute of Technology Madras in Chennai. This February, the company successfully test fired its 3D-printed Agnilet rocket engine, just four years after its founding.

While other private space companies like Relativity Space and Rocket Lab also use 3D printing to build their rockets, Agnikul is the first to print an entire rocket engine as a single piece. IEEE Spectrum spoke to co-founder and chief operating officer Moin SPM to find out why the company thinks this gives them an edge in the burgeoning "launch on-demand" market for small satellites. The conversation has been edited for length and clarity.

“We are able to actually create a [rocket] engine from scratch, including the pre-processing, 3D printing, and post-processing, in 72 hours."
—Agnikul COO Moin SPM

IEEE Spectrum: Can you explain what you are building at Agnikul?

Moin SPM, Chief Operating Officer of Agnikul: We are building a launch vehicle that carries a payload capacity of 30 to 300 kilograms, depending on the needs of the customers. We are trying to provide a rapid, on-demand launch service by 3D-printing the entire rocket engine in one shot.

Generally, when you're 3D-printing a rocket engine there are multiple parts that get fused. Or if it is conventionally manufactured many parts are joined through welding or other means. But here the entire rocket engine from the head to the bottom is done in one shot. Normally you have to do a separate qualification process for each individual part, and then another once they have been integrated. Because we print in one piece the qualification time is drastically reduced. So we are able to actually create an engine from scratch, including the pre-processing, 3D printing, and post-processing, in 72 hours.

The engines are the heart of the launch vehicle, and it is around the engine that you build the rest of the vehicle. The other parts will be conventionally manufactured so it is more a case of organizing an inventory supply chain system. But we will be able to assemble and integrate the entire launch vehicle in two weeks. One of the other advantages to what we've done is that the vehicle itself is configurable. We allow our customers to customize the vehicle, depending on the payload. So if I'm carrying only 30 kg, I can fly with seven engines. But if I'm taking 300 kg, I'll be flying with 21.

What did you have to solve to make printing in one piece possible?

First was designing an engine that could be 3D printed. The second thing was the size of the engine. It is not possible to accommodate a normal-sized rocket engine in today's standard printers, [which is] why others are actually fusing multiple components. What we've done is just take the standard 3D printer that is available in the market and designed an engine that can actually fit in it.

“What we want to do is, if you build a satellite, you have an opportunity to launch in two weeks. So this reduces your waiting time, your cost, your other operational costs, your maintenance costs."
—Moin SPM, Agnikul

Has 3D printing constrained the way you designed the rocket?

Standardization is an issue. Each printer has different parameters so the same engine might have certain differences when printed on different ones. But that's why we've actually bought a printer in-house through a deal with [industrial 3D printer supplier] EOS. So now every time the engine comes out of the machine, it is exactly the same as what we have printed before.

What problems does an on-demand launch vehicle solve?

Today, we see a lot of customers waiting for a launch opportunity. One of the primary reasons is that the majority of the launch vehicles carry bigger satellites, so the smaller ones are basically forced to ride share. Second, once there is a ride share the big payload guy would actually infuse a few criteria that have to be met by the smaller players. For example, they might say their satellite has to be radiation protected, which pushes up the cost for a satellite manufacturer.

More importantly, the satellites have to be maintained until the flight. Let's say if you manufactured a satellite in 2021 and you get a launch slot in 2022, for 12 months you have to keep the satellite in a clean room, and you have to maintain the satellite, which is another cost to the company. So what we want to do is, if you build a satellite, you have an opportunity to launch in two weeks. So this reduces your waiting time, your cost, your other operational costs, your maintenance costs.

How is your offering going to be different to the bigger, more established space players like SpaceX?

So there are two segments in the launch industry. You can take an analogy of one being a bus and the other being a cab. The small launch players like us are the cabs, they go from point A to point B on the discretion of the customer. Whereas with the bus, the mission is already planned for the bigger player. The bus goes from one point to another, and all the other players who have joined have to get on at the bus stop.

What stage of testing are you at? Where are you in terms of getting the launch vehicle ready for missions?

We've successfully tested the engines independently and now we are putting them together and trying to do a cluster test. We've got a lot of structural components done, so once the clustering test is finished we'll be integrating the vehicle and I think it should be ready for a test launch next year, maybe around the fourth quarter.

The launches are going to be happening from Sriharikota [an island off India's east coast that hosts the Satish Dhawan Space Centre]. We've entered into an MOU with ISRO to use their facilities to test our systems and subsystems, as well as for the launch.

Firing Agnilet - Repeatability & performance validation test

What kind of customers are you targeting?

We split the market into conventional and unconventional customers. Conventional is earth imaging and communication. But now we are seeing a lot of other industries are trying to use space as a platform. For example, construction companies are trying to use space to monitor how buildings are being constructed. Space tourism is coming up, so are applications for the entertainment industry, the pharmaceutical industry, [and] space data storage.

We are pretty agnostic to the type of player, but we are looking for companies that are trying to do constellations. So before, there used to be only one big communication satellite, now they have turned that into 10 small satellites.

The new satellite manufacturers are also trying to use space to validate the products that they've been developing. This is exactly where the small launch vehicles and on-demand comes in because you shouldn't need to wait for two years, instead your waiting time should be less than two weeks. That's exactly what we're trying to achieve.

The Conversation (0)