Several weeks ago, Astropreneurs had the distinct pleasure of speaking with Andy Kieatiwong, CEO of Additive Rocket Corporation (ARC), a San Diego company on the cutting edge of 3D printed rocket engines. ARC is on a mission to democratize space by providing reliable and affordable propulsion systems for small rockets and spacecraft.
Astropreneurs: Hi Andy, how and when did you lay the foundation for your company, ARC?
Andy Kieatiwong: I actually started ARC with several friends while studying aeronautical and astronautical engineering at the University of California, San Diego. After working together in student clubs and interning at aerospace companies, we were inspired to start our company with a unique mission and method in mind.
Astropreneurs: What aerospace company did you work at before starting ARC?
Andy Kieatiwong: I worked as a manufacturing engineer for SpaceX’s Dragon fluid systems group. We helped build and test the fluid systems for both the Draco and Super Draco engines used on the crewed Dragon capsules.
Astropreneurs: How did working for SpaceX affect your vision when creating ARC?
Andy Kieatiwong: Working at SpaceX was an amazing data point for both myself and my team here at ARC. It taught us how other space companies are using additive metal manufacturing to create their hardware components, and also helped validate my vision for ARC.
Astropreneurs: Tell me about your vision.
Andy Kieatiwong: My vision for ARC is to optimize contemporary propulsion designs in order to decrease cost point, weight, manufacturing time, and the number of parts required for a system. Traditional engineering/manufacturing methods are antiquated. For decades, engineers have designed systems in order to adhere to traditional manufacturing methods, often at the cost of optimization and efficiency.
Here at ARC, we design systems for maximum optimization and efficiency, then use additive manufacturing to build our designs. This methodology was practically impossible before metal 3D printing.
Astropreneurs: Could you describe for our readers how ARC engines distribute fluids and heat better than traditional rocket engines?
Andy Kieatiwong: With additive manufacturing, we make available the unique advantages in design that additive manufacturing allows. Previously, engines have been designed for manufacturing optimization rather than design optimization. However, with additive manufacturing, one can design propulsion components without limits. We create designs that mimic the fluid transfer systems of blood vessels and tree roots: we call it nature-driven geometry. Mother nature has already optimized fluid transfer system—they are all around us. As it turns out, the computer algorithms we use to optimize designs end up being biomimetic and allow for increased engine performance.
Traditional engineering welds fuel lines around the injection chamber. We simply print channels inside the wall of the motor. 3D printed fluid lines have better heat diffusion characteristics than traditional methods. We currently print using single material designs, and by using the inherent properties of the nickel-chromium based super alloy, Inconel, we are able to efficiently transfer heat from the rocket motor walls into the fluids running throughout the interior of the motor. We do this by decreasing the inner wall thickness of the motor so as to have better heat conduction from the inner wall to the cooling fluid. Because we are printing with a single material, there is far less risk of cracking and misalignment due to heating/expansion.
Astropreneurs: How will nature-driven geometry change propulsion going into the future?
Andy Kieatiwong: We see this as the next step in the evolution of hardware. Using 3D printing, we can use the optimal shape for any system. We are seeing a lot of interest in this process across the space industry and beyond. The long-term vision for ARC is to see our biomimetic technology improve hardware systems and allow for breakthroughs in every industry.
Astropreneurs: Are ARC engines really just one single piece? Because that’s pretty incredible.
Andy Kieatiwong: Well, a standard propulsion system is made up of many parts, such as tanks, tubes, etc. Depending on its thrust range, a traditional engine’s injector plate, cooling system, combustion system, and exhaust nozzle could range from 5 to 500 pieces. With additive manufacturing, we can build root-like channels through an engine’s injector plate to run fuel instead of using additional pieces. So, after the turbo pump and valves, we place a final, one-piece motor system into the rocket. This drastically reduces the system’s weight. Not to mention, with fewer bolts, breaks, and nuts, there are fewer failure points. Our goal for the near future is to move beyond the rocket motor and also optimize the turbo pump and valves.
Astropreneurs: You’ve successfully printed and tested a 3D printed rocket engine: do you have any plans to 3D print full rockets?
Andy Kieatiwong: Printing an entire rocket is not what we have envisioned for our company. This approach is more in alignment with companies like Relativity Space. For us, we’re looking to enhance the performance of specific mission critical components like motors, turbo pumps, and valves. By optimizing the components that see the most heat flux, corrosion, and stress during operation, we hope to provide the greatest possible benefit in cost reduction and overall performance. Basically, we want to apply our technology where it matters the most.
Astropreneurs: So, besides ARC’s potential for generating monetary gain, what drives you to wake up each morning and design, print, and test rocket engines? What is the best reason to help people get to space?
Andy Kieatiwong: For me, the value of space becoming more open is that even small agencies, organized hobbyists, and university programs can send projects into space. This allows new ideas—and potentially better ideas—unprecedented access to the incredible testing platform of outer space. My hope is that this increased access will galvanize more and more students entering college to see space as a tangible reality. This would be an amazing culture shift, especially considering that access to space felt like an impossible dream for my generation, reserved only for astronauts and giant governments/corporations. It’s time that we even the playing field.
Astropreneurs: In a recent interview, you stated that ARC was shifting its focus from large rocket engines to small satellite propulsion: why the shift, and will ARC continue developing larger rocket engines?
Andy Kieatiwong: First of all, we are not really shifting our focus, but concurrently creating designs and components for both satellites and rockets. Our satellite propulsion designs use cold gas/mono propellant thrusters and will allow for better attitude control and easier orbital adjustments. Frankly, there are more satellites than rockets in the space industry, and we are approaching this larger market by offering reliable and affordable in-space propulsion. Small satellites don’t typically use chemical or cold gas propellants because those systems are quite heavy. But thanks to 3D printing, we are able to decrease the number of parts (and therefore, the weight) of these systems, allowing for the manufacture of smaller motors with the same Delta V as a much larger/heavier system. We want to enable satellite builders the option to not give up Delta V by settling for electric or ion propulsion systems when we could provide lower cost cold gas or chemical propulsion that provides greater delta V per kg of the system. Basically, we want to provide more options for satellite manufacturers. However, this doesn’t take away from our development of bi-propellant motors for launch vehicle development.
Astropreneurs: What was your biggest inspiration to enter the propulsion/space industry? Why rocket engines?
Andy Kieatiwong: My interest in space was awakened when I was four years old, watching Star Wars: A New Hope on VHS. I decided I wanted to build space ships when I grew up. Either that, or dig up dinosaur bones… I ended up taking the space route.
Astropreneurs: In your opinion, what would be the coolest possible thing to 3D print?
Andy Kieatiwong: We often go on for hours about this at the office. I think you would get different answers from everyone on my team; however, my wildest dream would be to print exact replicas of different Star Wars ships. If I could print a Millennium Falcon out of metal, I would live in it.
Astropreneurs: Okay Andy, here’s my final question: you’re stranded on a tiny island in the Pacific for six years with nothing but a solar powered record player. After a few weeks, a giant cargo jet explodes over your island, dropping millions of vinyl records into the sea. You can only swim out to save one record: which record do you rescue for your 6-year stay on the island?
Andy Kieatiwong: I would choose the Golden record on Voyager – It goes back to the spirituality of it. When they made the record, it was designed to capture life on Earth as we know it: whale songs, bird songs, greetings in multiple languages, science, and photographs. I think it’s a good metaphor for being on an island where you may think that you’re alone. I think having that record would be a humbling experience, simply knowing that there are other lives out there in the vastness of the universe. I think it would remind me to make the most of what I have on the island. When I first heard about the golden record, it represented for me humanity’s hope of sharing our experiences with other people. Even if no one out there ever finds it, we gave it an honest try. Besides, voyager is set to approach another star system in 40,000 years… so borrowing the record for six years shouldn’t be too much to ask.
Posted by Marshall McKellar