NASA's report server is a national treasure, especially the material from the 50s and 60s that he references. Some of the most crisp and succinct technical writing you'll find, and you can infer a lot about how they ran projects. Declassified NRO reports are also very good - you can see the Lockheed Skunk Works principles in action. Example: <a href="https://www.nro.gov/Portals/135/documents/foia/declass/WS117L_Records/984.PDF" rel="nofollow">https://www.nro.gov/Portals/135/documents/foia/declass/WS117...</a>
"At one point, I received a well-deserved earful from our machinist about how tightly spaced the turbine blades were. The program was taking nearly a month to run and required tiny end mills that broke often. We performed a turbine blade count study to see if we could use fewer blades with more space between them. It turned out the performance impact of running fewer blades was minimal, so we cut the number down, allowing our machinist to use larger, less fragile tools. Machine time dropped to less than a day, which was a significant win for turbine cost and machine time. It was also a good lesson in thinking comprehensively about a design’s manufacturability (those passages between the blades looked so big on the computer screen!) in addition to its performance. "<p>Once again people learn the hard way that it's valuable to have tight feedback cycles and embedded knowledge on your team.
Great post on building extremely complex hardware from scratch.<p>At the same time I hate to be that business guy, but both this blog post and the abl site are missing a good answer to my first question: Why? Given that SpaceX exists and is quickly approaching feasibility of Starship on top of Falcon, what is the primary goal of this rocket system? How will it compete? Who will its customers be? Is it getting its metric ton payload to orbit faster/cheaper/easier? Is this "from scratch" engine design superior to existing designs in some way? What is its current ISP? Is Jet-A + LOX a better fuel choice given expected mission parameters?<p>I'd love to see a blog post that tackles these kinds of questions.
Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
<i>> You might call me an unlikely candidate to lead an engine program from scratch, but I was hired by ABL in 2018 to do just that. My background was in commercial aircraft interiors, web development, semiconductor fab fluid components, and SpaceX Falcon 9 hydraulic systems.</i><p>I don't mean this as an insult, but why did they hire you? It's obvious now that you were a great choice, but from your background story I wouldn't have guessed that to be true.
Oh wow, I work for a supplier for ABL and am today in the process of putting some of their stuff into our thermal chamber for cycling. Thats neat.<p>We work for a lot of launcher companies, but ABL is the most interesting for me (even though we do relatively little for them). The containerised approach to the entire system is a really clever adaptation of existing methods to create a rapid launch system.
Awesome story, thanks!<p>It seems the design choices are rather conservative, which is entirely justified by the "from scratch" part for the first engine. I'm sure subsequent designs will be more bold and adventurous.<p>Keep up great work!
The science of pressure chambers have also advanced, we could just pump whatever material, like liquid air into a pressure tank and then load it into the rocket. No mixing or pumping needed just open the valve and let the pressure out and you will have a very cheap and simple rocket.
Since it's 3D printed, I'm guessing from the embedded ports that the nozzle is hollow in parts and Jet A cooled since LOX latent heat of evaporation is orders of magnitude less. Probably one of those ports is for a temperature sensor.
I was wondering what is that space company and what are their edge with spaceX.<p>On the site you can see: launch on demand, simple system that can go anywere, tactical launchs.<p>This is for nukes or similar stuff.