Optimistic Tech Newsletter: Stoke Space
Scaling a vibrant space economy
I will admit to you, dear reader, that for the longest time, I could not conceive of the need for space travel in the 21st century. Rockets are amazing, I know, but we’d been to the moon, we had innumerable satellites and the ISS. What else did we need with space?
But then I did some reading, not physics textbooks but fantastic novels like Seveneves, The 3 Body Problem Trilogy (please read the books, do not watch the abomination on Netflix), Delta-V, The Salvation Series, Rendezvous with Rama etc etc and quite frankly I realised that it is inconceivable that humanity should not expand into space.
Much like exploration in the middle ages, not everybody needs to jump on a boat and sail. But some people have that insatiable desire to explore, to be the first, to go further. And the rest of us get to reap the benefits. I am, for a lack of a better term, space-pilled. Which brings me on to Stoke Space.
I too am space-pilled now. Tell me about Stoke
The thing about space is that it’s expensive. It’s expensive to get there, it’s expensive to stay there, it might actually just be expensive to think about. Imagine if every time you wanted to drive somewhere, by the time you arrived back on your driveway, your car was now unusable. And to go on your next journey, you needed to buy a new car.
A) The cost would rack up pretty quickly and B) You’d take faaaaar fewer journeys. So one of the ways to make space more accessible is to make the rockets reusable. And also to make those rockets more efficient and cost-effective. Which is exactly what Stoke has done.
Their reusable Nova rocket offers a 20x reduction in getting to orbit. Not only that but by using a different fuel combo than other rockets which use kerosene, Stoke rockets create much fewer harmful emissions as they launch compared to other rocket companies.
OK I’m ready to go to space, tell me what else is special about Stoke
How about the fact that they’re so good at in-house manufacturing (yes, Stoke is vertically integrated and manufactured in-house) that they have actually built a separate product to help other hardware startups manage design, parts and people. If you’re considering building a hardware company, check out Stoke Fusion.
It turns out that one of the trickiest aspects of building a reusable rocket is the heat shield. Personally I’d just use Vibranium but maybe these guys don’t have the contacts in Wakanda that I have. Anyway, Stoke have come up with a unique solution in building a heat shield that is literally bullet-proof and cooled by liquid hydrogen fed through the metal.
Let’s talk Milestones
Yes, lets. So while B2B SaaS companies and AI companies can post hockey-stick graphs of revenue, building a rocket company is a significantly slower burn (muahahaha see what I did there. I’m so funny). Because you actually have to build a FUCKING rocket before you make any money. So rather than cold, hard cash, let’s look at some technical milestones:
Last year Stoke successfully tested their custom designed first-stage engine. I mean look how fucking hard this pic goes:
Stoke recently announced their Andromeda engine which will be their upper-stage engine. Not to shower this post in video’s but check it out:
Stoke was selected by the United States Spaceforce to take part in their $5.6bn National Security Space Launch Programme.
First launch of Nova is expected at the end of 2025
Who is building this space behemoth?
Andy Lapsa’s the name, sending rockets to space is the game. Andy has been building rockets since he was a kid and followed his dreams and joined Blue Origin right out of university. He was there for 10 and a half years before starting Stoke in 2019. Lapsa has said of Stoke “Part of the big thesis of the company is, how do you build a fully, rapidly reusable space vehicle that goes to space, performs a function, comes back and turns around and flies again.”
Now obviously one doesn’t build a rocket company alone. There’s a team of around 250 people and Stoke have raised nearly $500m from incredible investors like YCombinator, 776, Breakthrough Energy and Spark Capital.
Why is this Optimistic?
Like I said at the beginning, I’m space-pilled. I believe in exploration, I believe that those crazy people who sought out new lands and in the future will seek out new worlds will bring incredible benefits to the rest of humanity. We need those explorers to thrive as a species.
And those crazy people need to be able to get themselves and other stuff into space in a reliable, efficient and economical manner. I believe Stoke is on the cutting edge of that and that’s why I love them.
First stage rocket reuse was solved by SpaceX: Simply keep extra fuel in reserve, fall to the ground, and use your existing engines to land.
Second stage reuse is a much bigger challenge because the energies involved are far too high to do the same. There are three main approaches to this problem:
1) Space Shuttle type winged landing
2) SpaceX's belly flop
3) Stokes dual use aerospike engine.
The problem with winged landings is that wings add a lot of weight and are useless outside the atmosphere. It also requires tens of thousands of protective tiles.
SpaceX's Starship gets around this by using movable fins to control the initial reentry, then using its engines to flip it upright for landing. Though it still needs protective tiles.
Stoke's approach is my favorite. Instead of fins, wings, and tiles, Stoke uses a hydrogen-fueled, quasi aerospike, expander cycle engine the second stage for ascent.
Then, on decent, they reenter with that 'aerospike' windward and run the expander cycle with the engine nozzles closed. Using the rockets own fuel to cool it down.
This makes brilliant use of the hardware and saves mass. The engines, already capable of withstanding extreme heat on ascent, are also used for decent. No separate hardware required:
https://www.lianeon.org/p/the-race-for-the-holy-grail-of-rocketry