How a SpaceX engineer ended up working on a spiritual successor to Kerbal Space Program

Late last year, RocketWerkz shared the first details of Kitten Space Agency – a spaceship engineering management game from a team including the original developer of Kerbal Space Program, which aims to fill the sparking void left by the downfall (or is it?) of Kerbal Space Program 2. Aside from introducing feline astronauts, the game runs on a new engine that can support a fancier and more consistent physics simulation.

It looks like catnip for Kerbollards (TM), though I have some broad reservations about the project’s use of new community-funding platform Ahwoo. Among those working on Kitten Space Agency is Stefan Moluf, an actual real-life former spaceship flight software engineer, who wrote code for SpaceX launch vehicles and rockets back in the 2010s. In addition to discussing the game, which you can read about in depth here, we talked a little last year about how Moluf jumped between industries, and how programming rockets compares to programming rocket games. Fear not, the following chinwag makes no mention of Elon.

RPS: How did you get into the space industry, and what did you do while you were there?

Stefan Moluf (SM): I joined SpaceX right out of college as an intern and worked there, ultimately, for 12 years, during the period about 2009 to just after 2020. So for a lot of the early expansion and development, I was there. It was real small. There were just 12 separate engineers, when I first joined.

So I did that for a long time, really enjoyed it, and eventually I left to go do some other startup work. Basically, I just wanted to work for a small company, and that was the thing that SpaceX couldn’t be again. So I did various things there, and then I always had in the back of my mind that I wanted to work in games, just because it was one of the few areas of software I hadn’t really done before. And definitely with my spaceflight background, I kind of wanted to work on a spaceflight thing.

I was thinking of just doing something on my own, and when [RocketWerkz founder Dean Hall] sent out his announcement that Kitten Space Agency was under development. I basically just emailed him and said, hey maybe I could help out, and that’s how I got to do what I’m doing now.

RPS: Can you tell me a bit more about the projects you worked on at SpaceX? Is there anything anything that I’d recognise?

SM: Basically, if you’ve seen a SpaceX headline, I’ve probably worked on most of it, and certainly, stuff that I’ve worked on is still running on all of it. So I worked on initially a lot of the communication systems for the Falcon 9, the very first version which is sort of SpaceX’s workhorse rocket these days.

I started in communications and then just worked on pretty much everything – the low level infrastructure, guidance code, a bunch of other different things for our Dragon spacecraft, both the version that carried cargo to the space station, and then to a lesser degree, the one that carried people to the space station.

I did a little bit of work on Starship, before it really got going – the big rocket that’s getting caught by towers and making headlines. I did some early work on that program. So kind of a bit of everything.

RPS: I’ve heard that space companies are interested in hiring game developers because there’s an overlap in terms of the skillset – the tasks you have to solve in games are complex and a good foundation for thinking about outer space technologies. Is that fair?

SM: Yeah, that’s 100% true. A lot of really great people that we hired at SpaceX came from games. There wasn’t a majority, but there was definitely a strong hiring pipeline from the games industry.

And it’s probably not obvious, if you’re not a programmer, why that is, but the things you have to do when you’re controlling hardware for a rocket are very different from what you’re doing if you’re writing a program for a website. The website is all this stuff loaded in the server somewhere. It gets downloaded to your browser and then launched. It’s all these text files and all this different stuff that’s built up over a long time through the web.

For a rocket, you generally have one computer or a couple of computers networked together, with a little private network that only you can see. You’re writing code that has to run on time – you have to deliver, you know, updates to the hardware, control the hardware, [exactly on time] or things fall apart.

Games are a little bit more like that. You generally have one computer that you’re on. You’re running software that has to display a new frame to the player, every 30 hertz or 60 hertz, or whatever it’s going to be. There’s a lot of similarities in the environment and the requirements.

In a lot of ways, games are actually more complicated – there are more considerations there. The other side of that is the rocket work is a lot more rigorous. The consequences of failure are a lot higher! So there’s definitely differences. But they are actually quite akin to each other in a lot of ways.

RPS: Thank you, I hadn’t thought about framerate in this context – that’s really interesting. To go back to your personal journey, when you were thinking about moving into games before you started to work on KSA, did you have any particular projects or ideas you made a start on?

SM: Because obviously, my professional experience was in space flight, I was interested in that. I actually originally thought about applying to work on Kerbal Space Program 2, but they were all up in Seattle, and I wasn’t prepared to move out to Seattle. So I never actually did that. And then ultimately, unfortunately, that project didn’t turn out so well, so I’m glad I didn’t.

But I thought you know, if that game is is dead, the one I wasn’t going to work on anyway because I wasn’t going to move, maybe I’ll just make my own, maybe I would even start my own company, if that’s what it came down to. And it was right at the time when I was thinking about doing that, that Dean said, hey, we’re making this game, and if you want to come work on it, let me know.

So I said yeah, that’s basically exactly what I intended to do, it’s just someone’s already doing it, so I’ll gave it a shot. But yeah, I was gonna work on a spaceflight thing. I think like anyone who has thought a little bit about games they’ve played, I definitely had other ideas, but this was the obvious most promising one because it was the thing that I knew the best.