Kerbal Space Program creator looks back on leaving it behind: 'The hardest thing I've had to do in my whole life'

Kerbal Space Program
(Image credit: Private Division)

Kerbal Space Program is now 10 years old, but the kerbals themselves—the little green astronauts who add so much charm to the intimidating space simulator—lived in the mind of creator Felipe Falanghe for a decade before he ever started making his dream game. As teenagers, Falanghe and his brother would turn fireworks into cardboard spaceships, strapping on fins and little bits and bobs to give them texture. "At some point we started strapping little tinfoil men that we would make to the little duct tape cockpits, and we called those guys kerbols," he remembers.

I thought, if I'm lucky I'm going to get maybe six months to work on this... I fully expected that the project was going to be terminated very quickly.

Felipe Falanghe

Falanghe can't remember where the name came from. It just came to them, and over time the pronunciation morphed. Kerbols became kerbals. Eventually he went to college for game design, moved to Mexico, and started working at Squad, a marketing agency that made interactive ad installations that were almost, but not quite, videogames.

Even though he wasn't building rockets anymore, Falanghe held onto the idea of kerbals, thinking that someday, maybe he could make a game about them. 

Kerbal Space Program would eventually succeed beyond his wildest expectations, but that took its toll. After working on it for five years, Falanghe decided he had to quit, letting the game about his childhood toys continue on without him.

"I try to not think about it too much," he says. "But it was the hardest thing I've ever had to do, and seeing it continue to grow without me there is a weird experience. It's like watching your baby get raised by different parents. You can still be proud of the things that it does, but where did it learn to speak like that?"

The unlikely origins of Kerbal Space Program

If you ever thought that it was strange that a marketing company with no videogames under its belt created one of the most important PC games of the decade, well, you're not alone—Falanghe thought it was strange, too, and he was the one who worked there. After taking a job at Squad straight out of college, essentially desperate for whatever he could get, Falanghe quickly found the work depressing. He didn't like advertising, and the nonstop pace of the work was grinding him down. So he walked in one day determined to quit.

"And they said, 'well, don't quit. If you stay with us, we'll let you make your game,' Falanghe remembers. "So that's how it went." He's still baffled by that decision, but assumes that Squad's leaders were also tired of the grueling advertising business and thought it was worth trying something new.

The first pitch for Kerbal Space Program was humble: you'd just build a rocket and see how high it could get before crashing back to the ground, then do it again. "I thought, if I'm lucky I'm going to get maybe six months to work on this [before] they pull the plug and I need to start looking for something else. But I fully expected that the project was going to be terminated very quickly."

He was essentially a solo developer, with one other Squad employee acting as a producer for Kerbal Space Program. Assuming he was working on borrowed time, Falanghe thought it made sense to release Kerbal as quickly as possible, then update it as long as there was interest in the game. This was in 2011, two years before Steam introduced Early Access, but Minecraft had proven it could work.

Because Falanghe didn't expect Kerbal would survive beyond that first six months, he didn't have a long-term design goal in mind for a completed game. "There wasn't so much a design spec as there were ideas for maybe things that I would like to add, if we had the chance." Eventually that meant having to go back to rewrite much of the game's code multiple times to support new features and new versions of Unity, but his focus in the beginning was just getting a game out as quickly as possible. "It was more than just my project at stake. It was my job. I felt that it was do or die for that game to work. That was at least how I felt the first year, year and a half."

Kerbal and Orbiter

Orbiter 2016

(Image credit: Martin Schweiger)

A major source of inspiration for Falanghe was Orbiter, a free, deep space simulation that he had played for years. KSP's physics are simpler by comparison. "It's still is the gold standard of spaceflight simulation out there," he says.

After about seven months of work, the first version of KSP was released on June 24, 2011. It was free, and their projection for a successful first month, solely based on word of mouth, was a humble 900 downloads. They got that within a few days. By mid-July, it passed 50,000.

Interest kept growing and Falanghe kept adding to the game, releasing the first paid version in March 2012. It was a surreal time; because he mostly worked from home, Falanghe didn't have a strong sense of how Kerbal was viewed within Squad—he was more in tune with the game's community. But the paid version was a hit, and Squad started putting more resources behind the game, hiring members of the community to start working on it. That team of inexperienced developers soon went through some intense growing pains.

"We didn't know things like QA and test and deployment pipelines that we would eventually learn later on out of the harshest experiences possible," Falanghe says. "Everything those workflows and methodologies exist to prevent happened to us, and that's how we learned why they're there and useful. I remember the first builds I'd pack manually into a zip file and upload via FTP manually and just hope it was better than the previous one. There wasn't much of a way to keep track of builds or bugs people would report, so I'd just make another version and people would complain to various degrees of volume and I'd try to piece together what was wrong with it… it was a very rough process, in the early days."

Falanghe had once assumed Kerbal Space Program (and his job) were doomed to survive only a few months. Five years later, he would leave Squad because its success made it clear he would have little chance of getting a second game off the ground.

The sweet smell of success

KSP wasn't just my job at that point. It became my identity.

Felipe Falanghe

Expanding the Kerbal team was stressful for Falanghe, who had no experience leading a project. Suddenly there were ideas to compete with his own plans for where Kerbal should go. But that was ultimately a positive—all the community members-turned-developers were as passionate about Kerbal as he was, so even without a rigid design plan, it grew organically. The way people played the game was a constant source of surprise and inspiration, and the community was constantly asking for more realism in the simulation.

"People were actually getting themselves into orbit before they even had information on the interface of the game to know you were in orbit," Falanghe says. "The only way you'd know was that you'd continue going around the planet and not crash. That was really surprising… People were able to pull off things that I thought would be completely impossible, and doing it well before the game had official support for it."

Many of the systems Falanghe designed were about presenting key information to players in ways that wouldn't be too intimidating, like an interface to show you that you were in orbit or when to fire rockets to reach the moon without a daunting wall of numbers. Developing Kerbal's physics system meant spending months with his nose buried in Wikipedia studying physics equations, which he still finds fascinating. Falanghe clearly loves the problem solving of that sort of design and those 'a-ha' breakthrough moments when an idea takes shape. But he experienced fewer of those moments as time went on. His last couple years working on KSP were focused on the career features, adding structure and tutorials to the game that would pull in an audience that had once found Kerbal too intimidating.

Existing players weren't enthusiastic about some of those additions.

"That was a tricky time, because when you announce you've spent the last couple months working on tutorial missions for the community, that doesn't generate a lot of enthusiasm," he says. "All of them already know how to play, so they don't care about tutorials.

"It was quite stressful, but I couldn't imagine myself doing anything else. KSP wasn't just my job at that point. It became my identity. It became something that represented me as a person, which is what made leaving it so difficult, in the end."

Even after five years, developing Kerbal still didn't feel easy. "It was always this grueling, super stressful mindset, do-or-die type thing. Everything was about to explode all the time." After keeping those feelings to himself for so long, Falanghe finally opened up to the rest of the dev team about them, and said they all felt the same. "Once we started comparing experiences it became clear that it wasn't okay to work like this. We shouldn't be working with this level of stress for a game that's doing well and has potentially a nice future ahead of it."

The future of Kerbal was what eventually pushed Falanghe to leave. As far back as 2013, just two years into development, he'd already been coming up with ideas for a follow-up to KSP—a prequel "where you'd invent the history of aviation for Kerbals," he says.

"I found my old sketches dated 2013 where I drew Kerbals trying to pull together a rickety flying machine, and other game ideas I had that I was pitching around that time. Then two years passed and nothing else happened. That's when it started to become really clear [making more games] wasn't the focus. They had us working on features that would get the game ported to other platforms, things like that, and not exploring new ideas. It started to grind everybody down a little bit. Nobody saw a sequel or another game ahead."

Falanghe left Squad in May 2016. Most of the developers he worked with stayed a few months longer, to see through a couple more major updates. In October, eight of them left together. Kerbal Space Program has since continued on with a new team, made up of developers at Squad and modders hired from the community. 

Life after Kerbal 

Falanghe left Squad with no rights to Kerbal Space Program, no ownership over the game based on his childhood rocketry adventures. When he started developing KSP he had signed a contract that guaranteed him a percentage of the profits for five years, which expired shortly after he left. He's grateful for that—back when he started, he thought it would be a win if Kerbal sold enough copies to help him buy a "less rickety" car. In the end he was able to buy an apartment and leave Squad confident in his skills and motivated to create his second game. 

"And then I got out into the real world where game development happens, and that was a pretty, I guess you could say confidence-reducing experience," he says.

KSP grew so much beyond being my own little game idea that it's an institution now, it's become its own thing. It's not just my thing.

Felipe Falanghe

Falanghe spent all of 2017 pitching investors on a "large game project," but he got nowhere. "It's not like in Shark Tank where they'll say I pass, and that's it. I guess because none of them want to be the guy who turned down The Beatles, in case they said no to something and it turned out to be good. They never actually tell you no, they just string you along. You never get an end to the conversation."

Frustrated after wasting an entire year, Falanghe decided to start small again and began making a game based on another childhood activity with his brother: making model airplanes. Balsa Model Flight Simulator was originally conceived as a VR game, but after releasing an early version on the Oculus store in 2018, he realized that an RC flight sim for VR was not exactly reaching for a large audience. Balsa sold poorly, but it still attracted the attention of indie publisher Irregular Corporation

"There have been, I'd say, 2-3 things I'd call minor miracles in my career," Falanghe says. "One of them was the opportunity to make KSP in the first place. The second one was signing with the Irregular Corporation when I did, because I was weeks away from pulling the plug and going to look for a job. In the nick of time is an understatement."

By then development must have already started on Kerbal Space Program 2, which was announced at Gamescom in August 2019. Falanghe was completely surprised by the announcement—no one ever reached out about it. If he'd been offered a job in 2018, he said he would've leapt at the chance. "I was still in the wake of the terrible period of not making much progress with the ideas I had in mind when I left KSP," he says. "If they said 'oh there's this other team now working on the sequel to KSP itself,' I would've gone immediately."

KSP2 publishers Private Division did eventually get in touch with Falanghe, just within the last few months. But since signing with The Irregular Corporation, for the first time in his development career, everything was just… easy.

Falanghe has worked on Balsa for the last two years with one other developer, building out the game and converting it from VR to flat screens. He plans to release it on Steam Early Access in the near future.

In another twist, it's no longer being published by Irregular Corporation—after the parent company was bought out, Irregular dropped some projects, including Balsa—so Falanghe is indie once again. After a blissful couple of years he's back to feeling some pressure, but he's excited to release it. He calls Balsa a "new first step" in his career rather than the second step that his abandoned 2017 plans would've represented. He tries not to think too much about working in the shadow of his first game. "I've no idea how it's going to be compared to KSP. It's entirely a new experience for me, and hopefully for players too," he says.

"I think that KSP grew so much beyond being my own little game idea that it's an institution now, it's become its own thing," Falanghe says. "It's not just my thing. It hasn't been, for a really long time. It's its own thing and there's a lot of really passionate people now working on it. It's kind of like having a child. It eventually becomes its own person. ... To me it feels very much like that kind of thing, seeing your child grow up and leave the house. Now it's living with somebody else you don't really know, and it's weird. But at the same time it makes you feel proud."

Wes Fenlon
Senior Editor

Wes has been covering games and hardware for more than 10 years, first at tech sites like The Wirecutter and Tested before joining the PC Gamer team in 2014. Wes plays a little bit of everything, but he'll always jump at the chance to cover emulation and Japanese games.


When he's not obsessively optimizing and re-optimizing a tangle of conveyor belts in Satisfactory (it's really becoming a problem), he's probably playing a 20-year-old Final Fantasy or some opaque ASCII roguelike. With a focus on writing and editing features, he seeks out personal stories and in-depth histories from the corners of PC gaming and its niche communities. 50% pizza by volume (deep dish, to be specific).