Writing · July 2026

The missing fitness function

Late-career notes on leaving NASA — what I’d taken for the summit of human spaceflight — and the question it couldn’t ask.


When I got my aerospace degree, NASA was mecca — the place anyone serious about human spaceflight was supposed to want to end up. Or at least it was what I thought mecca looked like. I got there, in my early twenties, and then I left — and the reason I left is most of what this is about.

I was doing structural and mechanical analysis on the Space Shuttle — the work that decides whether a piece of flight hardware is allowed to fly. Eventually I held signature authority for stress analysis, which means that on some pieces the last thing standing between an engineer’s drawing and metal going to orbit was my name, saying the numbers held. There is not much in engineering that concentrates the mind like that.

And I left it. Not because the work wasn’t good — it was the best work I have ever done — but because I came to see that what I’d taken for the summit had something missing from it.

NASA runs on a ruthless fitness function. Does it fly. Does it hold. Does it dock. The physics doesn’t care what you hoped for, and a wrong answer isn’t an embarrassment, it’s a consequence, so you learn very quickly to want the analysis to argue back. That part shaped me permanently, and I wouldn’t trade it.

But there is a question that world is mostly blind to, and it took me a few years inside to see the shape of it. Nothing there was priced. A brilliant analysis and a wasteful one looked identical from where I sat; the elegant solution and the one that cost three times as much for no good reason both got the same signature, because the thing being optimized was correctness, not worth. There was no market pressure, no profit and loss, no economic selection telling you whether what you were doing was worth what it cost. You could be genuinely excellent and never once have to answer that question.

I don’t say that as a complaint. Some work should be insulated from the economic fitness function — you do not want the person signing off on a pressure vessel running a cost-benefit analysis on the safety margin. But I started to want to understand the other fitness function, the one that governs nearly everything outside the fence. Technical work asks a simple, brutal question: does it work? Economic work asks a different one that is just as brutal once you take it seriously: is it worth it? I had spent eight years getting fluent in the first and had no real feel for the second.

So I started an MBA while I was still there. Not, at first, to leave — I told myself it was to round out the picture, and I don’t think I fully believed that even then. What I actually wanted was to be bilingual: to be able to hear “no” from the market the way I had learned to hear it from the math.

Leaving was awkward, the way these things are. I left mid-degree for a finance seat, mostly to prove to myself that the new language was real and not just something I could talk about. Then came years of consulting, which for an engineer is largely the job of translating. You sit between people who speak in tolerances and failure modes and people who speak in margins and timelines, and for a while you are fluent in both languages and fully trusted by neither.

The work took me on a strange tour of things that either work or hurt someone: aircraft carriers, commercial jets, pacemakers, cars. They run on the same unforgiving physics NASA does — a wing holds or it doesn’t, a pacemaker keeps a heart going or it doesn’t — but I was there for the other side of the ledger: the manufacturing strategy, the program economics, the cost of a decision made years before anyone flew or drove or woke up with a heartbeat they didn’t have to think about. It was the honest-feedback lesson NASA had taught me, stretched across a dozen industries — except this time the economic fitness function was in the room too.

That went on longer than I’d like to admit.

Somewhere in there I ran my own business, and that is where the two functions stopped being a translation problem and became the same problem. When it’s your company, you execute and you sell in the same afternoon, to the same people, with your name on both. There is no department to hand the economics to and no engineer to hand the build to. If the work is good and nobody will pay for it, you starve; if people will pay for it and it doesn’t work, you starve a little later. Nothing has taught me the lesson faster.

That is when the two stopped fighting each other — not because I had reconciled them, but because owning both at once leaves no room to pretend they’re separate.

Cloud architecture isn’t where the two questions finally reconcile — I used to tell it that way, and it’s too tidy. It’s just how far I’ve gotten under all of them at once. The professional world doesn’t hand you two clean fitness functions to reconcile; it applies a whole messy set — technical, economic, organizational, political, the plain accident of timing — and a career is mostly how far you get while all of them are grading you.

What I like about the work is that two of those functions are unignorable in the same afternoon. You can build the technically immaculate system that no one can afford to run, and you have failed — on the axis engineers are trained not to see. Or you can build the cheap thing that falls over under real load, and you have failed on the axis the business was trained not to see. It isn’t a resolution of the two questions. It’s just a vantage point high enough to see both of them coming.

That is also why this site is a strange little collection — a spacecraft simulator, a tool for pricing cloud designs, a pool calculator, a driver’s app. They look unrelated. To me they are the same instinct: a suspicion of any answer that has only been checked against one fitness function. The pool either stays clear or turns green. The rendezvous either docks or it doesn’t. The design is either worth it or it isn’t. I like the problems where you can’t argue with the result, and I have spent a career trying to stand in the one place where two different kinds of “no” can both reach me.

The private itch that pushed me out turned out, I think, to be the larger story of the field I left. For a generation, human spaceflight was held back less by physics than by that same missing fitness function — a program optimized for correctness and prestige and, rightly, for safety, but almost never for cost, and so it ossified. That is finally changing. Commercial spaceflight is, more than anything, the application of economic pressure to something that never really had it — and you can watch the pace of the whole enterprise change the moment that pressure arrives. The thing I went looking for in an MBA is now remaking the field I trained in.

I’m writing this near the end of my working life, which is the point where you stop measuring a career by what’s ahead of it and start trying to see the shape of what’s behind. This is the shape I’ve found.

I still think leaving was the right call. Not because the second fitness function matters more than the first — it doesn’t — but because I wanted to be able to hear both. That turns out to be most of the skill.