[bumby]

Thanks for clarifying.

That’s interesting because I would assume a reused structure (rather then reused design) would be at greater risk for failure. More fatigue cycles etc.

I believe in the case of govt payloads they are self insured to around 80% or so but that’s obviously a different case. I also wonder if that affects the business plan for how to decide which payloads go on which rocket

[nickik]

Well, when you get in a plane, would you rather it be the first or the 100s?

There is basically a curve from where its more risk in the early launches and then gets better, as it nears end of live, risk goes up again.

[bumby]

Depends on what you mean.

I’d like to be at or near the first flight of a new plane using a time-tested design.

Failure rates (more specifically hazard rates) in most components tend to increase with time (I.e., follow a time-dependent failure model like a Weibull distribution and not a constant rate model). The “bathtub” curve is usually more associated with components with a constant failure rate (where the ideal place is after infant mortality but before wear out).

There are two types of uncertainties here and I think we’re talking about different ones. One is a design uncertainty that can be mitigated using a well-used and understood design. The other is a component failure uncertainty which increases as service life increases. So the ideal place to be is in a well-vetted design with new-ish components.

[nickik]

I not arguing about design uncertainty, rather production uncertainty. A failure in the production is more likely to fail on the first flight then the 3rd.