Main Engine Cut Off

The Completely Unsuprising Demise of XS-1

A DARPA launch project, contracted out to Boeing, in the year 2020—I don’t know many people who would have bet on XS-1 panning out. And sure enough, less than three years after the award, Boeing has officially dropped out.

I’m quite happy with how my thoughts on XS-1 have held up, three years later:

With a partially-reusable, flyback, two-stage-to-orbit vehicle operating today, the XS-1 concept is less impressive than it would have been a few years ago. It’ll still be interesting to follow along with, especially as someone who loves launch vehicles, but I can’t help but be a bit disappointed in the decision.

I was hopeful that the XS-1 program would be used as a good opportunity to invest in and develop new capabilities from younger players in the industry. Instead, Boeing is developing a bigger X-37B-like aircraft and putting an SSME on it.

Proactively widening the industry would do more to lower launch costs than working with Boeing on yet another project powered by an SSME-derived engine. “Boeing” and “low-cost launch” have rarely, if ever, been used in the same sentence.