Rapid Rocket Reusability with Stoke Space CEO Andy Lapsa

In this hour and a half interview, Stoke Space founder and CEO Andy Lapsa describes the company’s approach to building a 100% reusable two stage launcher whose design some observers have called “weird”. They use liquid hydrogen as fuel instead of the safe bet of kerosene or trendy liquid methane, have 30 fixed small thrust chambers around the outside of their second stage which provide thrust vector control by differential throttling rather than gimballing, actively cool the non-ablative heat shield with hydrogen during re-entry, bring the payload fairing back along with the upper stage, and use stainless steel for primary structure instead of lighter aluminium or carbon composites.

The goal is quick turn-around 100% reusability with airline-type operations (gas it up and go, as opposed to lengthy inspection and refurbishment between flights). Lapsa explains the engineering rationale for each of the design choices and how they are intended to fit together into a medium sized launcher that will be economically competitive with SpaceX’s Starship.

If the interviewer said “gotcha” one more time, I might have been tempted to drown myself in the toilet bowl.


The capital productivity is really high for the Superheavy booster but not so high for the Starship – due to the rate at which each can be put to use for the next payload. I wonder how this affects the economics of Stoke Space?

This isn’t the same as capacity utilization rate since one can be at full capacity utilization but I’m not sure what to call it. It seems this affects any two-stage system – and is even worse for a single stage to orbit system since it has no booster to fast-cycle.