Spacex’s New Strategy: Build Rockets, Then Blow Them Up
Spacex tries a risky new strategy for spacecraft development
|Feb 23, 2020|
Elon Musk is known for breaking the mould with virtually everything that he touches. He has consistently demonstrated a knack for thinking about products and services in terms of their “first principles.” Viewing through the lens of first principles, he is able to find new ways of approaching problems that have led to breakthroughs in technology. But in some of his latest statements, however, Elon displayed a level of ambition that must make even himself nervous.
While many people are aware that SpaceX is building the SN 1 Starship prototype in Boca Chica Texas, what is less known is that SpaceX intends to build these prototypes quickly, cheaply, and quite literally by the dozen. By cheap, for as little as $5 Million apiece and by fast, cranking out a brand new spacecraft at a rate of two per week. For some perspective, at that rate, Starship spacecraft will resemble an ensemble of small skyscrapers while they are parked here on Earth. While those targets seem impossible (I personally doubt that they will ever be built that fast or cheap) statements such as these illustrate Elon’s development approach from here going forward.
In some regards, the idea of building two Starship spacecraft every week feels counter-intuitive. The Starship rocket is intended to be the first fully and rapidly reusable rocket. If new upper stages are being cranked out at >100 per year, and these stages can be flown somewhere between 10 and 100 times each, how could there possibly be enough payload demand to justify building that many? In theory, if the Starship rocket succeeds in lowering the cost of spaceflight, it should lift the demand for people and payload going into space. But just 100 Starships, each carrying at a minimum of ten tons of payload and flying at least ten times each, would loft an incredible 100,000 tones into orbit. I suspect that there will not be demand for that sheer launch mass for a very very long time.
A later tweet from Elon, however, clarified some of his thinking and why so many Starships would be necessary. He noted that the reason that Spacex was keen on building so many Starships was an effort to advance spaceflight technology much quicker than had been done in the past. In typical Muskian fashion, he presented his thought in a simple formula:
Technological Progress = Iterations x Progress Between Iterations
The switch to stainless steel is what makes this all possible. Stainless steel is vastly cheaper than carbon fibre and much quicker to build with. The approach that Spacex is taking is to build prototypes cheaply and quickly, with each prototype featuring small improvements in the design and manufacturing process.
This is not unlike the Falcon 9, which was able to gradually demonstrate rocket landing technology and reuse, and which famously boasted that no two rockets were alike. Each launch tested a minor improvement in design. But, as Elon noted, the difference between each Falcon 9 iteration was very small because the Falcon 9 was launching satellites for paying customers…customers who would not have wanted their valuable payloads risked for the sake of SpaceX's technological progress. In other words, Falcon 9’s development was risk-averse.
Stainless steel allows for cheaper construction and faster iteration of the Starship launch vehicle. Additionally, as Starship is not carrying customers payloads, the progress between iterations can be larger. The result will be, however, a lot of failures. Instead of carefully modelling and testing each component to perfection before testing, components will be designed and built “good enough” to such an extent that they can be quickly tested. The testing will reveal design or manufacturing flaws, which in the rocket industry are usually illustrated in explosions.
In other words, be prepared for explosions….a lot of them. But don’t worry, it’s progress.