How Did SpaceX Go to Mars... The Answer Lies in This Photo [Tech Talk]

SpaceX's Raptor Engine
Simplified Over 3 Generations
Cost Reduction at the Core of Innovation

On the 4th of last month (local time), the American private space launch vehicle developer 'SpaceX' released a photo. The photo shows rocket engines mounted on SpaceX's main launch vehicles, Vulcan and Starship.

From the left, 1st generation Raptor engine, 2nd generation Raptor engine, and the latest 3rd generation Raptor engine
[Image source=Ex(X)]

SpaceX uses only rocket engines that it designs and manufactures itself. In the past, it used Merlin engines, but currently, it employs a new concept engine called the Raptor engine. This photo is particularly important because it shows how the Raptor engine has evolved through three generations. Above all, this engine embodies the 'technology philosophy' of SpaceX and, more broadly, CEO Elon Musk.

"The best part is no part"

Looking at the photo, you can immediately grasp the direction in which the latest Raptor engine has evolved. The 1st generation Raptor engine has pipes, valves, and mechanical devices cluttered around the engine exterior. It is not much different from other rocket engines. However, in the 2nd generation, many of these parts disappeared, and by the 3rd generation, it looks as if it was molded all at once, presenting a clean appearance.

'Reducing parts' is the area SpaceX focuses on more than any other technological research. This is also the most important mission CEO Musk has assigned to the company. It is the so-called 'The Best part is No part' strategy. Musk emphasizes this phrase every time he explains SpaceX's competitiveness.

The fundamental technology of rocket engines was almost completed in the 1960s. In other words, the core of engineering was already proven long ago. The difficulty of rocket science lies not in advanced technology but in the complexity of the engine itself.

Countless pipes, valves, and seals carrying explosive fuel are integrated inside and outside the engine, and these parts must operate precisely without the slightest error during the long ignition period as the rocket escapes Earth's atmosphere. During this process, they must also withstand extreme heat and friction. No matter how meticulously parts are made, the risk of engine explosion cannot be completely eliminated. Ultimately, the best way to improve engine durability is to eliminate parts altogether.

Up to now, SpaceX has developed three generations of Raptor engines, researching designs that integrate multiple parts into one and incorporate parts previously exposed on the exterior into the interior. They have also aggressively adopted 3D printing to standardize the quality of all parts.

Thanks to this, the weight was reduced from 2 tons (Raptor 1) to 1.5 tons (Raptor 3), and manufacturing costs were cut by about half. The improved weight-to-thrust ratio is an additional advantage proportional to the reduced weight.

The Starship rocket igniting 33 engines simultaneously. Rocket engines are complex machines controlled mechanically, making this nearly impossible with conventional engines.
[Image source=SpaceX]

The simplicity of Raptor 3 enhances vehicle stability and enables feats no other rocket could perform. Musk's greatest aspiration, the largest and most powerful rocket Starship, must control 39 engines at once (6 on the first stage + 33 on the second stage). Without pursuing extreme simplification, the development difficulty would have been much higher than it is now.

The core of Musk's innovation is 'simplification'... but it can be a double-edged sword

'Simplification' is the single technological philosophy that runs through all the companies Musk has established. Whether it is SpaceX, the internet satellite Starlink, Tesla, or even the social networking service X (formerly Twitter), Musk pushes for simplicity.

For example, Starlink satellites become smaller and simpler with each generation. This is because the lower the manufacturing cost, the more advantageous it is to periodically scatter tens of thousands of internet satellites into Earth's orbit.

Tesla's world-first application of the 'Gigapress' also stems from a commitment to simplifying manufacturing processes. It is a method of casting an entire car chassis at once using a single massive casting machine.

After acquiring X, formerly Twitter, Musk's first action was mass layoffs. The strategy was to remove all but essential personnel needed for SNS operation and management, then gradually expand focusing on service optimization and research and development (R&D) critical for future competitiveness.

6000-ton-class Idra Giga Press that stamps the vehicle body in one go.
[Image source=Idra official website]

However, the business strategy represented by simplification and cost reduction is not always effective. In emerging technology fields like reusable rockets and electric vehicles (EVs), when the market is just opening, factory production capacity and supply chain capabilities are insufficient, causing costs to soar. Companies that produce as many units as possible at the lowest cost have an advantage in gaining market share.

But as the market becomes saturated and competitors emerge, the effectiveness of the simplification strategy rapidly declines. Consumers begin to demand high-quality products beyond just price competitiveness.

Moreover, if implementing simplification requires introducing new equipment or technologies never seen before, initial investment costs will sharply increase. Tesla, the pioneer of Gigapress, announced in May that it would abandon full implementation of Gigapress. The investment cost of the bespoke, extremely expensive large press machine became a stumbling block.