Boom Supersonic: From Cardboard Mockup to Legalized Flight

In 1969, humanity achieved remarkable feats, landing on the moon and flying the Concorde, an airliner faster than the speed of sound. The future was envisioned as a realm of continuous innovation in air and space travel, characterized by increasing speed and efficiency. However, half a century later, the ability to reach the moon has been lost, and supersonic commercial flight is no longer a reality. This stagnation extends beyond speed, impacting even the reasonable pace of development in critical areas, as evidenced by the two-year timeline for Lockheed to build a Patriot missile interceptor. This slow pace is detrimental to future progress and national security.

Comparing historical aviation with modern advancements highlights this issue. The Boeing 707 ushered in the jet age, significantly increasing travel speed. Yet, the latest airliner, the 787, launched over 20 years ago, offers no substantial speed improvement. Before Boom, the closest America came to a supersonic airliner was a mere mockup.

The Enduring Allure of Flight

Despite the current state of air travel, the act of flying remains profoundly inspiring. The experience of accelerating down a runway, ascending into the sky, and gaining a "human's eye view" of the world below, all in near-perfect safety, is a testament to human ingenuity. It allows individuals to witness both the beauty of nature and the creations of humanity, riding on the principles of Newton and the Wright brothers while observing the legacies of Edison and Rockefeller. However, this inspiring experience has, for many, become a source of dread.

Historically, air travel was transformative. Early jetliners doubled travel speeds, leading to significant societal changes on the ground. For instance, Hawaii became a mainstream tourist destination only after jet travel reduced flight times from the US to Honolulu to seven to nine hours. The impact extended to other industries:

• Shoes: Phil Knight, founder of Nike, was inspired to start his company in the 1960s after discovering Japanese running shoes during a trip, leading Nike to initially import these shoes to America.
• Music: Before digital streaming, air travel facilitated the globalization of music. The Beatles' first world tour in the late 1960s would have been impractical a decade earlier due to slower aircraft.

Imagining a Supersonic Future

Consider the potential impact of another doubling of speed. What if the Atlantic could be crossed in three and a half hours, or Sydney became as accessible as Honolulu is today? What new "Beatles," "Nikes," or "Hawaiis" would emerge in a supersonic age?

The speaker, in their mid-20s, became captivated by the idea of reviving supersonic passenger travel, setting a lifelong goal to break the sound barrier. Initially, they observed that progress in "supersonic music" (referring to audio technology) seemed to outpace supersonic flight.

The conventional wisdom suggested that supersonic travel would return as a private jet for the ultra-wealthy, built by companies like Gulfstream. However, a major hurdle was the US ban on supersonic flight, a legacy of the Concorde era. Since most Gulfstream flights are overland in the US, a business case for private supersonic jets was weak without regulatory change, and no business jet manufacturer was willing to risk building an illegal aircraft. Boeing, traditionally a leader in airliners, was not pursuing innovative new aircraft, let alone supersonic ones.

The Genesis of Boom

The idea of a startup building a supersonic airliner seemed audacious. In 2015, Jeff Bezos, during a pitch for Boom's seed round, passed on the investment, later writing in Amazon's shareholder letter that airliners were projects only large companies could undertake. The speaker, a software engineer by training with experience at early Amazon and a successful app company acquisition by Groupon, questioned their own ability to tackle such a complex endeavor, their aviation knowledge limited to a pilot's license for a Cessna.

However, they realized that true understanding of one's capabilities comes from pursuing an inspiring mission with unwavering dedication. In 2014, Boom began with an inauspicious start: a supersonic airliner mockup made of cardboard, plywood, and Office Depot seats. Despite initial skepticism and laughter—especially regarding the company name, "Boom," which evoked explosions—they persevered.

Their first prototype, XB-1 (nicknamed "Baby Boom"), was conceived as a learning platform. Recognizing the immense challenge of building a supersonic passenger plane, they aimed to construct the first supersonic jet outside of government or military control to gain essential knowledge.

Breaking the Sound Barrier and Regulatory Hurdles

Last year, XB-1 made history by becoming the first independently developed jet to break the sound barrier, a decade after the company's founding. This achievement, witnessed in the Mojave Desert, marked a significant milestone.

The journey was fraught with challenges. Boom nearly failed multiple times, once reaching a point with only seven days of cash, with the board advising shutdown. The founder's conviction in the importance of their mission propelled them forward through these difficult periods.

XB-1 achieved a radical breakthrough beyond just speed: it addressed the sonic boom problem. During six supersonic flights, no audible sonic boom was detected on the ground. This demonstrated the principle of "Mach cutoff," where breaking the sound barrier at a sufficiently high altitude and optimal speed for prevailing weather conditions causes the sonic boom to make a U-turn in the sky, never reaching the ground. This effectively eliminated the long-standing debate about acceptable noise levels for supersonic flight.

This success had immediate regulatory impact. Within 24 hours of breaking the sound barrier, the team was invited to the West Wing, and 115 days later, an executive order legalized supersonic flight in the US. This demonstrated that regulations in a highly regulated industry can be changed by building and proving the viability of a solution. The bipartisan support for supersonic flight, evidenced by unanimous votes in both the House and Senate committees to permanently legalize it, signals its return.

Innovations in Development and Manufacturing

XB-1 achieved several other firsts:

• The first privately developed supersonic jet, a feat previously exclusive to governments and militaries.
• The first supersonic jet made in America.
• The first human-piloted airplane landed solely on augmented reality, without a natural view of the runway.
• The first supersonic air-to-air live stream, filmed on an iPhone and streamed via Starlink.
• Crucially, it led to the legalization of supersonic flight in the US.

This was accomplished by a remarkably small team of 50 dedicated individuals. The key to this efficiency was making hardware development more akin to software development, reducing the cost of iteration in both the digital and physical realms.

Traditional airplane design is highly integrated, where changes in one area (e.g., adding passenger seats) necessitate extensive redesigns across propulsion, aerodynamics, and structures. This leads to slow iteration cycles, with specialists working in silos and manual handoffs. Boom adopted a different approach:

• Software-driven Engineering: They developed "Makeboom," a system that allows defining an airplane in a configuration file and running whole-aircraft simulations in minutes. This enables rapid evaluation of designs, fuel efficiency, passenger capacity, and trade-offs, helping to identify the optimal supersonic jet for market fit.
• Engine Design: For engine development, they created "Bladeunner," a tool that allows engineers to change blade designs in real-time and instantly see structural and aerodynamic behavior. This reduces a process that previously took months for dozens of engineers to mere moments.
• Vertical Integration in Manufacturing: Recognizing the difficulties of iterating with external aerospace suppliers, Boom built its own machine shop. This allows them to go from a digitally designed engine part to a prototype in about 24 hours, significantly accelerating iteration. This R&D shop is unique compared to larger aerospace companies.
• In-house Testing: They are building their own engine test stand, located near their engineering and manufacturing facilities. This eliminates the need to reserve time in external test cells, allowing for on-demand testing.

Scaling Up and Financing Innovation

As Boom transitions from XB-1 to Overture, their passenger airliner, they are scaling up. They are building a "superfactory" for vertically integrated manufacturing of engines and ultimately airplanes. This factory, which was an empty building six months prior, is now seeing the installation of its first machines and will soon begin producing engine parts.

A major challenge for supersonic airliner development is financing, given the billions of dollars in R&D capital required and the unpredictable timelines. Boom found an innovative solution by vertically integrating their propulsion system. They adapted their supersonic engine for ground power generation, calling it "Superpower." This allows them to sell these turbines separately, generating test data, reliability insights, and crucial capital. The first Superpower turbines are currently under construction and will be delivered to customers within 12 months.

The Importance of Inspiration and Building in Public

The motivation behind Boom extends beyond technological achievement; it's about creating things that inspire. The live stream of XB-1's supersonic flight, the first supersonic Starlink installation and air-to-air live stream, attracted millions of viewers globally, including children in classrooms. This public engagement aims to inspire the next generation of engineers and innovators. Boom believes in "building in public" to foster this inspiration.

Addressing Common Misconceptions and Challenges

The speaker addressed several questions regarding entrepreneurship, technology, and manufacturing:

• Widely Believed Tech Fallacies: The belief that all technologies are created at the earliest possible moment, and that if an idea is good and nobody else is pursuing it, something must be wrong, is false. Many solvable, multi-billion dollar problems remain unaddressed simply because no one has taken the initiative. The technology for supersonic flight existed long before Boom, but no one started the company.
• Competing with China in Manufacturing: America can compete by inventing the next wave of manufacturing rather than trying to repatriate old methods. China's dominance in tool and die manufacturing, for example, can be circumvented by developing entirely digital manufacturing processes that eliminate the need for traditional tooling, as Boom is doing with its turbine blades. America's strengths lie in invention, freedom, and innovation.
• AI's Impact on Physical World Building: AI has dramatically reduced software development costs, enabling the creation of custom engineering tools that were previously unaffordable. This allows businesses to have software perfectly tailored to their operations, similar to how Amazon built its own business software. However, physical world AI, such as programming CNC machines, is still in its early stages, though progress is expected.
• Hiring Practices: In an industry dominated by large, often bureaucratic companies, Boom prioritizes early-career talent who are ambitious, smart, hands-on, and optimistic, and who haven't been "destroyed" by legacy aerospace cultures. For senior roles, promoting from within is preferred to maintain cultural fit.
• Desired Products: The speaker wishes for "physical AI for manufacturing"—large-format manufacturing capabilities that can go from CAD design to automatically quality-assured parts with one machine and no programmer.
• Regulatory Engagement: The approach to regulatory engagement depends on the context. For safety-critical products like aircraft, early and collaborative engagement with regulators is crucial. Boom involved the FAA from the outset, treating them as partners in solving the problem, which led to rapid approvals. This contrasts with approaches like Uber's, which initially bypassed regulators to build a customer base.
• Best Advice Received: Steve Jobs's Stanford commencement address, emphasizing the importance of working on something one loves and not compromising on that passion. The ability to "care" is an unteachable quality that is vital in employees and partners.
• Worst Advice Received: "Work on something you know something about." This advice can lead to working on uninspiring projects. While knowledge and skills can be learned, passion is not easily changed.
• Funding Deep Tech: Boom's long development timeline (10 years to break the sound barrier) was challenging for investors. The speaker advises against following their exact path, suggesting that earlier deep tech companies faced greater uncertainty. Future deep tech startups can learn from Boom's experience by focusing on faster iteration at the product level, starting with simpler prototypes to gain proof points more quickly.
• Advice for 20-Year-Olds: If a startup idea is consuming one's thoughts, pursue it. Otherwise, work with inspiring people on problems that matter to the organization. Early career experiences where one's work is valued and supported by influential figures are transformative.
• Self-Belief: The speaker admits to not having self-belief on day one. It developed by focusing on "how to do it" rather than "if I can do it." Self-doubt is normal, but it must be set aside to become the person needed to succeed.
• Lessons from Early Amazon and Jeff Bezos: Amazon's success stemmed from its ability to think long-term (seven-year plans) while maintaining incredible operational discipline in the present. Bezos tackled seemingly bizarre ideas (AWS, e-commerce) that ultimately proved highly successful. This combination of long-range vision and day-to-day excellence is rare but characteristic of great companies.
• Teaching Yourself Hard Things: It's crucial to distinguish between knowing enough to pass a test and truly understanding a subject from first principles. The speaker meticulously studied aerospace engineering, doing problem sets and maintaining a "confusion list" to track areas needing deeper understanding. This self-awareness of what one truly comprehends is vital for continuous learning.
• Skills for Early Career Technical People in the AI Era: The notion that software engineering is dead is incorrect. AI reduces the cost of software development, increasing the demand for software engineers to manage architectures and ensure coherence. The advice is to focus on being useful, learning how to create things, and being multidisciplinary.
• Young Engineers in Hardware: The idea that hardware requires extensive experience is a "lie told by old people at big dumb companies." Young engineers can stand out by building real things, pursuing hobbies (like RC model airplanes), and learning practical manufacturing. While deep expertise can be limiting, seeking wisdom from experienced individuals is valuable, but ultimately, one must "just go build."
• Starting a Company vs. Working at One: This is not a one-size-fits-all decision. If an idea is compelling and inescapable, start the company. Otherwise, gain experience at a company with great people and meaningful problems. Avoid starting a company just for the sake of it, as it can lead to misery if the passion isn't there.
• Location for Founders: Founders don't need to be in San Francisco, but being in an ecosystem with ambitious people (like SF, LA, Austin) is beneficial for inspiration. Boom moved to Denver for affordable physical world building.
• Hiring College Freshmen/Sophomores: Look for side projects and extraordinary achievements that demonstrate passion and initiative, even without formal work experience.
• Work-Life Balance: The speaker believes in "work-life harmony," where meaningful work is an integral part of life. They emphasize finding work one loves and eliminating "detritus" from one's life. Balancing family and CEO responsibilities is challenging but achievable, with lessons often cross-pollinating between roles.

The overarching message is to build something you love, something that should exist in the world, and to leave the planet better than you found it.