In your time as an engineer, you collected experience from a range of large US aerospace companies including Blue Origin, Lockheed Martin, Sierra Nevada. How is Stratolaunch different from your previous ventures?
It was an exciting opportunity to join a company at its inception and help shape their engineering department and capabilities, aiming for a leadership position in air launch. Initially, the focus was on launching satellites via air launch, which offers advantages over traditional fixed-based launch pads. With the world's largest airplane by wingspan, we could conduct multiple launches from a single aircraft flight, reaching a variety of locations, something that had never been done before. This was a unique engineering challenge that drew me to the company.
After our founder Mr Paul Allen's passing, the market shifted towards smaller launchers. Initially, there was a need for large rockets, but with the trend towards disaggregation—splitting satellite capabilities into multiple smaller satellites—the demand for smaller launchers grew. This shift led to Stratolaunch's transition under new ownership by Cerberus Capital Management, which recognized the emerging need for hypersonic flight testing. Our current focus is on developing hypersonic technology to advance the state of hypersonics in the United States, aiming to leap ahead in capabilities.
How far are we away from seeing hypersonic travel in commercial applications?
Hypersonic refers to speeds five times the speed of sound or more. It opens up various possibilities, such as rapid cargo transport in emergency situations or having a business meeting in Japan and returning on the same day. Hypersonic technology also has significant military applications. Unlike traditional systems, hypersonic systems can manoeuvre in the atmosphere, allowing them to target multiple locations within a single flight, making them more versatile for defense applications.
We're about a decade away from hypersonic business jets due to the rigorous certification process required for carrying passengers. The certification process ensures safety in different scenarios, such as engine failures or landing gear issues. It takes around five to seven years to complete a healthy certification process, which makes the timeline realistic but ambitious. There are others demonstrating hypersonic capabilities, but not in the same manner as we do. The U.S. Department of Defense aims to conduct hypersonic flight tests weekly, yet we’re currently only seeing tens of such flights per year compared to their target of 50. So while there are others in this space, there's room for multiple players to contribute to this field.
Given the immense amount of power necessary for hypersonic speeds, what does factoring sustainability into hypersonic engines and flight look like?
Current advanced engines are still air-breathing, similar to traditional aircraft engines, meaning they carry fuel and intake air during flight. There’s potential to transition to more sustainable fuels, such as those derived from bio sources, to reduce reliance on fossil fuels. This transition will require design adjustments, like longer wings or larger fuel tanks, to optimize efficiency. The fuel burn is a bit more efficient than on an airliner, but the distances covered are extensive.
We’re still talking about thousands of gallons for a single hypersonic flight. If hypersonic travel becomes frequent, it will demand a substantial supply of sustainable fuels, presenting a challenge in production. We’re considering how to incorporate sustainable fuels into our designs. Although such fuels don’t currently burn as efficiently, design modifications—such as longer wings or larger fuel capacity—can help compensate. We aim to adapt our designs to be compatible with emerging fuel technologies.
Given the lessons learned from the Concorde's, are you concerned about similar challenges with hypersonic travel, especially regarding safety and cost?
From a safety perspective, we've learned a lot from the Concorde and other aviation incidents. Incorporating safety measures like redundancy and robust design ensures we’re addressing potential failure mechanisms. Following an established certification process is critical to ensuring safe operation, and we’re committed to that. Materials science is also a key enabler. In the past, we didn’t have the capability to build materials that could withstand the heat generated at hypersonic speeds.
Now, advanced materials and additive manufacturing techniques allow us to form these materials into shapes that are both strong and heat-resistant, which is crucial for sustained hypersonic flight. Internally, hypersonic flight presents challenges such as intense vibrations and heat, which require rigorous testing. Externally, the time scale of reactions is much faster, meaning control surfaces must respond quickly to disturbances like turbulence. We prepare for these challenges through thorough design and testing.
What do Stratolaunch's launch plans and roadmap look like for the next couple of years?
We’re focused on demonstrating reusable hypersonic flight, aiming to turn around vehicles for repeated flights. Our goal is to reach one flight a month by the end of 2025, and we'll start utilizing our 747 Spirit of Mojave aircraft as a secondary launch platform, which means we’ll have two launch platforms for hypersonic vehicles by then. Most launches occur in our backyard in Mojave, California, in collaboration with Space Launch Delta 30 and the Point Mugu Sea Range. We’re also exploring other locations, particularly as part of the Department of Defense's Multi-Service Advanced Capability Hypersonics Test Bed (MACH-TB) program, which aims to expand hypersonic testing to various sites.
To date, the most significant ‘wow moment’ would be our first high supersonic flight on March 9th, 2024. Seeing the vehicle release, the engine ignite, and achieving Mach 1 and beyond was incredible. It wasn’t just about the achievement; it was the culmination of our team's efforts and the rewarding feeling of seeing our hard work pay off.
