SpaceX’s Missed Opportunity: A Thought Experiment
SpaceX’s Starship progression: could an intermediary step have made a difference?
Space exploration and innovation have always been met with extreme reactions and SpaceX, under the leadership of Elon Musk, is no exception. As SpaceX continues to push the boundaries of space technology, the public opinion is divided: one group staunchly believes in Musk’s every endeavor, while another remains skeptical about the company’s future trajectory.
The Starship Debate
The Starship project encapsulates this division. On one hand, enthusiasts predict Starship will soon be delivering substantial payloads multiple times daily at an incredibly reduced cost. Detractors, however, are not as optimistic, believing that the Starship might not even see operational status within this decade.
Between these polarizing views, there lies a moderate perspective. This group, of which I resonate with the most, anticipates that the Starship will likely become operational by mid-decade. Its cost per launch may still exceed that of SpaceX’s current Falcon 9 Block 5 launch vehicle when considering the overall price, but perhaps if the company can achieve their desired launch cadence, we may be able to break the cost per launch down to a per unit of mass to orbit basis; here is where it’s expected to be more efficient.
The Development Path Dilemma
SpaceX’s decision to simultaneously incorporate several groundbreaking technologies into the largest launch vehicle ever conceived raises eyebrows. Skepticism grew after seeing challenges in areas like ground support equipment, bureaucratic hurdles, and opposition from environmentalists. This “giant leap for mankind” that SpaceX is taking on seems to be akin to NASA going from the Titan-II, which carried the Gemini capsule, to Apollo and Saturn V in a single step. However, NASA went through an iterative development cycle that scaled from the Saturn I, to the Saturn IB, and then the Saturn V. Each iteration tested a different aspect of the end goal, from launch infrastructure and upper stage structural design to manufacturing processes and propulsion systems. This prompts us to reflect: could a different developmental sequence have been more effective for Starship/Superheavy?
It’s worth pondering over a hypothetical scenario: What if SpaceX had introduced an intermediary vehicle before the Starship? Let’s envision a Falcon 9-esque design powered by Raptor engines, the FalconR. If the Raptor engine is indeed superior to the Merlin in thrust and efficiency, this FalconR hybrid could theoretically deliver more payload at a reduced cost than the Falcon 9 Block 5. A single first-generation Raptor engine could produce a little over double the thrust with an improved efficiency of 15%. Moreover, if the Starship is indeed more cost-effective than the Falcon 9, this hybrid could potentially reduce launch costs significantly while giving SpaceX the ability to explore Starship/Superheavy technologies.
The Benefits of a Precursor
Had SpaceX pursued this intermediary step, several advantages might have surfaced:
- Accelerated Testing and Deployment: Test flights for the Starship could have been replaced by tests for this hybrid FalconR, leading to operational missions commencing much sooner.
- Efficient Construction: The smaller diameter launch vehicle would result in quicker and more resource-efficient construction phases. The earlier welding challenges faced by SpaceX might have been mitigated had they incorporated stainless steel structures into this FalconR (although this would be a much larger design change further from just a Falcon 9 upgrade).
- Regulatory Ease: The colossal size of the Superheavy-Starship combo has raised concerns. A smaller hybrid might have been perceived as a logical progression from the Falcon 9, potentially simplifying regulatory approvals and the pad infrastructure challenges faced during Star Base development and Starship testing.
- Improve Raptor Reliability: One of the biggest issues we’ve seen with the first Integrated Flight Test and even with Superheavy static fires (especially during the early development stage) has been the reliability of the Raptor engine in its clustered operating configuration. Starting with a four or five engine FalconR hybrid could get operational flight time on those engines and improve the development feedback cycle.
However, it is important to note that this path does not come without its inherent risks. For one, redesigning an existing system to use a different propulsion configuration is not very straightforward and this design “repurposing” would require a lot of rework to accommodate the Methalox (liquid methane and liquid oxygen) propellants at the necessary propellant ratios for the Raptor engine. This is complicated further if stainless steel structures were implemented making this a completely new vehicle anyway. Additionally, this would mean that the FalconR would not be able to take advantage of SpaceX’s existing launch pad infrastructure at Vandenberg and KSC without its own rework. Finally, and perhaps most importantly, questions arise if SpaceX could have been as competitive with their NASA Human Landing System proposal if they started with a FalconR launch vehicle. At the time of their proposal, they were already conducting Starship launch and landing tests, with successful milestones accomplished at the time of the contract award. So, this brings us to perhaps a better intermediate step alternative.
A Larger Intermediate Design, Starship Prime
Building on the FalconR concept, there’s potential for an even larger intermediate vehicle that would provide more benefits to the SpaceX development process for Starship/Superheavy with fewer of the drawbacks. What if SpaceX went with a launch vehicle akin to Vulcan Centaur and New Glenn?
This vehicle, with a diameter of 5.4m and dubbed “Starship Prime”, presents a compelling middle ground between Falcon 9 and Starship/Superheavy at 3.4m and 9m respectively. A vehicle of this size would also be able to compete with Blue Origin’s New Glenn launch vehicle due to the power, size, and efficiency that the Raptor engines provide over Blue Origin’s BE-4 engine.
Starship Prime would not only address launch vehicle payload volume concerns but also provide a platform to refine technologies and processes at a larger scale. Unlike the FalconR, this vehicle would be designed from scratch, drawing directly from Starship and Superheavy concepts. This means the incorporation of the stainless-steel design that Starship/Superheavy is well-known for today. It also provides a good starting point for development and refining the structural manufacturing of Starship/Superheavy. The infrastructure needed for such a vehicle, including the ground support equipment (GSE) and launch systems, could be designed with the future in mind, ensuring they are either compatible or easily adaptable for the larger full-scale system. In essence, Starship Prime would act as a bridge, not just in size but in the incorporation and testing of technologies intended for the grander vision.
Moreover, it could cater more effectively to projects like Starlink V2, bridging the gap until the Starship becomes operational. A 5.4 m vehicle, assuming a payload to orbit capability between Vulcan Centaur and New Glenn, would be able to launch somewhere on the order of 40–50 Starlink V2 Mini satellites, more than double what Falcon 9 Block 5 can currently achieve.
Market Limitations
I think the best argument, aside from the perceived development improvement from a Starship Prime launch vehicle, is based on the current launch market limitations. The full-scale Starship’s size is certainly inspired by the grandeur of large-scale human Mars missions; however, the current market for such a massive vehicle seems significantly limited from a business perspective. The satellite market, which one would assume to be a primary customer, has shown signs of saturation. SpaceX has already experienced this with the Falcon 9, having to scale back their initial launch cadence plans due to the market’s inability to provide enough satellites for launch. In fact, despite Falcon 9 launching more than 9 times the launch mass as their next competitor (CASC), SpaceX remains its own largest customer by far using their Starlink constellation to bridge the gap in operations (Starlink accounts for almost 60% of Falcon 9 missions in 2023). If Falcon 9 faces such constraints, the much larger Starship might encounter even more pronounced challenges with even fewer commercial customer missions a year for the foreseeable future.
There’s obviously a distinct difference between a vision and a viable business plan. Elon Musk’s dream of colonizing Mars, while laudable, doesn’t immediately translate into a profitable enterprise for the Starship. The economic realities of space exploration are harsh, and until there’s a clear, sustained demand for Mars missions or similar large-scale endeavors, the Starship’s market potential remains uncertain. The NASA HLS contract certainly helps, but it isn’t immediately obvious to me that a 5.4m or similar launch vehicle couldn’t still fit the role and concept of operations the Starship/Superheavy HLS vehicle is designed to do today (it already far exceeds NASA’s requirements for a lunar Human Landing System vehicle).
The Course Ahead
SpaceX’s Starship project represents a significant leap in the realm of space technology, showcasing the company’s ambition to push boundaries. However, the complexities and challenges of such a groundbreaking endeavor suggest, at least historically, that a more incremental approach could be beneficial. Exploring intermediate vehicles could allow SpaceX to refine critical technology elements while better aligning with current market demands. This approach has been repeatedly adopted; even the United Launch Alliance employed it with its soon to launch Vulcan Centaur launch vehicle.
I’ve closely followed and admired SpaceX’s progress over the years. It’s vital to recognize that every path in space system design comes with its unique advantages and drawbacks. While this article presented a thought experiment based on my own experiences and observations, it was crafted with a deep appreciation for SpaceX’s achievements and the inherent challenges they face. I strived to be fair to the known facts and understand the multifaceted aspects of every decision. At the end of the day, it’s a joy to witness SpaceX’s journey, and I wholeheartedly look forward to what the future holds for them.
As the upcoming Starship flight tests loom, the broader space community will be keenly watching. The choices SpaceX makes now will not only influence their future but potentially set the trajectory for space exploration in the coming decades as Starship launches operationally.
