Expandable Rocket Architecture Paving The Road For Deep Space

Most probably many people have been asking why I keep developing radical rocket designs rather than sticking to the ones established more than half a century ago. My argument is simple: those traditional designs have reached their limit. We need to be able to build much higher payload capacity rockets than Saturn V and Starship. This is an absolute necessity if we want to expand human space exploration beyond the Moon.

You cannot send humans to deep space missions on the least-energy ballistic trajectories optimized for robotic explorations. I believe that as the human deep space mission duration increases, its probability of failure increases exponentially. This requires us to send multi-stage rockets to deep space that allow continuous acceleration on the outbound trajectory and active deceleration before entering orbit or landing. The same acceleration-deceleration profile copies to the return flight as well.

The payload mass is only one part of the story. The other is the capability for rapid, heavy launches. For example, for a Mars mission, the return-to-Earth module should be sent independently of the landing module. This split-mission architecture lowers the stage count and the maximum payload mass needed for any single launch. However, frequent, heavy launch capability is a absolute must in this case.

My previously proposed naked ultimate rocket fulfills these criteria perfectly. By strapping coupled (Fuel + Oxidizer) propellant tanks around a perimeter, the rocket’s launch capability becomes highly expandable. You can arrange these standardized tanks in concentric rings around a hollow center opening. Because the payload sits protected inside this center void, the structural hull doubles as the cargo bay, completely eliminating the dead weight and complexity of a traditional nose-cone fairing.

Coupled with a direct ascent trajectory and a three-stage launch profile, heavy rockets can be scaled up without increasing vehicle heights to skyscraper levels. We cap the height at around 100 meters, expanding horizontally instead. Distributing the total flight load across three stages rather than two allows the massive thrust and structural requirements to be divided into smaller, more manageable increments. This structural optimization dramatically increases the final payload capacity, as the vehicle avoids carrying the dead weight of a massive, single upper stage deep into the ascent. Wider rockets have a much lower center of gravity; they are easier to handle on the ground, highly resistant to wind shear, and fundamentally more stable during flight.

This radial-only expansion completely redefines manufacturing scalability. Building ever-larger singular monolithic tanks—like the path taken by Starship—forces the industry into a cycle of constant redesign, requiring massive new tooling, giant vertical assembly hangars, and custom transport logistics for every increase in scale. In contrast, my cascading architecture of smaller tanks slashes design cycle times and maintenance costs to a bare minimum. To build a rocket with higher payload capability, we do not design a new vehicle; we simply add more standardized tank modules to the outer rings. Because the rocket height remains strictly fixed at 100 meters, the launch pad infrastructure remains completely standardized. The ground facilities never need to be rebuilt or modified as the vehicle's capacity grows horizontally.

Splitting the volume into independent, small-diameter tanks also solves the fluid dynamics problem. Instead of a giant monolithic tank where low-frequency fluid sloshing can destabilize the vehicle, the small-diameter tanks act as built-in vertical bulkheads. The fluid mass is partitioned, making sloshing self-dampening and predictable without heavy internal baffling.

This setup allows the first stage to be recovered without a high payload penalty, while the other two vacuum-optimized stages are expended. The first stage—which is the heaviest and most expensive part of the stack—is recovered, drastically lowering the financial overhead of the launches.

Instead of complicating the rocket itself, I prefer to shift the complexity to the launch site and ground operations. The independent tank arrangement enables a decentralized ground fluid matrix where each tank is filled individually and simultaneously. While this complicates the pad's plumbing setup, the total on-pad fueling time is considerably reduced. More importantly, it eliminates the need for immense, heavy high-power turbopumps inside the rocket itself, as the engines are fed directly by their immediate adjacent fuel-LOX tank pairs via short, localized run lines.

Reliable and gentle operation of the first stage allows it to be serviced rapidly and readied for the next flight quickly, mimicking the turnaround of commercial aircraft at airports. This operational loop unlocks the rapid, heavy launch frequencies required to establish permanent infrastructure across interplanetary space. By freezing the vertical dimension and scaling horizontally, this architecture shifts spaceflight from custom, low-frequency exploration to a high-throughput industrial logistics network.