The Next SpaceX is… This Giant Space Cannon?

Key Concepts

• Kinetic Space Launch: A method of launching payloads into orbit using mechanical acceleration (a "space gun") rather than traditional chemical rockets.
• Multi-Injection Accelerator: A system that uses a series of pressure vessels along a barrel to sequentially inject high-pressure gas, maintaining acceleration for the projectile.
• Burst Discs: Frangible seals that rupture at specific pressures to release gas into the barrel with millisecond-level precision.
• G-Loading: The gravitational force experienced by the payload; the company aims to keep this under 1,000 Gs to ensure electronic survival.
• Hard Tech/Infrastructure Approach: A design philosophy prioritizing low-cost, robust materials (mild steel, concrete) and custom, low-cost engineering solutions over expensive, off-the-shelf aerospace components.

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1. The Technology: How the Space Gun Works

The system functions as a massive, multi-stage gas accelerator.

• Mechanism: A projectile is placed in a barrel equipped with a series of pressure vessels filled with high-pressure hydrogen. As the projectile passes each set of vessels, burst discs rupture, flooding the barrel with gas to provide continuous acceleration.
• Physics Constraints: The speed of the projectile is limited by the speed of sound in the propellant gas (hydrogen’s speed of sound is ~1,270 m/s). Pushing a projectile faster than the gas results in diminishing returns on pressure.
• Performance Targets: To reach orbit, the system must achieve an exit velocity of approximately 8.5 km/s to account for a 1 km/s loss due to atmospheric drag, ultimately reaching an orbital speed of 7.5 km/s.

2. Engineering Philosophy and Methodology

The team at Longshot Space emphasizes a "first principles" approach to hardware:

• Cost Reduction: By utilizing infrastructure-grade materials (mild steel and concrete) rather than aerospace-grade alloys (Inconel/Titanium), they aim to reduce launch costs to under $100/kg, potentially reaching $10–$50/kg.
• Custom Solutions: Instead of purchasing expensive, specialized components, the team builds their own. A notable example is a high-power electrical feed-through for a pressure vessel: they replaced a potentially multi-thousand-dollar component with a $5 Home Depot NPT fitting, a copper rod, and epoxy.
• Iterative Simulation: The co-founders used simulations to prove that a 15-km barrel length was physically viable, overcoming initial skepticism about the system's required scale.

3. Addressing Challenges: G-Forces and Survivability

A primary concern for kinetic launch is the survival of the payload under high acceleration.

• Evidence: The team cites SpinLaunch’s experiments, which demonstrated that standard satellite components (like momentum wheels) can survive 10,000 Gs.
• Robustness: The speaker notes that modern consumer electronics (like cell phones) routinely survive hundreds of Gs during accidental drops. By designing for <1,000 Gs, they believe most satellite electronics will remain functional without significant modification.
• Trade-offs: If a payload requires extra reinforcement (e.g., gussets on solar panels), the 10–15% increase in mass is considered an acceptable trade-off for the massive reduction in launch costs.

4. Historical Context and Market Evolution

• Legacy Projects: The concept dates back to Jules Verne, with serious 20th-century attempts like Project HARP (1960s) and SHARP (1980s/90s).
• Why Now? Previous projects failed to gain traction because there was no commercial space industry. Today, the rise of the commercial space sector (SpaceX, CubeSats) has created a market where the marginal cost per kilogram is the primary driver of economic viability.

5. Strategic Vision: The "Space Tug"

Because the space gun is a fixed-angle launcher, it cannot easily target every orbital inclination. The company proposes a "space tug" solution:

• The gun launches payloads into a base orbit.
• A fleet of reusable, chemically-fueled space tugs—refueled cheaply via the gun—then transports the payloads to their final, specific orbital destinations.

6. Notable Quotes

• "Funding is negotiable; solar pressure is not." — Highlighting the necessity of solving the physics before worrying about the capital.
• "We are like this whole system is an infrastructure project disguised as an aerospace project." — On the use of mild steel and pipeline-industry materials.
• "If you're doing it right, I think it's not glamorous, at least not early on." — On the reality of the startup grind.

7. Synthesis and Conclusion

Longshot Space represents a shift from traditional, high-cost rocket development to a "hard tech" infrastructure model. By treating space launch as a physics problem rather than a procurement problem, they aim to commoditize access to orbit. The core takeaway is that for deep-tech ventures, success relies on building an "existence proof"—demonstrating that the physics are not impossible—and maintaining the grit to survive the long, unglamorous development cycle before the technology becomes commercially viable.