A Radically Different Approach
Enter Longshot Space, a company with a vision that sounds like it was pulled from science fiction: to fire payloads into orbit using a giant, ground-based cannon. Officially called a kinetic launch system or a multi-injection hypersonic accelerator, the
concept ditches the need for massive, fuel-heavy rockets for the initial, and most energy-intensive, part of the journey. By keeping the primary acceleration infrastructure on Earth, Longshot aims to create a reusable, high-frequency, and dramatically cheaper alternative for getting hardware into space. The company isn't launching people—the immense G-forces would be prohibitive—but is instead targeting the ever-growing market for commercial and government satellites.
How the 'Space Gun' Works
Instead of chemical combustion, Longshot’s system uses compressed gas to propel a payload down a very long tube. The key innovation is a technique called “side injection” or “multi-injection.” Rather than a single massive blast at the start, precisely-timed bursts of gas are injected through ports along the barrel, repeatedly pushing the projectile and steadily increasing its speed. This allows for a gentler, more controlled acceleration compared to a traditional cannon, which is crucial for payload survival. The company has already conducted over 100 test firings with a 120-foot prototype in Alameda, California, accelerating payloads to speeds greater than Mach 4.
The Economic and Strategic Advantage
The primary driver behind this technology is cost. While a conventional SpaceX Falcon 9 launch can cost around $3,000 per kilogram, Longshot's CEO, Mike Grace, believes their system could eventually bring that cost down to just $10 per kilogram. This is achieved by eliminating the need to lift tons of rocket fuel and complex engines against gravity. The accelerator itself can be built with more common materials like steel pipe, similar to what's used in natural gas pipelines, further reducing expense. This disruptive cost model has attracted significant attention, including from investors like Sam Altman and South Park Commons, and the U.S. Department of Defense, which sees potential for high-frequency, low-cost hypersonic testing.
From Hypersonic Testing to Orbit
Reaching orbit requires incredible velocity—around Mach 25. Longshot's current prototype has achieved Mach 4, so there's a long way to go. The company's strategy is phased. The first commercial market is hypersonic testing for defense and aerospace clients. By building a longer accelerator—a 1,600-foot version is planned for a site in Nevada—they can offer a repeatable and affordable platform for testing vehicles and materials at speeds exceeding Mach 5. Revenue from this business is intended to fund the ultimate goal: an orbital launch system. This final version would require an accelerator stretching up to 15 kilometers (over nine miles) long.
Challenges on the Horizon
The ambition of Longshot's plan is matched only by its technical challenges. Scaling the technology from a 120-foot prototype to a 15-kilometer orbital launcher is a monumental engineering task. Payloads must be specifically designed and hardened to withstand the high, albeit controlled, G-forces of a kinetic launch. This means satellite manufacturers would need to adapt their designs to fit the system. Furthermore, there are significant regulatory and environmental hurdles to clear, from land-use permits for a massive installation in a remote area to managing the sonic booms from frequent launches. Competitors like SpinLaunch are also exploring similar kinetic launch concepts, creating a competitive landscape for this new frontier.
