CNMO learned from foreign media that American startup Longshot Space Technologies is developing a giant space cannon with a length of about 10 kilometers, planning to use compressed air to launch satellites and other payloads directly into low Earth orbit. Unlike SpaceX, Blue Origin and other companies that rely on recoverable rockets, Longshot Space uses the principle of "multi-stage gas injection": by continuously detonating compressed gas in a vacuum pipe, the wedge projectile continues to accelerate, and finally leaves the gun barrel at about 23 times the speed of sound (about 7km/s) and enters space.

The core advantage of the system is the extremely low launch cost. The company claims that the launch cost per kilogram of payload can be reduced to $10, while SpaceX's Falcon 9 rocket currently costs about $3,000 per kilogram. To achieve this goal, the team has built a 36-meter-long prototype gun in Oakland, California, capable of accelerating projectiles to more than four times the speed of sound. The next step is to build a larger test facility in Alameda, California, and eventually a ten-kilometer-long official launch device in the Nevada desert.

However, the technical challenges are extremely serious. When traveling through the atmosphere at 23 times the speed of sound, air friction causes the surface temperature to rise above 1650°C and form plasma. To this end, Longshot Space uses mass ablation protection technology: a thick layer of protective material is wrapped outside the payload, and the heat is removed through continuous evaporation of the material at high temperatures, similar to the thermal protection design of reentry aircraft. In addition, the 10-kilometer-long acceleration track can control the peak overload to about 500g (500 times the acceleration of gravity), which is fatal to humans but still bearable for most electronic devices and building materials.

It is reported that the project has received support from OpenAI CEO Sam Altman and the U.S. government. Although the prototype has made initial progress, whether it can be reliably launched on an industrial scale and truly reduce the cost to $10/kg still needs to be verified by follow-up tests.