Zhuque 3 was successfully launched and recovered, and China’s first stainless steel launch vehicle was unveiled

On August 19, after the Zhuque-3 carrier rocket was launched from the Dongfeng Commercial Aerospace Innovation Test Zone, the first sub-stage successfully landed at the predetermined location at the recovery site. This is China's first launch vehicle to successfully enter orbit and be recovered on land.

It is worth mentioning that the Zhuque-3 launch vehicle also has a very "down-to-earth" feature - China's first stainless steel launch vehicle. Its original color of stainless steel is completely different from the classic white paint in people's minds.

For a long time, traditional launch vehicles at home and abroad have generally used aluminum alloy to build their rocket bodies. One of the major advantages of aluminum alloy is its lightweight, which can effectively reduce the weight of the rocket and improve its carrying capacity. This is especially important for disposable launch vehicles. However, when rockets shift from "single throw" to "reuse", there are more factors to consider, such as high temperature resistance, maintainability, etc.

In this context, stainless steel is becoming the “new favorite” of commercial rocket companies. The US Space Exploration Technology Company (SpaceX)'s heavy-lift launch vehicle "Starship", the US Relativity Space Company's (Relativity Space) next-generation large launch vehicle "Terran R", and the German commercial rocket company RFA all use stainless steel as the rocket body material.

According to the relevant person in charge of Blue Arrow Aerospace, in reuse scenarios, stainless steel materials have unique advantages in terms of cost and processability, high and low temperature performance, and maintainability after recycling.

The price is affordable. The price of high-strength stainless steel is only 1/5 of that of aluminum alloy. If the processing and manufacturing costs are also considered, its cost advantage will be even more obvious.

The craftsmanship is mature. Stainless steel has achieved large-scale industrial production and application, and the supply is sufficient; its storage tanks are easy to process and manufacture, and the manufacturing cycle is short, which is conducive to mass production and manufacturing.

Save materials. Stainless steel storage tanks have fewer process steps and are quick to manufacture, and can achieve the effect of "ready to use after uncoiling, cutting and welding". Directly using cold-rolled sheets for coil welding can achieve a raw material utilization rate of 80%.

Easy to repair. Reusing a launch vehicle requires multiple trips to space. The ease of welding of stainless steel makes it easier to repair the rocket after it is recovered.

Good heat resistance. When the rocket returns, it needs to withstand high-temperature ablation of thousands of degrees Celsius and huge aerodynamic pressure. Stainless steel has better high temperature resistance and is less prone to thermal damage when passing through the atmosphere.

Industry insiders believe that using stainless steel to build rockets is not a "material downgrade", but a rational choice made by private aerospace companies in the pursuit of reliability and economy. It is also a pragmatic exploration by private aerospace companies of using cheaper materials to make more durable rocket bodies.

Reporter: Ma Shuaisha