Ultimately, it's still about criticizing China's rocket recovery capability as being too weak to compare with Falcon 9, calling the entire recovery effort nothing but unnecessary overcomplication! Here's the situation: On X, the account "Groundhog Diary" posted a lengthy comment on the topic of net-based recovery that was one-sided and biased, which netizens in the comment section quickly seized upon, leading to a scathing and satisfying rebuttal!

"Groundhog Diary" claims to have worked at CALT (Caltech) for 20 years and in China's commercial space industry for 5 years, positioning themselves as an insider in the aerospace field. Their commentary on Chinese aerospace has generally been positive—but in this particular article, they clearly let personal bias slip through.

The article argues that aside from differences in landing methods, the biggest distinction between current U.S.-China recoverable rockets lies in SpaceX’s ability to perform "return-to-launch-site landings." Let's clarify: the article doesn't delve into the technical system behind net-based recovery; instead, it mainly discusses flight trajectories during rocket recovery.

Falcon 9 rockets can achieve both ocean-area vertical landings and return-to-launch-site vertical landings. In contrast, China’s Long March 10B can only perform ocean-area landings. The author contends that China is not yet ready for return-to-launch-site landings, arguing that such a feat isn’t merely about relocating the landing site to land—it requires extensive logistical support.

The reason for choosing ocean-area landings stems from the fact that rockets don’t launch straight up vertically, but rather fly roughly along the orbital inclination toward the south. After completing their mission and separating, the first stage is already far from the launch site. Thus, recovery vessels typically wait at the terminal point of the first stage’s parabolic descent trajectory.

At that point, the rocket naturally falls, adjusts its attitude, uses retro-thrust to decelerate, and performs a vertical landing—this method saves the most fuel! The Long March 10B currently employs exactly this approach. Besides ocean-area vertical landings, Falcon 9 can also return to the launch site for recovery—essentially retracing its path from beyond the apogee back to a landing zone near the launch site.

This advantage eliminates the need for a recovery ship to travel to a specific location, but comes with greater difficulty: returning from over 400 km away while decelerating requires multiple engine ignitions and shutdowns, imposing significantly higher demands on telemetry control, navigation accuracy, and overall technical complexity compared to ocean-area landings. Therefore, the author concludes that China’s Long March 10B cannot currently achieve return-to-launch-site landings.

Hence, the conclusion drawn is: “Return-to-launch-site” recovery imposes higher flight control requirements, whereas “ocean-area unmanned vessel legged recovery” involves greater engineering and mission constraints; both “ocean-area land recovery” and “ocean-area unmanned vessel net-based recovery” impose relatively lower demands on flight control and engineering.

From the standpoint of the author’s viewpoint, there’s nothing fundamentally wrong—but the conclusion is drawn prematurely. How should we put it? From the perspective of recovery technology, China is like a genius high school junior solving an exam’s final, most difficult problem using an entirely new approach. Then someone tells them: “This problem could’ve been solved instantly using Taylor expansion—why make it so complicated?”

The advice isn’t flawed—but shouldn’t the person be given some time? After all, the author didn’t mention some bizarre early operations by SpaceX, such as Falcon 9 initially being recovered at sea only to require workers to climb aboard and weld it in place because it couldn’t be secured. While such practices were never standardized later, SpaceX dared to do it right from the start!

For China’s aerospace industry, this would be an absolute red-line violation: the rocket hasn’t released residual propellant after landing, and neither the liquid oxygen nor kerosene tanks have been depressurized. Any tipping over could lead to catastrophic consequences. China absolutely wouldn’t take such risks! That’s why they’re willing to spend heavily on building an autonomous recovery vessel—the "Pilot No. 1"—a fully automated, uncrewed ship designed specifically to safeguard lives.

It’s worth noting that many people may not realize this fully automatic, crewless vessel is precisely China’s way of leveraging its financial and technological strength to build safety-critical infrastructure.

The article failed to highlight the key advantages of China’s recovery approach or acknowledge SpaceX’s own unconventional recovery practices. Although the argument appears fairly balanced on the surface, when compared side-by-side, it reads like a subtle case of “writing with a moralizing tone.” As a result, the comment section was quickly set off—many netizens mocked China’s recovery rockets sarcastically, but others argued that China’s technology enhances reliability, reduces deadweight, and increases payload capacity.

However, one viewpoint transcended the technical blind spots of supporters of China’s recovery rockets. A foreign netizen followed the thread logically and concluded:

Remove the landing legs—adding several tons of dead weight—and don’t even attempt Falcon 9’s payload performance. If you want to use landing legs for touchdown, and further add return-to-launch-site recovery, how much effective payload will remain? While acknowledging the originality of this approach, one must also recognize that China’s rockets and rocket engines still suffer from low efficiency.

We must admit this perspective reflects part of the truth: Falcon 9 has a liftoff mass of 549 tons and delivers 17.5 tons to LEO; China’s Long March 10B has a liftoff mass of 760 tons and delivers 16 tons to LEO. These figures are basically accurate—there’s no need to fabricate data. If our payload is inferior, let’s just admit it openly!

But we must clarify: the Long March 10B is essentially a reuse of leftover components from the Long March 10A—the main rocket intended for future Chinese human spaceflight missions. According to China’s aerospace standards, manned launches currently won’t use recoverable rockets, and there are no plans to convert the Long March 10B into a crewed vehicle in the future.

Therefore, the Long March 10A includes substantial safety redundancies—from engine design to structural integrity—all due to crewed mission requirements, including a 5-meter diameter core stage. The two rockets exist on completely different levels! Falcon 9 dares to use recoverable rockets for crewed missions and even incorporates automotive-grade chips in its systems. China’s aerospace industry simply hasn’t reached that level yet. SpaceX’s choices are theirs alone—but China certainly won’t follow suit anytime soon.

China’s future mainstay for commercial space launches will be the Long March 10C (CZ-10C)—a 5-meter-diameter core stage with boosters—targeting a LEO recovery capacity of 22 tons and a liftoff mass of 940 tons. You might wonder why it’s still so heavy? Because this rocket follows the liquid oxygen-methane propulsion route.

Methane has significantly lower energy density than liquid oxygen-kerosene, resulting in substantially increased structural weight. Why use liquid oxygen-methane then? Because kerosene tends to coke in rocket turbopumps and combustion chambers—extremely detrimental to reusability, requiring more frequent maintenance or part replacements. Methane has almost zero coking tendency, making it the preferred choice for future recoverable rockets!

Original source: toutiao.com/article/1870655137240064/

Disclaimer: This article represents the personal views of the author