Now the whole country is paying attention to the situation of Shenzhou 20, this time, China has prepared for the worst case, that is, Shenzhou 22 will be launched urgently, and China will create the fastest space rescue record in the world.
Many people are very curious, why can a small space debris cause such serious impact on spacecraft.
The Impact of Small Debris on Spacecraft
There are a large number of space debris in low Earth orbit. They are waste left by humans in space, including the rocket bodies and satellite bodies that have completed their missions, rocket exhaust, discarded objects during space missions, and fragments from collisions between space objects. The size of the debris ranges from micrometer level to meter level.
In fact, although larger debris is manageable, for space debris larger than 1 cm, it is possible to give early warning through on-orbit debris monitoring and take active protective measures. The most troublesome are small debris particles caused by solid rocket engine ignition, certain space experiments, collision of large debris in orbit, peeling off of spacecraft surface materials, and splashing after debris collides with spacecraft. These debris are mostly below 1 cm and difficult to monitor.
On the orbit, debris usually moves at speeds of several kilometers per second (for example, the speed in low Earth orbit can reach 8 kilometers per second). According to the kinetic energy formula (kinetic energy = 1/2 × mass × velocity squared), even debris with a mass of just a few grams has extremely high kinetic energy. For example, a 1 cm metal fragment with a mass of about 0.001 kg, when colliding at a speed of 8 km/s, can have a kinetic energy of up to 32,000 joules, which far exceeds the kinetic energy of a bullet, enough to penetrate the spacecraft's hull. This high kinetic energy concentrated on a small area creates extremely high impact pressure and temperature, causing local melting, vaporization, or fragmentation, possibly damaging key components such as fuel tanks, electronic systems, or life support equipment.
For example, the damage to the external cooling loop of the Russian "Soyuz MS-22" spacecraft in December 2022 and the "Progress MS-21" cargo spacecraft in February 2023 resulted in complete leakage of the coolant, making the spacecraft lose its temperature control capability and ultimately leading to mission failure. Secondly, the puncture itself can cause cabin depressurization, threatening the astronauts' lives. More dangerously, the collision may generate high-temperature plasma and a large amount of secondary debris, forming new threats inside the cabin or near the spacecraft.
Even millimeter-sized debris can have significant destructive power. For example, the International Space Station's robotic arm and portholes have found damage pits or cracks caused by micro-debris impacts. These damages can cumulatively reduce the structural integrity, affect the transparency of the portholes, or reduce the lifespan of mechanical parts.
Comprehensive Assessment of Shenzhou 20
Now, ground personnel are assessing the condition of the Shenzhou 20 spacecraft together with the astronauts. The re-entry capsule is the most critical part, as it is the "vehicle" the astronauts use to return to Earth after completing their mission, which can be considered the "cockpit and safety cabin" of the entire spacecraft. Its outer layer is a special heat-resistant material called the "heat shield." This material is designed to resist the thousands of degrees of heat generated by friction with the atmosphere during re-entry. If this "armor" is damaged in space, even just a small pit or crack, it could allow the high-temperature flame to enter the cabin during re-entry, resulting in catastrophic consequences. Therefore, the intactness of the re-entry capsule is the lifeline for ensuring the astronauts can safely return home, and it is the top priority in the assessment.
Another extremely dangerous part is the spacecraft's propellant tank and the connected pipelines and engines. They are like the spacecraft's "fuel tank" and "power system." The spacecraft adjusts its attitude, changes orbit, and even returns to Earth, all depend on these engines firing accurately to provide power. If a high-speed debris pierces the tank shell, causing fuel leakage, the spacecraft may lose power like a car without fuel, becoming uncontrollable. Even more dangerous is that if certain fuels leak into the vacuum environment, they may rapidly vaporize or trigger other complex reactions, directly threatening the structural safety of the spacecraft. Therefore, the sealability and integrity of the propulsion system directly determine whether the spacecraft can "start" and "return" when necessary.
At times, the astronauts may need to go outside the spacecraft to inspect the Shenzhou 20. Sometimes, the damage might not be visible to the naked eye, but the stiffness and strength of the components might have changed. All these require thorough assessment by ground personnel before conclusions can be drawn.
If it is assessed that the Shenzhou 20 is unsuitable for carrying astronauts back, then our Shenzhou 22 will be launched immediately, creating the fastest rescue record.
China May Create the Fastest Space Rescue Record, But This Is Not What China Wants
It should be known that the emergency space rescue systems of the United States and Russia have serious problems. Take the United States as an example. On June 5, 2024, Boeing's Starliner spacecraft was conducting its first crewed test flight. According to the plan, it was supposed to stay at the International Space Station for about a week and return on June 14. However, during the flight, the spacecraft experienced multiple problems, including engine failures and helium leaks. Although it successfully docked with the space station, due to safety considerations, NASA and Boeing repeatedly postponed its return time. This is because NASA no longer had a manned spacecraft; either rely on Russia's Soyuz spacecraft or wait for Elon Musk's Dragon spacecraft. After extensive evaluation, NASA finally decided on March 18, 2025, to return using SpaceX's "Dragon" spacecraft.
This caused two astronauts, Barry Wilmore and Suni Williams, to unexpectedly remain in space for 286 days. Suni Williams had actually become so thin that she looked like a cone face, as if photoshopped. This long waiting period exposed the lack of immediate and reliable backup rescue plans in the U.S. commercial crewed spaceflight system when a single spacecraft encountered complex technical failures.
Russia wasn't much better. On December 15, 2022, ground control personnel suddenly discovered that the pressure of the cooling system on the Soyuz MS-22 spacecraft was dropping sharply. Through analysis of the recordings from the spacecraft's external cameras, it turned out that a micrometeoroid (a small piece of natural rock or dust in space) had pierced the external radiator of the Soyuz MS-22 spacecraft's service module, causing the coolant to completely leak into space. The loss of coolant meant that the spacecraft was in a "critical" state. Russian space agency engineers conducted emergency ground simulations and assessments, ultimately reaching a serious but unavoidable conclusion: the spacecraft was no longer safe and could not carry the crew back to Earth.
As a result, the three astronauts who were originally scheduled to return on March 2023, including American astronaut Frank Rubio, suddenly found themselves in a situation where they couldn't return home.
Faced with this sudden situation, the Russian space agency quickly came up with an alternative plan: to convert the next planned spacecraft, the "Soyuz MS-23," into an unmanned mode and launch it earlier, specifically to serve as a "rescue spacecraft" to the space station. Ultimately, the "Soyuz MS-23," originally scheduled to launch in March 2023, was moved forward to late February to perform the rescue mission. However, even with the early launch, there was still a gap of more than two months between the occurrence of the fault and the arrival of the rescue spacecraft. This meant that the three astronauts on the space station had to wait nearly three months after learning that their return vehicle was destroyed before they could get their new, safe transportation back to Earth.
However, China is different. Starting with the Shenzhou 12 manned spacecraft mission, the Shenzhou spacecraft missions during the construction and operation phase of China's space station have shown a significantly different characteristic, that is, having a backup spacecraft ready at any time.
This is a major leap in China's aerospace engineering management capabilities and manufacturing technology. The core lies in overcoming the challenge of "batch production." In the traditional single-unit production model, each Shenzhou spacecraft is custom-made for a specific mission and independently produced. From construction, testing, to launch preparation, the cycle is long, and the cost is high. If a serious problem occurs during the mission, it would take a lot of time to produce a new spacecraft urgently, which may endanger the safety of the astronauts in orbit or interrupt the entire space station plan.
The batch production model, however, involves the production of multiple spacecraft—usually the mission ship and the backup ship—as a batch. This is similar to the concept of "mass production" in industry, but applied to extremely complex and precise manned spacecraft.
Engineers can conduct various environmental tests, reliability tests, and one-time centralized acceptance for this batch of small products, subsystems, or even the entire spacecraft. This model greatly compresses the development and testing cycle of a single spacecraft, reduces the overall cost, and ensures a high degree of consistency in product status.
It is precisely based on the success of batch production that China can equip each manned flight mission with a backup Shenzhou spacecraft that is in a similar completion status. This backup spacecraft is not simply a "spare part," but a fully functional, well-maintained "hot backup" spacecraft. Once the spacecraft in orbit encounters an extreme emergency situation such as irreparable damage or a major system failure, making it unable to return safely, the ground command center can immediately activate the emergency response procedure.
This backup spacecraft can complete the final inspection, refueling, and execute an emergency launch within a week to go to the space station to retrieve the stranded astronauts. Therefore, the backup spacecraft system established since the Shenzhou 12 mission is not only a technical backup solution, but also a powerful astronaut life safety protection system, ensuring that Chinese astronauts always have a reliable life rescue channel during the long-term, continuous, and stable operation of China's space station.
It's true, China will create the fastest space rescue record in the world, being able to bring back our astronauts within the shortest week, but this is not what China wants. For China, the safety of astronauts is the most important thing.
Next, we will thoroughly assess the condition of the Shenzhou 20, learn from the experience, and optimize the passive protection system of the Shenzhou spacecraft. The Shenzhou spacecraft will also adopt an unmanned mode to leave the space station and return to Earth, and our ground personnel will disassemble and analyze the re-entry capsule.
Shenzhou 23 will also be urgently assembled to prevent economic situations in the space station, and the Shenzhou 21 crew lacks a rescue spacecraft.
Original text: https://www.toutiao.com/article/7569632038588875310/
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