Space rescue, "China only needs 8.5 days at the earliest"

Rockets and spacecraft "rolling standby", Singapore media: If Shenzhou 13 encounters an emergency, China can launch a space rescue in 8.5 days

Space emergency rescue capabilities, which have appeared many times in Hollywood science fiction films, have become a reality in the era of the Chinese space station. Singapore's "Lianhe Zaobao" said on the 18th that while China successfully launched the Shenzhou 13 manned spacecraft, the Shenzhou 14 spacecraft has entered an emergency launch state. "If Shenzhou 13 encounters an emergency, Shenzhou 14 can rush to space in 8.5 days as soon as possible to carry out rescue."

According to the Global Times reporter, in the previous Shenzhou 12 and the current Shenzhou 13 manned mission, both the Long 2F carrier rocket and the Shenzhou manned spacecraft have adopted a "rolling standby" strategy. In the event of a situation that requires emergency rescue, both the Arrow and the Ship have the ability to launch quickly.

Emergency rescue is an indispensable capability for manned space exploration in countries around the world. The space station needs to operate in orbit for a longer time, is larger in size than other spacecraft, has more complex functions and systems, and has more maneuvers in orbit and more outer space missions. Under the superposition of multiple factors, the space station faces more potential dangers than other spacecraft. Astronauts stay on the space station for a long time, heavy work, narrow environment, in this special environment, the space station dangerous equipment, materials and accidental operation, may bring threats to the safety of astronauts' lives, so emergency rescue capabilities are necessary for the development of manned space industry. For example, the International Space Station has been docked for a long time with two Soyuz spacecraft to meet the needs of the emergency evacuation of 6 astronauts.

According to experts from the First Academy of Aerospace Science and Technology Group, during the on-orbit construction and operation of the China Space Station, if there is a serious danger or failure of the space station or spacecraft, the ground will quickly launch a rescue spacecraft to bring the astronauts back. Therefore, from the launch of the Shenzhou XIII Changer F Yao 13 rocket began to implement emergency rescue duty, the launch can be carried out as soon as 10 days. According to reports, the Chang'er F rocket now adopts the "rolling backup" launch mode of "launching 1 round and backing up 1 round". This is not a small challenge for the Long Two F rocket, which was not high in the previous launch density, but the developers overcame many difficulties to ensure that before the launch of the Long Two F Remote 12 rocket, the Remote 13 rocket has completed the basic stage, fairing (half cover) and escape tower assembly test, and sealed in the plant, entered the emergency duty state, and has emergency launch capabilities.

According to the specific needs of the space station's emergency rescue mission, the Chang'er F rocket has the ability to launch an emergency within 10 days, and can quickly launch the spacecraft to safely bring the astronauts back. As the Yao-13 rocket transitioned to the normal launch process, the Yao-14 rocket also "took over" as an emergency rescue duty rocket. Therefore, while preparing for the launch of the Yao-13 rocket, the development team must also simultaneously carry out preparations for the emergency rescue status of the Yao-14 rocket.

Chang Wuquan, the overall chief designer of the Changer F rocket, said, "In this mission, under the premise of ensuring reliability, we explored and implemented the parallelism and optimization of the two rocket launch site processes, which is expected to shorten the launch preparation time by about 20%. In addition, we have made technical reserves for the new test and development process. ”

Of course, the most gratifying situation is that everything is going well on the space station, and the rocket on duty has been quietly waiting in the technical position until it moves on to the normal launch process of the next mission.

The Chang'er F Yao-13 rocket, which has been "standing in place" since the launch of Shenzhou XII, has been erected for more than 5 months at the time of launch of Shenzhou XIII. Will such a long-term "standing guard" have a negative impact on the rocket? Chang Wuquan said that after a lot of analysis and testing, the model team believes that the rocket can fully withstand these changes and will not be affected. In addition, for safety reasons, some of the batteries and pyrotechnic devices on the rocket are temporarily not installed and stored in special warehouses. After receiving the emergency rescue mission, it can be quickly installed in place without affecting the rocket launch.

According to experts from the Fifth Academy of aerospace science and technology group, in order to ensure that the sky and the ground have the ability to protect the lives of astronauts and pick up astronauts under emergency conditions, the Shenzhou spacecraft team has created an emergency rescue mission model that combines heaven and earth, that is, to bring two spaceships into the field, with a ship as a backup of the launch ship, as a "life rescue boat" for astronauts in the event of an emergency. It also employs a "rolling standby" strategy, where the latter manned spacecraft is already on standby at the launch site when the previous manned spacecraft is launched, and has an 8.5-day emergency launch capability to achieve space rescue capabilities.

In addition to the emergency rescue support provided for astronauts after launch, when the rocket is launched, the Changer F rocket also adds a fault detection and escape rescue system, with an escape vehicle on the top of the rocket, a full arrow reliability index of 0.97, a safety index of 0.997, which is the carrier rocket with the highest reliability index in China. If the rocket encounters a sudden accident during launch, the escape system will immediately activate and fly away from the faulty rocket with the return capsule like a turnip. The return capsule then separates from the escape vehicle and automatically opens the parachute and slowly descends to the ground. According to Liu Feng, deputy chief engineer of the second F rocket of the first president of the Aerospace Science and Technology Group, the escape aircraft could only escape in a fixed direction before, and there were certain safety risks. "If the escape vehicle can only escape to the east, but at that time, a wind blowing westward from the ground may cause the return capsule to be blown back to the vicinity of the faulty rocket after opening the umbrella, threatening the safety of astronauts."

Therefore, on the basis of the existing control escape engine, the developers added the engine ignition function, so that the escape aircraft can escape in the direction of the wind perpendicular to the ground, which is safer and more flexible. Chang Wuquan revealed, "For example, the ground is blowing a south wind, and now you can choose the east escape perpendicular to the south wind in advance." ”

After improving the rocket's escape system, the safety assessment of the Long Two F reached 0.99996. Chang Wuquan explained that the string of numbers after the decimal point represents that it has an international advanced level, "As far as the current state of technology is concerned, the Average Launch of the Chang'er F rocket is 100,000 times before it is possible to have 4 escape failures." In terms of the safety of astronauts, it is even higher than the level of 'foolproof'."

Source: World Wide Web