On November 9, 1967, the Saturn V moon landing rocket was launched for the first time at the Kennedy Space Center. The moon landing rocket and the moon were in the same frame before the launch of
On November 16, 2022, the Kennedy Space Center, the space launch system (SLS) moon landing rocket was launched for the first time.
Time flies, and the only two moon rockets that humans put into use are actually 55 years apart. But they have a common goal: conquer the moon. Once upon a time, it was the moon landing plan named after the sun god " Apollo " in the myth of ancient Greek ; and now, it is the return to the moon plan named after the lunar god " Artemis ". In legend, these two gods are twins, and nothing cooler than naming the two major plans with them.
. The past and present life of the space launch system
"Apollo" moon landing plan was the peak of the human space race in the last century. The United States achieved great success: not only 12 astronauts successfully landed on the surface of the moon, but also gained great international influence, completely defeating the Soviet Union's dream of landing on the moon.
success or failure. After the Soviet Union finally decided to give up the moon landing, the "Apollo" moon landing soon seemed extremely cost-effective: on the one hand, after the 17th mission, it was difficult to make new discoveries, and the moon has been proven to be a barren planet; on the other hand, the project cost too high. In 1967, NASA even used up 4.5% of the federal budget, 10 times the proportion today. For example, the Saturn V moon landing rocket alone costs $2 billion in a single launch, which is too expensive.
previous launches of the Saturn V rocket (Photo source: NASA)
Therefore, the Saturn V rocket ended after only 6 years of use. Its related projects, funds and human resources were invested in the later space shuttle program, becoming NASA's largest project from the 1980s to 2010s. But then it also encountered a similar problem. The single launch cost was too high (US$1.5 billion), which was like the effect of "killing chickens with a stinger" in many projects, especially after the rise of commercial aerospace, the space shuttle project seemed rather embarrassing: the same capacity as commercial rockets, the price was 10 times, and it also had to risk their lives, which was not worth it.
Against this background, the space shuttle project finally ended in 2011. However, in order to maintain the launch capability of the space shuttle in deep space and large payloads, while supporting future plans to return to the moon, NASA urgently needs an heavy launch vehicle, , which can carry the beam. This is the background of the emergence of SLS. The design of
SLS is more like the "rocket version" of the space shuttle. Since it does not have to transport huge "cabins" into space like a space shuttle, it can transport heavier payloads and achieve a capacity close to Saturn V.
From the outside, you can find that SLS and the space shuttle have obvious intergenerational inheritance (Photo source: NASA)
SLS's four core engines are RS-25D, the main engine of the space shuttle. It has long verified excellent reliability and reusability. Almost no major problem has occurred. It is the ceiling of human liquid hydrogen liquid oxygen rocket engine technology. The core level, that is, the "big orange can" without any coating, is mainly loaded with liquid hydrogen and liquid oxygen propellants and core engines. In addition, its core thrust comes from two solid boosters, which are also upgraded versions of the shuttle booster. It weighs 725 tons, but its thrust is as high as 1,600 tons. A booster can push a Long Five rocket (the takeoff weight is about 870 tons). It is indeed a violent monster.
According to the combination of core engine capabilities (RS-25D and RS-25E), upper-level capabilities (three models) and solid booster capabilities (three models), SLS will have three main models, Block-1, Block-1B and Block-2. In this launch, it is a Block-1 type with a low-Earth orbit capacity of about 100 tons. The final version of Block-2 has an equivalent capacity of more than 130 tons, and the lunar transfer orbit capacity reaches more than 45 tons, reaching even more than the former Saturn V moon landing rocket.
Generally speaking, SLS will become the "big killer" to carry out a timely development of NASA: it is not easy to take action, and taking action is an aerospace project that can be used on big news.
2. The main content of the first launch
Before the troops moved, the food and grass came first. The most needed support to land on the moon is not only the SLS lunar rocket, but also the Orion deep space exploration manned spacecraft, the deep space portal orbiting lunar space station, the lunar surface lander and ascender are launched one after another. As of now, each project has cost more than US$50 billion, which can be described as a "gold-swallowing beast". The first launch of
, namely the "Artemis 1" mission, is the first full system inspection of these large-scale projects. According to the plan, the mission lasts for 4-6 weeks, and the Orion spacecraft and a series of small satellite are released near the moon. After completing the established mission, Orion returned to the moon and splashed down the ocean and was recycled. The entire system process of the
"Artemis 1" mission (Photo source: NASA)
In the specific implementation stage, this mission includes 17 core nodes, basically testing all core indicators of rockets and spacecraft. Among them, when leaving Earth, the upgraded LC39 rocket launch platform needs to be tested for the full system capabilities of the upgraded LC39 rocket launch platform. This was once the starting point of the "Apollo" moon landing plan, but after 50 years, it has been a completely different rocket. Whether this platform can "get stronger and stronger" determines the success or failure of the mission.
In the phase of leaving the earth, it needs to go through a series of operations such as the separation of the dual booster/ fairing / escape tower separation, core stage separation, maneuvering orbit, leaving the orbit around the earth and cutting into the moon's transfer orbit, etc. This is basically the fixed business process of the Saturn V rocket back then, and needs to be accurately reproduced. During this process, the Orion spacecraft will separate from the rocket's upper stage, which will then arrange 10 small satellites.
On the way to the moon, Orion needs to maneuver for a long time to ensure that it can accurately meet the moon. Unlike other lunar exploration missions, the main body of the spacecraft will not orbit the moon in this mission, but will use the moon to enter a special orbit called "DRO". This is an extremely stable orbital family in Earth and Moon system. The propellant required to maintain operation here consumes very little, so it has become the best choice for Earth and Moon space detection and even manned space stations in the future. It is a hot spot in lunar research in recent years. my country has taken DRO orbit research as a key breakthrough in the Chang'e-5 mission and the new batch of "pilot projects" of the Chinese Academy of Sciences , which shows its significance.
The first mission of "Artemis" is naturally to accumulate valuable flight experience for future missions through actual flight of DRO orbit. It is expected that Orion will fly here for no less than 6 days. After fully obtaining the data, it will leave independently, and finally return to the atmosphere of the earth and splash down to the sea.
It should be noted that the speed at which the spacecraft returned from the near the moon arrives at the earth will be close to the second cosmic speed (11.2km/s), far exceeding the first cosmic speed (7.9km/s) returned from the orbit of the earth. The heat gap with the atmospheric friction is nearly 3 times, and the requirements for the spacecraft's heat protection and structural strength are greatly improved. This is also the "most difficult" moment for the Orion spacecraft.
50 years later, Arturo Campos got the opportunity to "fly" to the moon (photo source: NASA)
SLS is a manned moon rocket. The core test of nature is the manned capacity of the Orion manned spacecraft . It is unrealistic to take risks with real astronauts on the first mission, and replaced by a real-person scale model. The launch carries a dummy called Captain Campos, named after Arturo Campos, an engineer who once solved a major problem with the Apollo 13 mission. Correspondingly, there is also a dummy flying with him. One of them will be strictly protected, while the other will be exposed as much as possible to test the impact of space radiation on the human body. The two models are equipped with various complex sensors to test various indicators during flight.In addition, there are NASA's "Snoopy" dolls symbolizing the manned space flight and ESA's "Shaun Sheep" dolls symbolizing the manned space flight of the European Space Agency.
The powerful transportation capacity cannot be wasted. SLS has left many scientific research institutions with space to complete various lunar exploration missions. As mentioned earlier, it will carry and release ten small satellites from the United States, Italy and Japan, a new record unprecedented in the history of lunar exploration. These small satellites have different functions, including space weather, lunar remote sensing, earth observation and new technology verification, and can be said to be a huge lunar exploration fleet.
3. The future of SLS
After the first task, "Artemis" will continue to use the Block-1 model to perform two tasks. In the second mission, a manned flight exploration around the moon will be directly carried out, which is expected to be carried out in 2024. In 2025, the third mission will be carried out, carrying four astronauts to the moon, two of whom will land on the moon, truly achieving the exploration goal of "returning to the moon". The final selected lunar surface lander plan, due to the participation of commercial companies such as SpaceX, is completely different from the aerospace development environment led by the "national team", and it also makes people look forward to it.
"Moon Portal" Lunar Space Station Art Concept Map (Photo Source: NASA)
And in subsequent missions, the moon's "Space Portal" space station will be gradually established. It will operate stably in the earth-moon space. On the one hand, it will maintain stable communication with Earth passenger flights to achieve long-term resident personnel, and on the other hand, it will land on the surface of the moon as needed and maintain a stable lunar base . In the longer term, this will also become the best "springboard" to provide a stable platform for Mars exploration, asteroid exploration and other deep space exploration missions. There is no doubt that this means a huge international cooperation framework with more than twenty countries participating.
However, almost nothing unexpected happened, SLS has become a "Rocket Assassin". Currently, its single launch price is expected to be no less than US$2 billion at a time, reaching or even exceeding Saturn V's level. Taking the core engine RS25-D as an example, taking the contract of Rocket's supply of engines by the SLS rocket, the cost of a single engine is as high as about US$100 million, but SLS has to throw away four units at one launch. You know, the expensive space shuttle back then was used repeatedly.
Although it was for major projects at the beginning, the price was too outrageous. Moreover, due to the fact that R&D significantly exceeded expectations, the first launch of SLS was delayed by 18 consecutive times, with a delay of more than 5 years. Correspondingly, the overall R&D expenses have further soared, and the mass production speed is not as expected. The subsequent launch schedule has become tense, resulting in it being basically only planned to serve the "Artemis" plan in the future.
NASA's new generation of Jupiter probe "Europa Clippers" (Photo source: NASA)
Take the previous "Europa Clippers" order as an example. As NASA's new generation flagship Jupiter detection mission, the project budget is extremely high, and the launch cost of SLS is not that sensitive, but the schedule of SLS is constantly delayed, making it difficult for this mission to get the rocket launch opportunity as scheduled, and the orders are eventually lost. The order for the "Europa Clippers" was eventually taken away by SpaceX's Falcon Heavy Rockets. Although its deep air capacity is not as good as the SLS, it is still the world's strongest rocket before the SLS is in service, far exceeding all other active rockets. The key is that the quotation is only one-tenth of that of SLS. Even if the launch capability makes the mission unable to reach Jupiter, NASA cannot resist this super high cost-effectiveness.
starship has undergone propellant filling and ignition tests, waiting for its first flight (Photo source: SpaceX)
At the same time, starship , which has the same low-Earth orbit capacity as SLS, is also ready to wait for the test. SpaceX has invested huge resources in this project, blowing up nearly 20 prototypes in succession, and finally waiting for the first flight. If the Starship can really achieve full-ship reuse and a single launch cost of tens of millions of dollars, then SLS will be even more embarrassing.
Both have the same abilities and a 20-fold difference in price. Who will be more attractive?
