Preface
A month ago, the mainland launched two "moon-orbiting satellites" at the Xichang Satellite Launch Center, which suddenly became abnormal after entering space.
I thought that the satellite would no longer be able to continue its mission, but in a short period of time, it "came back to life" and began to go to the moon 220,000 kilometers away alone!
What the hell is going on?
The launch of the DRO satellite failed
At 8:51 p.m. on March 13 last month, two of the mainland's "moon-orbiting satellites" were successfully launched into space by the upper stage of the Long March-2C launch vehicle/Yuanzheng-1S.
However, the first and second stages of the Long March-2 carrier rocket flew normally, but the "flight of the upper stage was abnormal", so the launch mission failed and did not enter orbit as planned.
So, what's going on with this "upper stage" launch anomaly?
So, first of all, let's understand the mission of the Long March-2 launch vehicle, the main mission of the Long March-2 is to help the mainland's two DRO A/B satellites go into space.
The main role of the "Expedition-1S upper stage" is a "space shuttle car", and its main task is to send the satellite to the predetermined orbit.
Therefore, this time, the two DRO A/B satellites did not successfully enter the scheduled orbit due to the "abnormality in the upper stage", so this mission has been a "launch failure".
Because of the abnormal launch at the "Expedition-1S upper level", the two satellites were equivalent to riding in a car, but suddenly the car broke down.
These two satellites are equivalent to "getting off halfway", and the worst plan is that these two satellites will "wander" directly in space.
When this news came, everyone was silent, because the success rate of the mainland's Long March series rockets was very high.
This launch is the 511th launch mission of the "Long March" series of rockets, and the Long March rockets have achieved "180 consecutive victories", if this mission fails, then the "winning streak" of the Long March rockets is estimated to be ended.
And as of March 13 this year, the Long March-2C has launched a total of 77 times, and only in 2011 did the "Shijian-11-04 satellite" fail once, and the launch success rate can reach 98%, so this failure is rare.
After the report of the launch failure came out, it was believed that this was the first failure of the mainland's satellite launch in 2024, and it was also the end of the Long March rocket launch mission.
You must know that the two satellites of DRO A/B shoulder very important tasks and are also an important step in the continental lunar exploration project, so they have high expectations for the two satellites of DRO A/B.
I thought that the mission had failed, but the "DRO A/B" satellite was "miraculously resurrected" a few days later!
So, why did "DRO A/B" suddenly come back to life?
Current DRO A/B Satellite Status
The news of this "resurrection" was also announced by the 18th Space Defense Squadron of the United States.
The U.S. Space Force's 18th Defense Squadron, a unit dedicated to monitoring spacecraft and near-Earth asteroid activity, appears to be able to record spacecraft orbital flight data in real time.
According to the tracking data of the US Space Force, the two satellites were originally only in an elliptical orbit of 525 kilometers at perigee and 132577 kilometers at apogee, and they are still 220,000 kilometers away from the moon.
But the U.S. Space Force found that the two satellites were still working normally, so they monitored the two satellites.
It wasn't until March 26 that the U.S. Space Force observed new data.
The data shows that the two satellites have been separated from the "Yuanzheng-1S upper stage" launcher and have been ignited at least once.
At present, the position of the two satellites is already in a large elliptical orbit with a perigee of 971 km and an apogee of 225193 km.
In other words, the two satellites climbed to a perigee of 971 kilometers and an apogee of more than 90,000 kilometers on their own after the "abnormal launch of the upper stage".
In this way, the two satellites "DRO A/B" did not abandon their mission, and also climbed high and headed for the predetermined orbit!
As a result, the DRO-A/B satellites have tried to save themselves because they have fuel and thrusters on board, and they have been using fuel to correct their orbits.
Therefore, with this successful orbit change, the DROA/B satellites are one step closer to their orbital targets.
The DROA/B are still in the process of changing orbits, and if they can accelerate at the right time, the apogee will be lifted up to 380,000 kilometers away.
It has successfully entered the "Earth-Moon transfer orbit", and as long as there is enough fuel left for braking, then the two satellites can continue to complete the mission.
After the "launch failure" of these two satellites, the official report is that "relevant disposal work is being carried out", so what may happen after the "failure" may also be within the program design of mainland scientists, so there is still a "remedy" method.
Therefore, "satellite self-rescue" should also be a plan in the design, which is inseparable from the consideration and calculation of scientists in the design.
After all, the process of ascensing a satellite is a very delicate and technically difficult task in itself.
It is necessary to have a precise degree of control over the propellant carried on the satellite, and this time the DROA/B satellite can complete the ascent of orbit through its own propellant.
It also proves that the mainland's current technology in satellite technology and lunar exploration projects is becoming more and more mature, and it also provides valuable experience for the mainland's subsequent satellite launch missions.
These two satellites are called "DRO A/B", and you must know that most satellites will have their own names, such as "Chang'e-1".
So, what does the "DRO" in the names of these two satellites mean?
What does DRO mean?
The full name of DRO in English is Distant retrograde orbit, which means long-distance retrograde orbit around the moon, and after knowing this name, you will know why these two satellites are called "DROA/B".
DRO is a stable archetypal retrograde orbit in the Earth's and Moon's orbits, which means that the direction of this orbit is completely opposite to the direction of the Moon's orbit around the Earth.
The main reason is that this DRO orbit is equivalent to a "lunar high-speed railway", which is a high lunar orbit with a radius of about 61,500 kilometers.
This orbit is very special, and the spacecraft and satellites operating on this "high orbit" do not need to use power plants to adjust the speed of the spacecraft.
Therefore, as long as it enters the DRO orbit, there is no need to correct the parameters of the orbit, and it is not necessary that the operating orbit of the spacecraft must be within the same range as the standard orbit.
This means that as long as it enters the DRO orbit, it can save a lot of fuel for the spacecraft and satellite, and it will require much less spacecraft operation than the previous orbit.
Therefore, as long as these two satellites are officially through this long-distance retrograde orbit around the moon, they only need to change their orbits once again to be successfully sent into the lunar orbit.
Not only that, but the continent was the first country to enter the DRO orbit and the first to send a spacecraft to the moon through the DRO orbit.
The "Chang'e-5" launched by the mainland a few years ago is a mission completed through the DRO orbit, which also proves that the mainland's level of science and technology and innovation in the field of space exploration and space is above that of many countries.
Then, in addition to the two satellites of DROA/B, in fact, in February this year, the mainland also launched a DRO series satellite into orbit.
That is the DRO-L satellite, this satellite was launched into space through the mainland's "Jielong-3 launch vehicle", and this launch vehicle launched on February 3, carried 9 satellites at the same time, and went into space together.
Moreover, it was used in the sea to enter space by launching rockets from ships, and all nine satellites entered the predetermined orbit.
Among them, the main role of DRO-L's satellite is to establish Earth-Moon communication with DROA/B, realize Samsung networking, and establish Earth-Moon connection.
In the future exploration of the moon, it can be realized for the future space missions of the mainland, navigation, communication, formation flight, orbit change and other operations.
Therefore, the importance of the DRO series of satellites is self-evident.
It is believed that DROA/B can successfully enter the predetermined orbit and add strength to the construction of the mainland's lunar exploration program.
So, how far has the mainland's lunar exploration program progressed?
China's lunar exploration program
The mainland's lunar exploration program has never stopped, nor will it abandon the lunar exploration program because of one or more failures.
Since 2004, China has officially launched the lunar exploration project, also known as the "Chang'e Project", which is also the mainland's reverie for the moon and space from ancient times to the present.
On October 24, 2007, Chang'e-1 of the mainland lunar exploration program was successfully launched, and after completing the mission very well, it ended its mission, which also proved the end of the first phase of the mainland lunar exploration program.
Later, "Chang'e-2" and "Chang'e-3" also completed their target tasks very well, and achieved a soft landing and automatic patrol survey on the lunar surface through "Yutu".
Not only has a large amount of lunar data been obtained, which has laid a good foundation for the mainland's subsequent lunar exploration project, and the "Chang'e-3 lander" has overfulfilled the task.
The Chang'e-3 lander, which has only one year of design life, was supposed to stop working in 2016.
But up to now, the probe on the Chang'e-3 lander is still conducting scientific observations, so it has become the longest lunar probe in human history.
I have to admire how meticulous and careful the mainland aerospace scientists are in designing the probe and carrying out the space mission, and the redundancy and life design of the probe are too high, and they are still working for nearly 10 years.
Therefore, the "DRO A/B satellite" can be "resurrected" because China's aerospace scientists are too serious about aerospace engineering, considering a variety of plans and various sudden situations in space.
Therefore, the DRO A/B satellites can return to the predetermined orbit beyond human cognition and continue to complete their mission.
Not only that, with the mainland's Chang'e-6, it will also be launched in the first half of this year.
At this point, the first phase of the mainland's Chang'e project is about to be completed, and the second stage of the "manned lunar landing" will enter in the next few years.
After the completion of the "manned landing on the moon," the third stage of the mainland is to "establish a lunar base" on the moon.
It is believed that in the future, the mainland's manned landing on the moon will also become a normal stage.
epilogue
Therefore, the "resurrection" of the DRO-A/B satellites has really shocked the whole world! It not only demonstrates the strength of the mainland's science and technology, but also marks the mainland's strength in the field of aerospace.
Of course, this is also inseparable from the efforts of the astronauts and scientists on the mainland, and it is precisely because of their efforts that our scientific and technological strength will make breakthroughs again and again and accomplish impossible tasks again and again.
Resources:
DRO-A/B Satellite Launch Abnormality-Xinhuanet
Draw-A/B卫星发射异常
Full analysis of China's Long March series of launch vehicles_Rolling News_Chinese government website
The mainland has successfully launched nine satellites including the DRO-L satellite
The Chang'e-6 probe arrived at the launch site and is scheduled to be launched in the first half of the year
China's Preliminary Plan for Manned Moon Landing Announced Plans to Launch a Lunar Landing by 2030 to Carry Out Scientific Exploration__Chinese Government Network
DRO-A/B Satellite Launch Abnormality-Chinanews.com