China working to save classifed lunar mission from launch failure
Orbital data now suggests that Chinese engineers are attempting to save a classifed lunar mission from the failure of its launch rocket to put the two satellites in their proper high orbit.
The small DRO-A and B spacecraft launched from Xichang spaceport on a Long March 2C rocket March 13. Hours later, the first acknowledgement of the mission came from Chinese state media Xinhua, which announced that the spacecraft had not been inserted accurately into their designated orbit by the rocket’s Yuanzheng-1S upper stage. “The upper stage encountered an abnormality during flight, causing the satellites to fail to accurately enter the preset orbit,” Xinhua stated. “Relevant disposal work is currently underway,” it added, citing Xichang launch center.
Data from the U.S. Space Force’s 18th Space Defense Squadron (SDS) initially showed objects associated with the launch in low Earth orbit (LEO). However, subsequent Two Line Element (TLE) data sets, a mathematical representation of a satellite’s mean orbit, from 18 SDS show an object from the launch (international designator 2024-048A) in a 525 x 132,577-kilometer, highly-elliptical, high Earth orbit. This has since been raised, with the spacecraft tracked in a 971 x 225,193-km orbit on March 26.
This indicates that at least one satellite, and perhaps both—if still attached to one another—separated from the upper stage, and that the object’s orbit has been raised.
It is very possible that further engine burns could put these satellites into lunar orbit, which would then save the mission and turn the March 13 launch failure into a success.
Why China is keeping this particular lunar mission so secret is another question, that still remains unanswered.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Orbital data now suggests that Chinese engineers are attempting to save a classifed lunar mission from the failure of its launch rocket to put the two satellites in their proper high orbit.
The small DRO-A and B spacecraft launched from Xichang spaceport on a Long March 2C rocket March 13. Hours later, the first acknowledgement of the mission came from Chinese state media Xinhua, which announced that the spacecraft had not been inserted accurately into their designated orbit by the rocket’s Yuanzheng-1S upper stage. “The upper stage encountered an abnormality during flight, causing the satellites to fail to accurately enter the preset orbit,” Xinhua stated. “Relevant disposal work is currently underway,” it added, citing Xichang launch center.
Data from the U.S. Space Force’s 18th Space Defense Squadron (SDS) initially showed objects associated with the launch in low Earth orbit (LEO). However, subsequent Two Line Element (TLE) data sets, a mathematical representation of a satellite’s mean orbit, from 18 SDS show an object from the launch (international designator 2024-048A) in a 525 x 132,577-kilometer, highly-elliptical, high Earth orbit. This has since been raised, with the spacecraft tracked in a 971 x 225,193-km orbit on March 26.
This indicates that at least one satellite, and perhaps both—if still attached to one another—separated from the upper stage, and that the object’s orbit has been raised.
It is very possible that further engine burns could put these satellites into lunar orbit, which would then save the mission and turn the March 13 launch failure into a success.
Why China is keeping this particular lunar mission so secret is another question, that still remains unanswered.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Is lunar orbit difficult to achieve? I have read that because of the irregular shape ( or is the density? ) of the moon the orbit has to be just right.
Steve,
These are two different effects.
Getting to lunar orbit from the Earth is difficult in two ways. First, it takes a lot of propellant to get there. Just getting to low Earth orbit takes a large rocket, and getting to lunar orbit takes some more, so that there is a tiny amount of payload delivered compared to the amount of propellant used in order to get there. This tiny ratio is considered as a difficulty.
Second, there are different types of trajectories that can be used in order to get to lunar orbit from low Earth orbit. A man named Hohmann created a type of transit orbit, named after him, that was intended to use the least amount of propellant to go between planets or between the Earth and the Moon, but better trajectories for the lunar destination were realized later. Apollo used a transit orbit that was an elliptical orbit with an apogee (highest point) somewhere past the Moon, but as the Moon caught up to the spacecraft, they intersected each other, and Apollo could easily go into orbit with an engine burn. Since the Moon is also in its own elliptical orbit, sometimes closer to the Earth and then farther from the Earth, it takes less propellant to get there when the intersection happens when the Moon is closer. There are other routes that use even less propellant but take longer duration.
“Why Spacecraft Are Using These Crazy Routes To The Moon”
https://www.youtube.com/watch?v=WVrWcbyOmxY (14 minutes)
Less propellant means more payload or a less expensive launch vehicle. In the video, Scott Manley talks about Lagrange points and the force of gravity. However, it is not just gravity but the angular momentum of the satellite or probe, the Moon, and the Earth. Orbital mechanics is a complex topic that is often counterintuitive, so if this all does not make sense to you, I understand. I took an orbital mechanics class and it barely makes sense to me, too. Manley also talks about how many kilometers per second velocity must change, and this is how orbital mechanics (mechanicsists? mechanicalists?) tend to calculate how to change from one orbit to another, and the propellant needed to make the change is then calculated based upon the change in velocity and the mass of the probe whose orbit is being changed.
The other effect you wondered about has to do with mass concentrations within the Moon. It is not uniformly dense, thus as low-flying satellites pass by a mass concentration, they tend to be attracted more than when they are farther away, such as on the other side of the Moon, and this attraction changes the orbit. The mountains and seas of the Earth have a similar but less pronounced effect.*
“Why Do Lunar Satellites Eventually Crash Into The Moon?”
https://www.youtube.com/watch?v=EadClM4Y45A (9 minutes)
___________________
* There is a “bulge” of the Earth, where the diameter at the equator is about six miles more than the diameter from pole to pole (the shape of the Earth is a small bit like an M&M candy), which acts like an Earth-sized three-mile-high mountain and allows for sun synchronous orbits — another interesting phenomenon of orbital mechanics.