Author Topic: LIVE: Chinese CE-5-T1 (Chang'e 5 precursor) - CZ-3C/G2, Xichang - Oct. 23, 2014  (Read 236806 times)

Offline Blackstar

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Thanks. I miss-posted this to the wrong thread. Should be in the CE4 thread. But your interpretation is the same as mine: CE4 uses solar, and a small RTG that provides some additional power, but is not the primary power source.

Offline eeergo

-DaviD-

Offline plutogno

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some scientific results from the lunar orbiting phase of the CE-5T1 mission:

A degree-100 lunar gravity model from the Chang’e 5T1 mission
https://doi.org/10.1051/0004-6361/201936802

Quote
Context. Chinese lunar missions have grown in number over the last ten years, with an increasing focus on radio science investigations. In previous work, we estimated two lunar gravity field models, CEGM01 and CEGM02. The recently lunar mission, Chang’e 5T1, which had an orbital inclination between 18 and 68 degrees, and collected orbital tracking data continually for two years, made an improved gravity field model possible.

Aims. Our aim was to estimate a new lunar gravity field model up to degree and order 100, CEGM03, and a new tidal Love number based on the Chang’e 5T1 tracking data combined with the historical tracking data used in the solution of CEGM02. The new model makes use of tracking data with this particular inclination, which has not been used in previous gravity field modeling.

Methods. The solution for this new model was based on our in-house software, LUGREAS. The gravity spectrum power, post-fit residuals after precision orbit determination (POD), lunar surface gravity anomalies, correlations between parameters, admittance and coherence with topography model, and accuracy of POD were analyzed to validate the new CEGM03 model.

Results. We analyzed the tracking data of the Chang’e 5T1 mission and estimated the CEGM03 lunar gravity field model. We found that the two-way Doppler measurement accuracy reached 0.2 mm s−1 with 10 s integration time. The error spectrum shows that the formal error for CEGM03 was at least reduced by about 2 times below the harmonic degree of 20, when compared to the CEGM02 model. The admittance and correlation of gravity and topography was also improved when compared to the correlations for the CEGM02 model. The lunar potential Love number k2 was estimated to be 0.02430±0.0001 (ten times the formal error).

Conclusions. From the model analysis and comparison of the various models, we identified improvements in the CEGM03 model after introducing Chang’e 5T1 tracking data. Moreover, this study illustrates how the low and middle inclination orbits could contribute better accuracy for a low degree of lunar gravity field.

Online Galactic Penguin SST

As it turns out. it's the 3rd stage of the LM-3C that launched it that is about to crash on the far side of the Moon early next month, not a Falcon 9 2nd stage.

https://www.projectpluto.com/temp/correct.htm
Astronomy & spaceflight geek penguin. In a relationship w/ Space Shuttle Discovery. Current Priority: Chasing the Chinese Spaceflight Wonder Egg & A Certain Chinese Mars Rover

Online spacexplorer

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I'm a little late to the party  ;) because search function could not find this thread.... so I add a hint for search engines:
the object going to impact Moon on March 4th is named WE0913A , was previously thought to be a SpaceX stage used to launch DSCOVR mission, then it has been identified as the stage used to launch Chang'e5 T1.

Here you can find a very complete explanation:

https://www.projectpluto.com/temp/correct.htm

Due to initial mis-identification, the "tracking number" on NASA sites is still associated to DSCOVR mission, which have "-78" as identifier;   this object is indeed identified by "-78000" number.


Calculated trajectory  (starting from 2021-OCT-01):

w.r.t Earth:
http://win98.altervista.org/space/exploration/3d/space-explorer-tracker.html?orbiter=-78000&orbitername=WE0913A&center=@399&start=2021-OCT-01&stop=2022-MAR-04%2012:33&step=10h&3dzoom=800000&radius=6341

w.r.t Moon:
http://win98.altervista.org/space/exploration/3d/space-explorer-tracker.html?orbiter=-78000&orbitername=WE0913A&center=@301&start=2021-OCT-01&stop=2022-MAR-04%2012:33&step=10h&3dzoom=800000&radius=1737

DSCOVR (mis-identification) was launched 2015/02/11 23:03:02 UTC

Chang'e5 T1 was launched 2014/10/23 18:00 UTC

WE0913A ephemeris are available starting 2021/10/01

Foreseen impact site:
latitude +5.18, east longitude 233.55
« Last Edit: 03/03/2022 11:54 am by spacexplorer »

Online spacexplorer

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Offline cpushack

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China maintains that this was in no way their rocket stage, FWIW

Offline Hungry4info3

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China maintains that this was in no way their rocket stage, FWIW
That's not quite correct. As much as certain elements of western society would like to create a major fuss, it's more likely there was a translation error involved here.

https://twitter.com/SegerYu/status/1495811277180260352

TL;DR: The AP asked the Chinese MOF about the Chang'e 5 T-1 upper stage. The Chinese MOF is not exactly the right department for these kinds of questions, but it seems like the response given was for the Chang'e 5 upper stage, which indeed won't be hitting the moon.

Offline Star One

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Quote
The case of the mysterious moon crash is now conclusively closed, a new study reports.


Quote
The mystery involved the identity of the impactor, which astronomers designated WE0913A. Initial observations suggested it might be the upper stage of the SpaceX Falcon 9 rocket that launched the Earth-observing DSCOVR satellite in February 2015. But, after further work, astronomers soon settled on a different candidate: The third and uppermost stage of the Long March 3C rocket that lofted China's uncrewed Chang'e 5-T1 mission around the moon in October 2014.


Quote
The new study also sheds further light on the distinctive crater that resulted from the March 2022 moon crash.


Quote
The most plausible explanation for this behavior, team members said, is a dumbbell-like object — one with considerable mass at each end.

https://www.space.com/moon-crash-march-2022-china-rocket-body

Related paper:

https://iopscience.iop.org/article/10.3847/PSJ/acffb8
« Last Edit: 11/23/2023 04:28 pm by Star One »

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