Author Topic: Chang'e-4 lunar operations (Read 278094 times)

Satori · « **Reply #260 on:** 01/11/2019 03:13 pm »

Craters surrounding Chang'e-4 pose challenge to lunar rover.

Satori · « **Reply #261 on:** 01/11/2019 03:14 pm »

China declares Chang'e-4 mission complete success.

Dalhousie · « **Reply #262 on:** 01/12/2019 12:45 am »

Video of Yutu rolling across the surface, showing two different steering modes

Lsquirrel · « **Reply #263 on:** 01/12/2019 02:39 am »

Quote from: SciNews on 01/11/2019 08:59 am

Chang’e-4 landing (Onboard Camera View)

official landing video：
http://www.sastind.gov.cn/video/2018/C4jlsp.mp4

Steven Pietrobon · « **Reply #264 on:** 01/12/2019 03:20 am »

Yutu journal!

http://www.xinhuanet.com/english/2019-01/11/c_137736993_7.htm

Steven Pietrobon · « **Reply #265 on:** 01/12/2019 03:23 am »

I took some screen grabs of the landing sequence. I added a red dot in the first photo showing the approximate landing location.

SciNews · « **Reply #266 on:** 01/12/2019 10:13 am »

Zhang Hongbo, chief designer of Chang'e-4's ground application system, about the movie and the landing. The video was slowed down to match, as best as possible, the timeframe.

ugordan · « **Reply #267 on:** 01/12/2019 04:02 pm »

Blackstar · « **Reply #268 on:** 01/12/2019 04:44 pm »

Produced by Mark Robinson, PI of the LROC instrument.

http://www.leonarddavid.com/nasa-moon-orbiter-pinpoints-chinas-farside-landing-locale/

Liss · « **Reply #269 on:** 01/13/2019 11:55 am »

Current Chinese lunar plans for Phase 4:

探月四期任务规划了嫦娥四号、嫦娥七号、嫦娥六号、嫦娥八号任务！
The fourth phase of the lunar exploration mission has planned the tasks of the No. 4, No. 7, No. 6, and No. 8!
研制系列化、长寿命、可持续使用的探测器功能模块，在月球南极附近构建月球科研站基本型，具备全月面到达长时间工作高智能协同能力，开展月球环境和资源探测及利用。
Develop a serialized, long-life, and sustainable detector function module to build a basic type of lunar research station near the moon's south pole. It has a full-time, long-term, high-intelligence synergy capability, and conducts lunar environment and resource detection and utilization.

2018年前后完成嫦娥四号月球背面着陆巡视探测
2018 year approx. completed Chang’e 4 Lunar back side lander and rover research
2023年前后实施嫦娥七号极区环境与资源勘查
2023 year approx. completed Chang’e 7 Polar area environment and resource exploration
2024年前后实施嫦娥六号月球极区采样返回
2024 year approx. completed Chang’e 6 Moon polar area sample return
2027年前后实施嫦娥八号月球极区资源开发利用验证
2027 year approx. completed Chang’e 8 Lunar polar area resource development and utilization verification

http://passport.acfun.cn/a/ac4857461
https://twitter.com/LiuyiYiliu/status/1084396577404284928

eeergo · « **Reply #270 on:** 01/13/2019 05:44 pm »

https://twitter.com/AJ_FI/status/1084465932687286272

SciNews · « **Reply #271 on:** 01/14/2019 07:45 am »

Chang'e-4 mission press conference, 14 January 2019

cjx007 · « **Reply #272 on:** 01/14/2019 08:39 am »

Quote from: eeergo on 01/11/2019 12:44 pm

Quote from: ugordan on 01/11/2019 12:40 pm
Here's the previous landing for reference, altitude is marked in the lower right:

I think you converted me, I see now Thanks for the comparison!

Sun Zezhou (Chef Designer for Chang'e 4) said hover was 100m in the conference today. Not sure what's going on.

http://www.scio.gov.cn/xwfbh/xwbfbh/wqfbh/39595/39653/index.htm

eeergo · « **Reply #273 on:** 01/14/2019 10:36 am »

Short tidbit about immediate future roving plans after dawn at the end of the month:

https://twitter.com/AJ_FI/status/1084721946162532352

Prettz · « **Reply #274 on:** 01/14/2019 04:35 pm »

Quote from: Satori on 01/11/2019 03:14 pm

China declares Chang'e-4 mission complete success.

Already? I thought an objective of this one was to last a lot longer than Chang'e 3.

Blackstar · « **Reply #275 on:** 01/14/2019 04:42 pm »

Quote from: Prettz on 01/14/2019 04:35 pm

Quote from: Satori on 01/11/2019 03:14 pm
China declares Chang'e-4 mission complete success.
Already? I thought an objective of this one was to last a lot longer than Chang'e 3.

I suspect this means "so far."

The program almost certainly has their own set of mission success criteria. I don't know what they are, but in the case of NASA there is usually a "primary mission phase" with a set of objectives that have to be achieved. This is more than just "land and turn on" and is usually based upon the quality of returned data--so it's not just that you've turned an instrument on, but that it is getting the data that you specified as required to achieve the science objectives.

So I'm guessing that the CE4 program managers have their own list of success criteria and they probably require operating on the surface for at least a certain amount of time and gathering a certain amount of data.

Phil Stooke · « **Reply #276 on:** 01/14/2019 04:49 pm »

Also there is always a 'minimum success' definition. I think for MER it was something like land, full panorama, rove 10 or 20 m, make 2 APXS measurements (I don't have details of this, but something like this). Then you go to the expected primary mission success level of 90 sols, 100 m, some number of APXS results and so on. For Chang'e 4 we are presumably at the minimum success level, but they hope for many months of roving and up to 10 km distance travelled.

luhai167 · « **Reply #277 on:** 01/14/2019 05:16 pm »

Quote from: Blackstar on 01/14/2019 04:42 pm

Quote from: Prettz on 01/14/2019 04:35 pm
Quote from: Satori on 01/11/2019 03:14 pm
China declares Chang'e-4 mission complete success.
Already? I thought an objective of this one was to last a lot longer than Chang'e 3.

I suspect this means "so far."

The program almost certainly has their own set of mission success criteria. I don't know what they are, but in the case of NASA there is usually a "primary mission phase" with a set of objectives that have to be achieved. This is more than just "land and turn on" and is usually based upon the quality of returned data--so it's not just that you've turned an instrument on, but that it is getting the data that you specified as required to achieve the science objectives.

So I'm guessing that the CE4 program managers have their own list of success criteria and they probably require operating on the surface for at least a certain amount of time and gathering a certain amount of data.

It means the engineering goal of the programs is a complete success, and the project can be turned to its science portion with Chinese Academy of Science in the driver seat. In this case, I suspect it means it landed in where CAS wanted to land, all instruments deployed and tested to their customer’s satisfaction to allow it to be handed over. It also opens gate block that hinged on the success of this mission.

For example, CE3 was declared a completely success fairly early as well, which meant CE4 can go for a more ambitious landing site. Given the announcement of CE7 and CE8 shortly after the CE4 declared success, I guess their mission funding depended on it.

wahaha · « **Reply #278 on:** 01/14/2019 11:33 pm »

Worth reading.
https://www.dailymail.co.uk/sciencetech/article-6589155/China-wants-3D-print-lunar-base.html

Blackstar · « **Reply #279 on:** 01/15/2019 12:38 am »

Quote from: wahaha on 01/14/2019 11:33 pm

Worth reading.
https://www.dailymail.co.uk/sciencetech/article-6589155/China-wants-3D-print-lunar-base.html

I think the filters you need to apply to Daily Mail articles are so thick that even when they do have actual news, it's almost impossible to trust it.

One of the lines I snorted at was right in the title: "and reveals it intends to return again THIS YEAR"

Yeah, they "revealed" plans for CE5 several years ago. It's not like this is sudden.