Chang'e 3 second lunar day of operations Options

[Paolo]

Yutu alive and well!
http://china.cnr.cn/NewsFeeds/201401/t2014...514628680.shtml

[Explorer1]

Great news! Those 'peaks of eternal light' at the poles are looking more and more enticing as future landing spots; no tense regular waits...

[nprev]

Is there an English option on that site, Paolo? If so, I can't find it.

[kenny]

This is a secondary news source but has been reliable in the past...

Chang's 3 update - January 11

On Saturday, the sun climbed high enough as seen from Yutu to illuminate the vehicle's solar arrays and trigger the automatic wake-up of the rover. Yutu woke up from lunar night sleep mode
and established communications with ground stations on Earth allowing teams to confirm that the 120-Kilogram rover was alive and in good condition. Yutu raised its mast as part of the automatic
wake up sequence and teams began an inspection of the rover and its surroundings before resuming surface operations. Driving was expected to resume later on Saturday.

The Chang'e 3 lander is planned to wake up from its two-week sleep on Sunday in order to resume final payload commissioning and science operations.

[Paolo]

Is there an English option on that site, Paolo?

I don't know. I google translated it

[kenny]

Xinhua news agency says the rover Yutu has started moving again. The lander was wakened up 27 hours after the rover.

Xinhua - rover wakes up

[Phil Stooke]

Looking around at our surroundings a bit as we look forward to the second lunar day... here is a comparison of a descent image and the reprojected circular panorama:



The main craters are probably visible on the horizon.

There have been statements about driving 7 to 10 m at a time, imaging the surroundings and choosing the next drive segment.
This is intermediate between the joystick-style direct driving of the Lunokhods with live (if intermittent) TV images, and the Mars experience of planning a drive of 100 m or so, imaging, and sending data down for the planners to work on the next sol.
Presumably the ground team in China could do several of those short drive segments in an Earth working day, but I'm not sure they could ever get up to distances of 1000 m/day like that (the Lunokhod record was 3000 m in one Earth day).
The stated goal of driving as much as 10 km would require a long extended mission, it seems to me.

Phil

[Phil Stooke]

I spoke to soon about driving. I have now found that the speed will be about 200 meters per hour, and each "step" of about 7 meters will be based on images... yes, but clearly the hazard avoidance and route planning is done rapidly on board and not back on Earth between each imaging session. I should have seen that, but it's difficult working through these machine translations.

Phil

[Explorer1]

So that's just over two days to drive 10 kilometers then (assuming no science stops and taking night shifts on Earth!). In two weeks Yutu could easily break Lunakhod's record....

[elakdawalla]

What's your source on that, Phil?

[Phil Stooke]

Glurk! My original comments came from Spaceflight101, but I have lost my reference to the second source - I'm trying to get back to it but it's very difficult to do that for translated pages. I will post it if I find it.

Phil

[Hungry4info]

So that's just over two days to drive 10 kilometers then (assuming no science stops and taking night shifts on Earth!). In two weeks Yutu could easily break Lunakhod's record....

I wonder how much the energy budget limits how far it can drive in a day.

[djellison]

Those two small arrays, but at Earth distance, rather than Mars distance, are probably putting out several hundred watts - enough to run a vehicle of MER class constantly.

[Phil Stooke]

Here:

http://english.cntv.cn/program/newsupdate/...15/100791.shtml

is a report on the robot arm and APXS operations earlier today. A screen in the operations room shows a perspective view of the landing site.

Here it is deperspectivised (that is a word, right?) to approximate a map view, presumably of the location of the test. I will update the map shortly.




Phil

[Phil Stooke]

Oops, here's another one from:

http://english.peopledaily.com.cn/102774/8513020.html

(4th page of that story) - a bit closer to the big rock.



Phil

[Phil Stooke]

http://news.xinhuanet.com/photo/2014-01/17/c_126023483.htm

First astronomy data from the lander... I don't know anything about it.

Phil

[Cosmic Penguin]

Finally the panorama from the lander's MastCam has been found in print form (although still not quite available in full resolution - that might take a while to be released), although it was released as seven distinct photos so here's the panorama stitched by NSF member OzWill:

Attached thumbnail(s)

 

[Explorer1]

Fantastic! Apparently we shouldn't expect more color pictures from the lander, since the camera had no heater to survive the first lunar night (see Emily's blog post). If there's any gifs of the rover driving over the horizon they'll probably be b/w.
Next LROC imaging opportunity is Wednesday the 22nd; presumably the next chance to update the route map too.

[Paolo]

the panorama appears to contain a number of artifacts. notice in particular the vertical dark strips. I was also wondering what are the two yellowish areas on both sides of the gold-wrapped tank just to the left of the first tracks of Yutu. reflections from the thermal protection? the tank itself appears to be cut toward the top...
BTW, this should really belong to the first day of operation thread

[kenny]

The mission control team has been re-organised in anticipation of a year of operations, they now say.

Chang'e new missions - Xinhua

[4th rock from th...]

Yes, all the color images seem to be raws (if true they are quite good).
There are uncorrected gradients and some color areas at the left / right edges. And gamma/exposure seems to be way off.
The lunar surface is darker than that, but I understand that for media it may look better like this.

[wildespace]

My Photosynth panorma, from the individual images at http://www.chinanews.com/tp/hd2011/2014/01-18/293067.shtml

--> http://photosynth.net/view.aspx?cid=d9db94...30-43ec1a510dbc

And with auto-color correction in Photoshop:
http://photosynth.net/view.aspx?cid=3ee991...f8-a605fcdecf78

[kenny]

I was also wondering what are the two yellowish areas on both sides of the gold-wrapped tank
just to the left of the first tracks of Yutu. reflections from the thermal protection? the tank itself appears to be cut toward the top...

I guess these are reflections off the 2 tanks, one yellow patch off each tank, but displaced to the left (westwards) on account of the sun angle. There were other bright
reflections on the ground underneath Yutu's panels in several of the detailed rover pics.

Yes, I agree the top of the left tank is cut off and the tubing crudely pasted on. To the left of that tank, part of one rock appears twice, so the pan in that area is a bit rough.
But a lovely scene overall, and a nice view of the pyramid rock on the edge of the big crater, which Yutu is now approaching.

[Phil Stooke]

Re: the cut-off tank.

The pan is 3 tiers of images high (and I don't know how many images long), but as the camera tilts to take each tier there will be a mismatch between the foreground (spacecraft components) and the background (lunar surface). When the images are pasted together you have a choice, align the spacecraft components or align the lunar surface components. You can't do both without very ingenious Curiosity MAHLI-self-portrait-style calisthenics. MAHLI could do it because it could be moved, this camera can't because it's fixed.

Phil

[wildespace]

The south-facing part of the lander panorama, with a boxed area indicating the field of view taken by a photo of Yutu we've seen earlier:


(Source for second image: http://news.xinhuanet.com/english/photo/20...33036156_10.htm )

Looks like the lander's panoramic camera had a good zoom. Shame the camera is no longer functional after the cold lunar night, or we could have gotten a more detailed panorama, or individual images, from the lander

[Edit] Andrew Bodrov has created this amazing 360-degree panorama at http://www.360cities.net/image/lunar-panor...change-3-lander
Even the Earth, snapped by Chang'e 3 on a separate occasion, is there. ;-)

[Phil Stooke]

That's not a zoom, I think the full panorama did have that resolution everywhere.

Sun sets on the 25th. I am hoping we will get a summary of the activities during this lunar day soon, and we should also have another LRO image to look forward to.

Phil

[Cosmic Penguin]

Oh well the lander and rover are still alive and working - in fact late on January 22 (UTC) the rover performed direct data exchange to the lander via UHF - the first time two Chinese spacecraft communicate to each other on another planetary body.

Source

[Liss]

Oh well the lander and rover are still alive and working - in fact late on January 22 (UTC) the rover performed direct data exchange to the lander via UHF...

Source

From the distance of 24 meters, is it correct?

[nprev]

UHF is line-of-sight only, so when/if Yutu goes over the horizon with respect to the lander that channel's gone. I forget how close that is (it's too early and I'm too lazy to do the math), but I wonder if that will restrict the radius of operations of the rover.

[SpaceListener]

About the Range of radio UHF

- Handheld radios generally will talk "radio-to-radio", "line-of-sight" up to 2 miles (3.2 kilometers). Once you start putting obstacles in between the radios you will shorten your range. Even the body fluid of the person wearing the radio on their hip will absorb some of the range. Higher wattage radios will have a slight increase in range and a significant increase in clarity of transmission on the outer fringes of your range.

- Mobile radios, such as those mounted in vehicles, will generally talk "radio-to-radio" 8-10 miles depending upon the obstacles and the terrain.

- Base stations will generally talk approx. 8-12 miles. Contrary to popular belief wattage does not determine distance. Antenna height and placement determines distance.

So the Yutu rover won't go so far from the station. So now we already know which interesting places that Yutu's rover can visit, so this is a good point

[Paolo]

So the Yutu rover won't go so far from the station. So now we already know which interesting places that Yutu's rover can visit, so this is a good point

you are neglecting a detail: Yutu also has direct-to-Earth comm capability

[djellison]

UHF is used between MODY/MRO and MER/MSL at Mars, over ranges of hundreds of miles at speeds up to 2 Mbits/sec

The problem would be line of sight over the horizon. But Yutu has DTE, so the issue doesn't actually matter.

[Cosmic Penguin]

Hmm, the rover has problems just before getting into the second lunar night....

China's moon rover monitored with abnormity
English.news.cn 2014-01-25 10:48:05

BEIJING, Jan. 25 (Xinhua) -- China's moon rover "Yutu" (Jade Rabbit) has had an abnormity, and scientists are organizing an overhaul, the State Administration of Science, Technology and Industry for National Defence said on Saturday.

(source)

From what I have read from Chinese sources, it seems that the problem is with the solar arrays failing to tuck back into the rover body for thermal protection during the lunar night. Big oops if that can't be solved in a few (Earth) day's time...

[nprev]

Yeah, the DTE channel was obvious based on the dish. I just wonder how willing the mission operators are to let Yutu get too far away from the lander since if it gets too far away the UHF option is gone.

This is a first time for them, and really for anyone since 1976 on the Moon since DTE links from pretty much anywhere else don't work for control, merely data return. Not sure what's the priority here: exploration or engineering test. Should become evident over time, of course, but way too early to tell.

[Phil Stooke]

The plan always was to drive several kilometers, up to 10, and they would very soon get out of line of sight given the crater rims etc., so DTE would have to be the main communication method.

My concern right now is that they have very little time to fix this issue with the panel. The sun is about to disappear.

Phil

[Thorsten Denk]

According to this list,
the sun HAS disappeared at 08:35 UTC,
little more than one hour after your post...

O-o...

Thorsten

[dilo]

Very scaring situation, indeed.
PS: correct me if I'm wrong, not a single image was released from 2nd day of activities, up to now...

[kenny]

Ken Kremer has done a rather nice version of the Chang'e 3 lander panorama showing Yutu at 3 different positions. It is a little over 360 degrees.

Ken Kremer Chang'e 3 panorama

[Phil Stooke]

There's still a lot we don't know, but this site:

http://www.gov.cn/jrzg/2014-01/25/content_2575558.htm

says Yutu has been driven over 100 m, so that would be some tens of meters beyond where my map shows it. I still have no indication where it is right now but I would hope that at the very least it had examined the large rock and maybe driven north from there a little way.

Phil

[dilo]

Ken Kremer has done a rather nice version of the Chang'e 3 lander panorama showing Yutu at 3 different positions. It is a little over 360 degrees.

And if you look carefully to credits, I am the other guy!

[Explorer1]

If the issue is some stuck motor, there might still be hope to survive the night. Perhaps the temperature changes might loosen whatever component is jammed and the panels can be folded in before too much damage is done (sort of like one of the strategies for Galileo's HGA deployment). That's assuming there's enough juice left to to receive commands and actually follow them...

[general]

http://www.scmp.com/news/china/article/141...ces-abnormality


Very few details about the mishap, but...

...Professor Jiao Weixin , deputy director of the China Society of Space Research's space probe committee, said it was surprising that problems should occur so soon.
"Despite some minor problems, Opportunity, the US Mars rover that also had a design lifespan of three months, is still working after almost 10 years," Jiao said.
"It is quite surprising that Yutu should experience problems at such an early stage."

[Paolo]

A preprint which appeared online a few days ago: Geologic characteristics of the Chang’E-3 exploration region

[DDAVIS]

Here is my version of that initial elevated pan from the lander.

-DD-

http://planetary.s3.amazonaws.com/assets/i...TULNDRPANDD.jpg

[kenny]

And if you look carefully to credits, I am the other guy!

Sorry Dilo! I should have noticed that ..... very nice work. And I see you avoided putting in the same rock twice, which others did!

[Steve G]

This article was on CNN this morning.

http://www.cnn.com/2014/01/27/world/asia/c....html?hpt=hp_t3

[Thorsten Denk]

Anything known about if LRO has taken new images of Cháng'é-3 + Yùtù?

Thorsten

[Phil Stooke]

There was supposed to be an image on Jan. 22, I think, about 3 days before sunset. It's not released yet. There were probably images on several adjacent orbits. This LPSC abstract:

http://www.hou.usra.edu/meetings/lpsc2014/pdf/1859.pdf

has an oblique image from the end of the first lunar day, so we may have had more like that as well as an overhead view.

Only a few days to sunrise for Yutu and Chang'E 3 now - I was just looking at the wide crescent tonight. It's getting bigger!

Phil

[Steve G]

Most of the Surveyors survived the first lunar night, and that was in the 1960's. We'll keep our fingers crossed.

[Explorer1]

This is the second lunar night for both spacecraft though. The main landers should be fine, but Yutu itself...

[SpaceListener]

Today LROC was over the Change'3 landing around 144 km at 2:05 GMT.

http://lroc.sese.asu.edu/whereislro/

[djellison]

Today LROC was over the Change'3 landing around 144 km at 2:05 GMT.

http://lroc.sese.asu.edu/whereislro/

And it would have been dark.

[Thorsten Denk]

Sun is up again in Chang'e land.
Will Yutu wake up once more?...

[elakdawalla]

I've heard of some rumors on Weibo that Yutu survived, but I have also heard that these rumors are hoaxes, so I'm not reporting them in the blog.

[ustrax]

手指交叉...

[PaulH51]

I'll cross my fingers as well 手指交叉

[nprev]

Hell, I'm even crossing my eyes here...

[Yeh]

From a credible source from Weibo: "we should get message from Yutu around Feb 10 at 3pm (Beijing Time; that's 7h UT, or 2am EST), and we will know if it is up for work, or cannot move anymore".

http://www.weibo.com/2032349831/Aw3NFAa6l

[Paolo]

Yutu (and this paper) have made it to the cover of Science China Physics, Mechanics & Astronomy
http://phys.scichina.com:8083/sciGe/fileup...40212181816.jpg

[SpaceListener]

Interesting article about Who framed Jade Rabbit?
Click the following link : From the editorial Space Review.