Danuri: Korea's first lunar orbiter Options

[Phil Stooke]

https://www.kari.re.kr/eng/sub03_07_01.do


The link is to the Korean Space Agency's page on Danuri, the nation's first lunar orbiter. It will launch from the US in early August and orbit the Moon for a year. Of particular note is he inclusion of Shadowcam, a US payload modified from the LRO NAC instrument to image in polar shadows. I think I have seen it is 200 times more sensitive that NAC. We can hope for a lot of interesting images of polar areas. Work on a followup lander is in progress but may be slow.

Phil

[mcaplinger]

I think I have seen it is 200 times more sensitive that NAC.

Something like that; larger pixels (12 micron instead of 7), 32 TDI stages, and a higher QE sensor. It was a big pain to test compared to NAC because we had to use strong ND filters to image any normal scene. More info at http://shadowcam.sese.asu.edu/

[Phil Stooke]

Thanks, Mike.

Thinking about its operation... an area near a PSR but not in it will often be shadowed but sometimes illuminated. When it is illuminated NAC can see it perfectly well, but it will have very pronounced shadows which might complicate mission planning (e.g. a rover traverse into the PSR). There might be some occasions where an area like that could be imaged while in shadow, with the more diffuse reflected light softening the shadows enough to be helpful.

I look forward to seeing the images.

Phil

[mcaplinger]

I look forward to seeing the images.

As do we! Keep in mind that while the launch is just a week away, it takes KPLO quite a while to get to the Moon; mapping won't start until sometime in December, I think. See https://directory.eoportal.org/web/eoportal...missions/k/kplo

[mcaplinger]

BTW, in case this has occurred to anyone -- Shadowcam is not sensitive enough to see by Earthlight, but it's too sensitive to image anything illuminated by the Sun without saturating. So it can really only image shadowed regions slightly illuminated by surrounding lit topography. We tried to make it as insensitive to stray light as we could, but mixes of shadow and sunlight may cause problems -- we'll just have to see.

[Phil Stooke]

https://mobile.twitter.com/CNSpaceflight/st...226075424141313

Danuri images Earth and the Moon.

Phil

[Shan]

BTW, in case this has occurred to anyone -- Shadowcam is not sensitive enough to see by Earthlight, but it's too sensitive to image anything illuminated by the Sun without saturating. So it can really only image shadowed regions slightly illuminated by surrounding lit topography. We tried to make it as insensitive to stray light as we could, but mixes of shadow and sunlight may cause problems -- we'll just have to see.

I am waiting to see images from shadow cam as it gives us more insight into areas like these from NAC near the Shackleton (This is near the landing area of Artemis near the connecting ridge). Max temperature in Summer is around 120K so most probably it might be ice!

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[Phil Stooke]

Round about now Danuri is at its most distant from Earth, 1.55 million km, out near Sun-Earth L1. It will now begin to fall in towards Earth and encounter the Moon in December.

Phil

[Phil Stooke]

A transit (passing over Korea) on 24 September. These are frames from a video on the mission website.

Phil

[john_s]

Sweet! Do you have a link to the original source?

John

[Phil Stooke]

I thought the link I put in the first post in this thread was to that page but I see now that it is not.

Here is the Danuri website's multimedia page:

https://www.kari.re.kr/kplo/multimedia

And this is that specific item:

https://www.kari.re.kr/kplo/danuri/multi/mu...&searchWrd=

Phil

[Phil Stooke]

Danuri is approaching the Moon:



It will enter lunar orbit on the 17th.

Phil

[Phil Stooke]

Safely in orbit and getting close to its 100 km science orbit. Meanwhile, see this excellent FISO talk by Ben Bussey (now at Intuitive Machines, previously NASA).

https://fiso.spiritastro.net/telecon/Bussey_12-21-22/

Phil

[Hungry4info]

Absolutely incredible images from KPLO posted to twitter.

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[Explorer1]

Wow! Like the old LROC Earthrise from 2014, just b/w!