Author Topic: Danuri/Korean Pathfinder Lunar Orbiter  (Read 19012 times)

Offline Blackstar

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Danuri/Korean Pathfinder Lunar Orbiter
« on: 10/18/2021 04:12 pm »
https://www.leonarddavid.com/south-koreas-first-moon-mission/

This is a decent-sized spacecraft. Scheduled for August 2022 launch.

"Explains Mark Robinson, ShadowCam’s principal investigator at Arizona State University, the instrument is based on the successful Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) and will be over 100 times more sensitive (altitude dependent) than the current NAC."



« Last Edit: 01/09/2024 12:07 am by zubenelgenubi »

Offline edzieba

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #1 on: 10/18/2021 04:36 pm »

Offline Blackstar

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #2 on: 10/19/2021 12:41 am »
ASU ShadowCam site: http://shadowcam.sese.asu.edu/about

And by comparison, the LROC camera that it is derived from:

http://lroc.sese.asu.edu/about/specs

They both have the same focal length, although LROC has two narrow angle cameras compared to a single one on ShadowCam. However, I assume that the same focal length will provide the same ground resolved distance (resolution) on the lunar surface.

Offline ccdengr

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #3 on: 10/19/2021 01:16 am »
However, I assume that the same focal length will provide the same ground resolved distance (resolution) on the lunar surface.
The sensor pitch is larger (12 microns as compared to 7 on LROC) so the resolution is lower by that ratio.

Offline Phil Stooke

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #4 on: 10/19/2021 07:03 am »
LRO takes those images of shaded areas at the very limit of what it can do, and the very weak signal is boosted by binning pixels (I forget the bin size right now) - so resolution in shaded areas is much poorer than the nominal 50 cm/pixel.  Shadowcam should give much better signal at significantly higher resolution.

Offline edzieba

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #5 on: 10/19/2021 10:29 am »
Found a presentation on ShadowCam that highlights the major difference with the LROC's WAC: instead of the 1 x 5064 pixel line array, ShadowCam uses a 128 x 2916 pixel array, with TDI integrating between lines (as the array scans due to spacecraft movement, the lines are stepped in sequence to 'hover' a virtual line in place without smearing).

Offline redliox

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #6 on: 01/05/2022 06:50 pm »
ASU ShadowCam site: http://shadowcam.sese.asu.edu/about

And by comparison, the LROC camera that it is derived from:

http://lroc.sese.asu.edu/about/specs

They both have the same focal length, although LROC has two narrow angle cameras compared to a single one on ShadowCam. However, I assume that the same focal length will provide the same ground resolved distance (resolution) on the lunar surface.

It is excellent to see a new camera preparing to see the Moon.  I keep forgetting how old LRO is, so anything with current technology will only improve what that craft has done.  It will definitely be a great feather for Korea to put in it's spacefaring cap.
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Offline Tywin

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Offline Tywin

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The Turtle continues at a steady pace ...

Offline Phil Stooke

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #9 on: 08/05/2022 03:26 am »
In the headline story:  "its orbit will have reached an apogee near the Earth/Moon Lagrange Point 1 (L1)."

But Jonathan McDowell tweets:

@planet4589
Danuri will head out to Sun-Earth Lagrange 1, and then fall back in towards the Moon, to enter lunar orbit.  Similar approach to the CAPSTONE mission.
4:27 PM · Aug 4, 2022·

So, Earth-Moon or Sun-Earth?
« Last Edit: 08/05/2022 03:41 am by Phil Stooke »

Online gongora

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #10 on: 08/05/2022 03:29 am »
Sun-Earth

Offline Phil Stooke

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #11 on: 08/05/2022 03:39 am »
Yes - I was just going to respond to my own post.  Here:

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

on the KARI website is an illustration of the path... it clearly shows the trajectory nearing Sun-Earth L1, but it is incorrectly labelled EM1. 

The same source has an illustration of the approach to lunar orbit after the excursion to Sun-Earth L1.  As it approaches the Moon it does a little jiggle around the Earth-Moon L2 point.
« Last Edit: 08/05/2022 03:45 am by Phil Stooke »



Offline sdsds

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Re: Danuri/Korean Pathfinder Lunar Orbiter
« Reply #14 on: 08/06/2022 11:28 pm »
[snip]

Goldstone DSS 24 and DSS 26 in active communication with KPLO.

https://eyes.nasa.gov/dsn/dsn.html
« Last Edit: 08/06/2022 11:30 pm by sdsds »
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