The Dark Moon

[GaryN]

Possibly the Toshiba T4KB3, BSI sensor.

It is actually a IMX214 Sony sensor, very similar specs. Capable of 60 fps with decent lighting but we see only a few still images from it. I was hoping to find EXIF data for the images but think it has been removed.

[GaryN]

All going well, Artemis 1 will soon be heading for lunar orbit. A good opportunity I thought to show us some video during the trip and from lunar orbit with cameras far in advance of those used during the Apollo missions. Can't wait to see the results.

The eyes' of NASA's Orion spacecraft will provide navigation, beautiful views of Earth and the moon
Deep Space Systems, a Redwire company in Colorado, worked with Orion manufacturer Lockheed Martin to add cameras to the spacecraft that will provide high-definition, 4K video.

https://news.yahoo.com/eyes-nasas-orion ... 30815.html
.

[GaryN]

NASA seems to have covered all the bases with choosing the OV5640 based cameras for the Artemis mission. No IR cut off filter so when the visible wavelengths are of very low value we will see IR images.
https://www.technexion.com/wp-content/u ... 0-s84.pdf
If SpaceX are ever allowed to orbit the Moon I hope they uses a GoPro with the IR blocking filter still in place, we'd get a much more honest feel for the true illumination levels.

So how will he images compare to those from the Apollo missions? Will we be able to see the Milky Way or the stars, Mars or Mercury? Lots of time during the trip to experiment but will they even tell us what they are up to in the backroom? It will all be very well choreographed I'm sure.

Korea recently launched the Pathfinder Lunar Orbiter mission which has the US developed ShadowCam aboard.

The ShadowCam instrument was designed based on previous imagers like those found on the Lunar Reconnaissance Orbiter, but it is several hundred times more light-sensitive to allow for capturing details within the permanently shadowed regions.

NASA’s ShadowCam Launches Aboard Korea Pathfinder Lunar Orbiter
https://blogs.nasa.gov/artemis/2022/08/ ... r-orbiter/

The LRO NAC camera used no filters and was sensitive to the near IR down to 750 nm.

[Holger Isenberg]

OV5640 based cameras
[...]
ShadowCam

Could you find some docs indicating the use without IR cutoff filter?

The product description about that model is confusing:
* Vizionlink-OV5640-S84-IR: IR Cut Filter
* Vizionlink-OV5640-S84: Without IR Filter

The camera with -IR in the product name won't capture IR while the one without IR is IR sensitive. That will lead to ordering the wrong camera

ShadowCam is an interesting name! My guess is that it is just a tuned CMOS/CCD sensor, maybe cooled down to be able to add a high external gain. I don't think it is added by a photo multiplier like used for most star trackers in the past, but I may be wrong.

Usually when talking about IR-cutoff filters for CCD/CMOS sensor it means that UV is also blocked below 400nm. But there may be special IR-only cutoff filters.

[GaryN]

Could you find some docs indicating the use without IR cutoff filter?

No. The spectral response of the cameras is not even mentioned in the Artemis 1 mission articles. How many people will even notice? The IR capabilities of the Apollo films and vidicons was not common knowledge either.

Usually when talking about IR-cutoff filters for CCD/CMOS sensor it means that UV is also blocked below 400nm. But there may be special IR-only cutoff filters.

The QE graph for the sensor shows next to nothing below 375 nm so UV blocking not really needed.

[Holger Isenberg]

The QE graph for the sensor shows next to nothing below 375 nm so UV blocking not really needed.

Yes, in this example not much will come in below that. For some of the Mars cameras the UV range was higher. Here an example where I could quickly find a graph, though not that extreme there:

page 62 on https://www.researchgate.net/publicatio ... ion_Report

Also for the UV topic pages 96/97 are interesting as for some unknown reason the Mars camera doesn't really capture the UV-induced fluorescence of rocks in visible light. That's not explained so far as the fluorescence is happening in the visual green light and should be visible by the camera.

[Holger Isenberg]

The spectral response of the cameras is not even mentioned in the Artemis 1 mission articles. How many people will even notice? The IR capabilities of the Apollo films and vidicons was not common knowledge either.

Found something:

All 22 Cameras on Artemis 1 Explained (plus the 150+ pad cameras)
https://www.youtube.com/watch?v=-xv_4fBDC3w

He talks about the cameras onboard: Some GoPro Hero 4 inside and 4 outside on the end of each solar panel. Those should be able to provide nice views. Then a lot of Pixelink PL-D750 series. According to https://pixelink.com/products/industria ... resolution those come all without built-in IR filter and without lenses and I can't see any product listing for an IR filter. That means, the chance is high for not having an IR filter on the Artemis 1 mission on those. The GoPro Hero 4 are modified without the stock lenses and with a new metal case, which also adds a change to have the IR filter removed.

With the IR filter removed, I would expect blurry pictures of Earth during launch as with getting light of up to 900nm mixed together with visual light around 500nm, focusing should be difficult.

[GaryN]

All 22 Cameras on Artemis 1 Explained (plus the 150+ pad cameras)

Thanks Holger. If that bucket of bolts ever gets off the ground then they will be able to put on quite the video show, but of course they will only show us what they want us to see, easy to switch cameras or not show some feeds, and communications bandwidth will of course impose some restrictions. Some video will be recorded and we will see it later, which of course gives time for image processing or manipulation. I am not expecting to see anything that might raise awkward questions, only the eye candy that NASA has had decades to perfect.
Eyes in space, and eyes not subject to non-disclosure limitations, is the only way to get a real feel for conditions out there, though if we are to believe the Apollo astronauts then we already know just how dark it is out there.

Also for the UV topic pages 96/97 are interesting as for some unknown reason the Mars camera doesn't really capture the UV-induced fluorescence of rocks in visible light. That's not explained so far as the fluorescence is happening in the visual green light and should be visible by the camera.

Perhaps the Martian rock is not what they think it is?
That's a very comprehensive article, but given all the science, math and calibration details is there any way to use the data from the camera to determine the reflected lux values of the rock being examined?
I was looking at this article about the spectrum of the Martian sky:
Chromaticity of the Martian sky as observed by the Mars Exploration Rover Pancam instruments
https://www.researchgate.net/publicatio ... nstruments
Again their are no actual measured lux values of the Martian sky, and they use a theoretical brightness based on the solar constant model.
The last time NASA talked about lux values was for the model of the lunar surface brightness under full Earthshine, and came up with 18 lux. Plenty good enough to perform most surface operations by.
Clearly NASA does not want to divulge the actual measured values as they would not fit the solar constant model, which makes perfect sense if there is no visible sunlight! They are scared of light meters, and they are also scared of neutral density filters because if they used one on a COTS camera in deep space it would see nothing!! Prove me wrong NASA.

[Holger Isenberg]

Perhaps the Martian rock is not what they think it is?
[...]
Again their are no actual measured lux values of the Martian sky, and they use a theoretical brightness based on the solar constant model.

Those rocks in the PDF are on Earth, test images taken on Earth with the Mars MAHLI/WATSON camera on the robotic arm. That camera is specialized for close up rock images and strange that they didn't investigated more why the green fluorescence is barely visible. The spectral sensitivity of the camera sensor looks pretty standard like any other digital camera. Maybe they added special lenses with less green transmission as that wasn't measured for the sensitivity graph. There is anyway something special with their lenses as on Earth they all look perfectly clear at the front, but on Mars taken from the other camera, they look like having a purple-reflecting mirror. Could be a dust layer.

The SkyCam on the Perseverance Rover was specially designed to capture the precise solar illumination, but you cannot find much about it. Most likely it got dust covered immediately and was pretty useless afterwards as I don't see any cleaning mechanism and the only dust preventing is from top with a sun shade which won't do much against fine iron oxide dust.

[GaryN]

See DART’s final images before it smashed into an asteroid
https://www.planetary.org/articles/nasa ... roid-crash

Who says stars are not visible in space?
DART’s Small Satellite Companion Tests Camera Prior to Dimorphos Impact
https://www.nasa.gov/feature/dart-s-sma ... hos-impact

LICIACube: the Light Italian Cubesat for Imaging of Asteroids in support to DART(pdf)
https://www.hou.usra.edu/meetings/lpsc2 ... /1873.pdf

[Aardwolf]

Who says stars are not visible in space?
DART’s Small Satellite Companion Tests Camera Prior to Dimorphos Impact
https://www.nasa.gov/feature/dart-s-sma ... hos-impact

LICIACube: the Light Italian Cubesat for Imaging of Asteroids in support to DART(pdf)
https://www.hou.usra.edu/meetings/lpsc2 ... /1873.pdf

I thought LUKE was imaged in the infrared. If so, it may not be able to possible to see those stars if you were along for the ride. LEIA is centered on visible light hence the image of Earth with no visible stars in the background.

[GaryN]

NASA was surprised by the easy visibility of DART's impact from Earth.

Which suggests to me that there was an ionising radiation component. The Bayer filtered camera of LUCIACube would have shown us a bright flash if there was visible light but I see no images from it yet. The panchromatic camera filter was centered at 650 nm, but was wideband going from near UV to near IR.
The images from Earth would require a really bright visible light flash to have been seen so readily, so again I say it was a UV and up flash and Earths atmosphere did the down conversion.
The rocky looking surface may well have been high in quartz so an impact of that nature could have created a high voltage that charged the surface and caused the finer particles to have been mutually repulsed from the surface producing the expanding cloud seen in the Earth based footage.
The ATLAS images may have been using the Hα filter, haven't seen anything about it yet though.

Webb, Hubble Capture Detailed Views of DART Impact
https://www.nasa.gov/feature/goddard/20 ... art-impact

So far I have not seen UV/EUV/Xray observations of the event but for my model to hold up then there would need to have been such emissions.

Aardwolf

I thought LUKE was imaged in the infrared.

LUKE was the Bayer filtered unit, LEIA the IR centered at 650nm, again for the Hα I'd think.

[BuckeyeFrank]

https://www.nasa.gov/sites/default/file ... h_moon.png

What do you all think the angle of the sun was in this image ?

the NASA Lucy mission picture of the day.
https://www.nasa.gov/multimedia/imagegallery/iotd.html

[GaryN]

What do you all think the angle of the sun was in this image ?

The Earth and moon both show a full disk so the Sun would be behind the camera. minimising stray light. Not sure if these imaging devices should be called cameras any more though, they are scientifically far beyond what we might recognise as a camera. That there are no stars visible in that image is interesting though. The camera also goes into the near IR, so would anything be visible by eye at all?

Checking in on the Cameras of NASA’s Asteroids-Bound Lucy Spacecraft
https://www.nasa.gov/feature/goddard/20 ... spacecraft

The camera used here is another puzzler.

NASA’s Juno Gets Highest-Resolution Close-Up of Jupiter’s Moon Europa
https://www.nasa.gov/feature/jpl/nasa-s ... oon-europa

INSTRUMENT_NAME STELLAR REFERENCE UNIT
"The Juno Stellar Reference Unit (SRU) is a low-light, broadband visible
(450-1100 nm) imager with no filters."

"Visible" at 1100 nm? Again, all the data could be in the near IR.

https://pds.nasa.gov/ds-view/pds/viewIn ... OST_ID=JNO

All these images using military spec 'cameras' still do not let us know if our eyes would see anything at all out there. Maybe once the dust has settled I'll join Twitter and see if there is a way to get Elon Musk to tell us what he knows, or maybe to finally get an Amateur Space Telescope in orbit? I suspect his ties to the military would limit what he can say or do on such matters.

[Holger Isenberg]

The GoPro Hero 4 pictures from the Orion solar cell wingtips of Artemis 1 are nice: https://twitter.com/areoinfo/status/1592935816808235009
copied from https://www.youtube.com/watch?v=3J0gqm4MGuQ