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Comment by pjtr | Hacker News Reader

These are from 5.4 million km away. According to [1], in a few days (July 14) a Pluto system flyby is planned, at a distance of just 12.5 thousand km (and a speed of 13.78 km/s), and they can take images of Pluto's surface at 70m resolution. Pluto's circumference is 7232 km. So, do I understand this correctly that we can realistically expect to see much higher resolution images soon?

Or is the bandwidth really that limiting? It seems that even at 1kbps it would be possible and worth it to transfer some slightly higher resolution images. A typical color JPEG image at 640x480 is at most around 200kB, so that would take 27 minutes to transfer. For example here[2] is Mars at 640x480 in 38.4 kB. Is that unrealistic?

[1] http://pluto.jhuapl.edu/News-Center/Resources/Press-Kits/NHP...

[2] http://i.imgur.com/0vdGSV1.jpg

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The raw image resolution isn't that bad [1], just that at that distance the planet is still pretty small. The LORRI instrument actually has an 8 inch mirror which is the best ever ever carried to the outer solar system.

As for receiving the high res images, the full data dump will take months after the flyby to be sent back. I read though as a fail safe in case new horizons were to damaged during the flyby that they will be transferring a high res image early into the flyby.

New Horizons is also unable to face Pluto and talk to earth at the same time, which limits what we can get back at this stage.

[1] http://pluto.jhuapl.edu/soc/Pluto-Encounter/data/pluto/level...

Emily Lakdawalla has written an excellent guide explaining what can be expected to be seen over the next several days:

http://www.planetary.org/blogs/emily-lakdawalla/2015/0624055...

Indeed excellent, thanks! TLDR: Yes! "Pluto at 3.8 kilometers per pixel (~630 pixels across disk)."

That's transmitted shortly after closest approach, but that won't be the highest resolution image taken. It's just the highest resolution where pluto still fits into the frame. The highest resolution images will just be of portions of Pluto. One will come in on the 15th, but I believe the rest won't be transmitted until September due to the slow uplink speed.

If I'm not mistaken they'll receive low-res versions of the pictures then download the full-sized ones later

From the Planetary Society website

"On September 14, New Horizons will begin downlinking a "browse" version of the entire Pluto data set, in which all images will be lossily compressed. It will take about 10 weeks to get that data set to the ground. There will be compression artifacts, but we'll see the entire data set. Then, around November 16, New Horizons will begin to downlink the entire science data set losslessly compressed. It will take a year to complete that process."

The P.I. Dr Alan Stern said at the Denver science museum a couple weeks ago they are a using as many of the backup instruments as they can to double the capacity. Many of the crucial instruments like the antenna have duplicates for the nine year journey.

If we are shortly going to have that kind of resolution of Pluto, I'm a little curious that we haven't mapped nearer objects down to almost Google maps level detail. I would think that with Cold-War spy satellite technology, even, orbiting the moon, we could have every inch mapped in short order.

Maybe we did already, and it wasn't that interesting? I remember the Google Earth desktop client having a Moon mode at one time, but that may have been a tie-in when Curiosity landed on Mars.

> Maybe we did already, and it wasn't that interesting?

https://en.wikipedia.org/wiki/Clementine_(spacecraft)#Missio...

> The lunar observations made included imaging at various wavelengths in the visible as well as in ultraviolet and infrared, laser ranging altimetry, gravimetry, and charged particle measurements. These observations were for the purposes of obtaining multi-spectral imaging of the entire lunar surface

This mission's result is what you see in "Visible" mode on Google Moon https://www.google.com/moon/

We've mapped the Moon and Mars to 0.5m resolution or so.

Wonder whether they're using compressed sensing [1] to capture and transmit the images.

[1] https://en.wikipedia.org/wiki/Compressed_sensing

edit: ans no (I think).

The bandwidth is that bad. It will take months to retrieve the data from closest approach.

Does anyone know what kind of capacity the internal storage on NH has? I hope that it's not going to run into issues buffering across space and filling up it's SD card like the remote game cameras that I've put up, that get punked by overactive squirrels.

Interesting question!

"For data storage, New Horizons carries two low-power solid-state recorders (one backup) that can hold up to 8 gigabytes (64 gigabits) each." (From [1] linked above.)

In 2005 that was about what they could fit on the craft with weight, power, space limits. Now it just a single memory stick.

The 2003 Mars rover Spirit was among the first to use flash. Even though the OS was 25 years old battle tested version of UNIX called VxWorks, the flash driver was new. It had a bug that incorrectly marked the free inode list on flash disk. So about six weeks into the mission the disk appeared to be full and caused a safe mode reboot every few hours. The engineers successfully uploaded a patch and one of rovers is still operational.

And we're still not flying memory sticks (but we are flying more memory than ever before). Fun fact: New Horizons has no file system on its recorder, but current missions at APL now do.

http://flightsoftware.jhuapl.edu/files/2012/FSW12_Mick.pdf

Thanks, sorry, did not read TFLs in any depth... Pre-coffee

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