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NASA’s Juno Spacecraft Sends First In-orbit View

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Re: NASA’s Juno Spacecraft Sends First In-orbit View

#41

Post by sophacles »

kchoudhu wrote: post #26

I understand the importance of this mission, but after the Curiosity skycrane, the Pluto flyby and the Rosetta orbiter, I'm really jonesing for something cool . What else is in the pipeline?

This brings to mind a moment in the movie Apollo 13, where one of the supporting characters says something to the effect of: "Leave it to NASA to make a moon landing boring".

I think it says a lot of great things about NASA that people consider putting a satellite in orbit around Jupiter to be routine. Further great things from the fact that they really want NASA to stop being "boring" and invent some crazy new thing and push the boundaries of what humans think is realistically possible again - after all its been like a whole year since they blew our minds last time.

All for the low price of ~.03 militaries. (Not including the fact that NASA does some stuff for the military...)

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#42

Post by raverbashing »

mixedmath wrote: post #8

> On later orbits, Juno will continue photographing the poles, but where else the camera will focus will be open to a popular vote by the public. NASA has been pretty active in public outreach. The article indicates that Juno takes something like 4 photos an hour. I wonder whether it will be 1 photo for the public to 3 photos for science, or totally different?

JunoCam is not there for science, but rather for public outreach.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#43

Post by pwthornton »

KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

High resolution photos from Juno will be coming in a few weeks.

This one is fairly low res and grainy.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#44

Post by KnightOfWords »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

Hardly fictional, it's a pretty accurate representation of what Jupiter actually looks like. The main reason for using this technique is because our turbulent atmosphere blurs any image. Taking a video allows only a small percentage of the clearest frames to be combined. A spacecraft doesn't have this problem. The technique is called lucky imaging: https://en.wikipedia.org/wiki/Lucky_imaging

Stacking improves signal-to-noise ratio but does not introduce details that aren't present. A stacked image can be more accurate than a single frame as camera artifacts are reduced.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#45

Post by pwthornton »

jessriedel wrote: post #38
jonknee wrote: post #32

Earlier quoted context omitted.

> It's a wide-field of view and only a few megapixels, so basically a cell-phone camera. It's not similar to a cell phone camera at all. Cell phone cameras are usually much higher resolution (current iPhone is 8 megapixels vs the 2 for Juno), but with a much smaller sensor (iPhone cam has a 1.5µm pixel size vs 7.4µm for Juno).

Um, so the best cell phone camera on the market is within a factor of 2 in linear resolution? I think that qualifies as "basically".

It's the opposite of cellphone camera. It has low megapixels and a large sensor size. This will allow a lot of light onto the sensor and it won't suffer from the noisiness that high megapixels on a smaller sensor suffer from.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#46

Post by ceejayoz »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

Stacking allows errors caused by our atmosphere to be cancelled out. It's an attempt to get it closer to what a spacecraft with no atmosphere to contend with would see.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#47

Post by ceejayoz »

jsingleton wrote: post #14

This is cool. Jupiter is easy to spot with the naked eye, as it's the second brightest object in the night sky after Venus (obviously, excluding the moon when lit). You can even see some of its moons with some basic optics. To think there is a probe there now is a pretty powerful image to inspire children. Something we couldn't do with the recent Pluto visit, as awesome as that was.

A six-inch scope in your backyard gets you this: https://www.flickr.com/photos/ceejayoz/26513799722/in/album-...

My daughter's massively into space, and having a mid-size telescope (Celestron NexStar 6SE) has been truly wonderful. There's something really different about seeing it for yourself even if the picture isn't as good as one from a probe.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#48

Post by ceejayoz »

drzaiusapelord wrote: post #33
peter303 wrote: post #28

Earlier quoted context omitted.

SpaceX might launch a Mars lander during the 2018 low energy window. Though I am guessing more likely the 2020 window following that. NASA is fully cooperating with SpaceX by doing things like providing detailed data of previous Mars landings. NASA is SpaceX largest customer and financier. Many ex-NASA people workmat SpaceX. These data are public. But it helps to have good communication channels.

>SpaceX might launch a Mars lander during the 2018 low energy window. Is this budgeted? Is it on a launch docket? Is there a rocket ready for it? Is the lander completed? 2018 is right around the corner and frankly I'm getting sick of "Spacex might" comments. There's a big difference between "might" and "do." When you see a mission on the NASA roster, its ready to go and unless there's some serious technical issue, i…

Elon Musk time means "2018" is almost certainly going to be 2020 or 2022 (even with NASA's promise of technical support). That said, "landing on barges" is potentially a massive step towards reusable, cheap launch vehicles, and it's one their competitors mocked them for even attempting.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#49

Post by cornholio »

drzaiusapelord wrote: post #34
cornholio wrote: post #7

I understand JunoCam is a public outreach tool. But if it provides much worse resolution than Hubble from inside Jupiter's orbit, it's basically useless even for that. I don't know if the cam is the problem or the transmission bandwidth, one thing is clear, when serios science starts there will be much less bandwidth available to send sharp and cool photos. That's what you get from a solar powered probe. We waste bil…

>gotten in their minds that RTG power is evil and dangerous RTG usage is curbed due to NASA's low supply of plutonium-238. Until more is made it makes sense to design for solar powered systems. Also these are risky missions with high pricetags and erring on the side of caution using well known technologies isn't some big conspiracy. Its to avoid high-profile fails. We can try new and risky stuff in lower profile miss…

Sorry, but you have no ideea what I'm talking about. You are probably to young to remember but going with RTG was immensely controversial when Cassini launched, which had an 135 kbps link. Juno, on the other hand has less than 1kbps, because it needs to carry a large solar array instead of an antenna and has much less power for the uplink - data rate is proportional to the square of transmitter power. Bad publicity is the reason we went with solar on Juno and why NASA canceled ASRG.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#50

Post by dperfect »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

Of course it's a photo. All photography involves varying degrees of processing and subjectivity with respect to the information that is presented or discarded. Stacking may be somewhat less intuitive than a single frame, but conceptually it's no different from a long exposure - it's just selecting the moments of best seeing (minimal distortion from the atmosphere) to include in that long exposure. 400 frames of video at 60 fps is roughly analogous to a 6.7 second exposure in terms of signal vs noise.

Your typical single-frame exposure involves a great number of processing operations and filtering that may be unknown to most people, but still define the "look" of the end product (which is nowhere close to a 1:1 representation of the light entering the lens).

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