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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 fo

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 billions of dollars and unique opportunities because some people have gotten in their minds that RTG power is evil and dangerous. NASA even canceled the ASRG, based on the Stirling engine, which was 5 times more efficient in terms of radioactive material and would have allowed powering probes for the whole solar system. Imagine a Pluto rover !

nacnud 10y ago
Juno is in a highly elliptical orbit, which will take it within 5000km of Jupiter's cloud tops. This photo was taken from much further away than that. In short, check back in about a month. :)
- azernik 10y ago
  Agreed, and to add more detail for comparison - the current distance is around 2 million kilometers, so resolution should jump by a factor of about 500 (per dimension, not number of pixels) at closest range. EDIT: For a comparison to Hubble - at closest approach JunoCam will get 5 kilometers per pixel [1], while Hubble gets in the region of 120 kilometers per pixel [2]. So, giant jump in quality, though the field of view from up close will be limited. [1] http://planetary.org/blogs/emily-lakdawalla/2011/3133.html http://planetary.org/blogs/emily-lakdawalla/2011/3133.html [2] http://www.spacetelescope.org/images/heic0910q/ http://www.spacetelescope.org/images/heic0910q/
  - jessriedel 10y ago
    Current distance is 2.7 million miles, or 4.3 million km, according to the NY Times caption.
dredmorbius 10y ago
The probe is 2.7 million miles from Jupiter, headed further out (its orbit is highly eccentric). That's nearly 11 times the distance from the Earth to the Moon. At closest approach, Juno will be 2,200 miles from Jupiter, less than 1% of the distance between the Earth and Moon. Space exploration is expensive, and a very large part of that expense is mass. Putting a 2.7 million mile scope on a probe that's going to be spending much of its time far closer in to interesting targets costs mass, and fuel, and other sensing apparatus you can't add. So there's that. It's possible that there are higher-resolution capabilities for the probe as well, or that post-processing or higher data rates will improve current images. It's also possible that visual reconnaissance wasn't a high priority for this mission, though I'm not familiar with the sensing platforms included. Given orbital eccentricity, Juno can acquire and store high-quality data, and transmit that at leisure during the outbound parts of its orbit.
- mikeash 10y ago
  Strictly speaking, the probe will be spending most of its time at distances like these. That's the nature of elliptical orbits. But it'll spend enough time up close to get some great pictures. And yes, photos weren't a priority at all. If it were just a matter of returning scientifically useful data, they wouldn't have included this camera at all. But NASA likes pretty pictures too, so they included one.
  - drzaiusapelord 10y ago
    >But NASA likes pretty pictures too, so they included one. Well, everyone does. If it wasn't for this photo we wouldn't be discussing Juno here on HN nor would this mission be in the press right now. It seems crazy to me not to put a camera on deep space missions. The cost is trivial in the grand scheme of things.
    - mikeash 10y ago
      I don't know that the cost is trivial. The camera is cheap, sure, but that's weight and power and bandwidth that could be spent on something else. However, I totally agree that it would be crazy not to include one, and whatever it costs, it's well worth it.
drzaiusapelord 10y ago
>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 missions. Heck, Curiosity was launched just a few years ago and has 11lbs of plutonium powering its RTG. I hardly see a conspiracy here. Also RTGs add weight and cost to projects. If you don't need one, you probably shouldn't be using one - even ignoring their rarity. Missions like Juno get significant weight savings using solar. >I don't know if the cam is the problem or the transmission bandwidth, The quality of the photo has to do with the distance from Jupiter. It has nothing to do with "power." This is a spacecraft, not a gaming PC. Yes more power would mean a higher bitrate, but the bitrate it uses is good enough for the mission.
- cornholio 10y ago
  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.
  - teh_klev 10y ago
    > Sorry, but you have no ideea what I'm talking about. You are probably to young to remember... We don't speak to each other like that here, regardless of how right or wrong the previous poster's knowledge of the subject at hand.
- mikeash 10y ago
  Juno is the first use of solar panels for a probe going that far out. You're right that they want to err on the side of caution using well-known technology to minimize risk. But you're missing the fact that RTGs are that well-known risk-minimized technology. If solar panels saved weight, they would have been used on past missions like Galileo. Better solar panel technology will eventually shift the balance, but we're not there yet. Juno's panels weigh 340kg. Galileo's two RTGs, which produced about the same amount of power at Jupiter, weighed 57kg each.
mikeash 10y ago
Juno's solar panels produce as much power at Jupiter as Galileo's RTGs did. The quality of this picture has nothing to do with solar power. It's a bad picture because Juno is on a highly elliptical orbit for reasons of efficiency and longevity (there's tons of radiation closer in) and this picture was taken when the probe was very far away.

nacnud 10y ago

Juno is in a highly elliptical orbit, which will take it within 5000km of Jupiter's cloud tops. This photo was taken from much further away than that. In short, check back in about a month. :)

azernik 10y ago
Agreed, and to add more detail for comparison - the current distance is around 2 million kilometers, so resolution should jump by a factor of about 500 (per dimension, not number of pixels) at closest range. EDIT: For a comparison to Hubble - at closest approach JunoCam will get 5 kilometers per pixel [1], while Hubble gets in the region of 120 kilometers per pixel [2]. So, giant jump in quality, though the field of view from up close will be limited. [1] http://planetary.org/blogs/emily-lakdawalla/2011/3133.html http://planetary.org/blogs/emily-lakdawalla/2011/3133.html [2] http://www.spacetelescope.org/images/heic0910q/ http://www.spacetelescope.org/images/heic0910q/
- jessriedel 10y ago
  Current distance is 2.7 million miles, or 4.3 million km, according to the NY Times caption.

dredmorbius 10y ago

The probe is 2.7 million miles from Jupiter, headed further out (its orbit is highly eccentric). That's nearly 11 times the distance from the Earth to the Moon. At closest approach, Juno will be 2,200 miles from Jupiter, less than 1% of the distance between the Earth and Moon. Space exploration is expensive, and a very large part of that expense is mass. Putting a 2.7 million mile scope on a probe that's going to be spending much of its time far closer in to interesting targets costs mass, and fuel, and other sensing apparatus you can't add. So there's that. It's possible that there are higher-resolution capabilities for the probe as well, or that post-processing or higher data rates will improve current images. It's also possible that visual reconnaissance wasn't a high priority for this mission, though I'm not familiar with the sensing platforms included. Given orbital eccentricity, Juno can acquire and store high-quality data, and transmit that at leisure during the outbound parts of its orbit.

mikeash 10y ago
Strictly speaking, the probe will be spending most of its time at distances like these. That's the nature of elliptical orbits. But it'll spend enough time up close to get some great pictures. And yes, photos weren't a priority at all. If it were just a matter of returning scientifically useful data, they wouldn't have included this camera at all. But NASA likes pretty pictures too, so they included one.
- drzaiusapelord 10y ago
  >But NASA likes pretty pictures too, so they included one. Well, everyone does. If it wasn't for this photo we wouldn't be discussing Juno here on HN nor would this mission be in the press right now. It seems crazy to me not to put a camera on deep space missions. The cost is trivial in the grand scheme of things.
  - mikeash 10y ago
    I don't know that the cost is trivial. The camera is cheap, sure, but that's weight and power and bandwidth that could be spent on something else. However, I totally agree that it would be crazy not to include one, and whatever it costs, it's well worth it.

drzaiusapelord 10y ago

>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 missions. Heck, Curiosity was launched just a few years ago and has 11lbs of plutonium powering its RTG. I hardly see a conspiracy here. Also RTGs add weight and cost to projects. If you don't need one, you probably shouldn't be using one - even ignoring their rarity. Missions like Juno get significant weight savings using solar. >I don't know if the cam is the problem or the transmission bandwidth, The quality of the photo has to do with the distance from Jupiter. It has nothing to do with "power." This is a spacecraft, not a gaming PC. Yes more power would mean a higher bitrate, but the bitrate it uses is good enough for the mission.

cornholio 10y ago
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.
- teh_klev 10y ago
  > Sorry, but you have no ideea what I'm talking about. You are probably to young to remember... We don't speak to each other like that here, regardless of how right or wrong the previous poster's knowledge of the subject at hand.
mikeash 10y ago
Juno is the first use of solar panels for a probe going that far out. You're right that they want to err on the side of caution using well-known technology to minimize risk. But you're missing the fact that RTGs are that well-known risk-minimized technology. If solar panels saved weight, they would have been used on past missions like Galileo. Better solar panel technology will eventually shift the balance, but we're not there yet. Juno's panels weigh 340kg. Galileo's two RTGs, which produced about the same amount of power at Jupiter, weighed 57kg each.

mikeash 10y ago

Juno's solar panels produce as much power at Jupiter as Galileo's RTGs did. The quality of this picture has nothing to do with solar power. It's a bad picture because Juno is on a highly elliptical orbit for reasons of efficiency and longevity (there's tons of radiation closer in) and this picture was taken when the probe was very far away.