Aachen
8 days ago
These come from Juno, a mission sent in 2011 and orbiting Jupiter since 2016. Must say it wasn't really on my radar anymore, but looking at the timeline on Wikipedia, it's still going around and getting close ("perijove") every month and a week or so, at an ever-increasing longitude https://en.wikipedia.org/wiki/Juno_(spacecraft)#Timeline The planned end of the mission is in about a year. The camera was "included in the payload to facilitate education and public outreach [but] later re-purposed to study the dynamics of Jupiter's clouds"
foobarbecue
8 days ago
Yeah, they had to fight so hard to get that camera on there! It was not included in the initial designs since it wasn't necessary for the science objectives.
Aachen
8 days ago
Makes me wonder what it costs to send a "simple" camera along. Factors that make it probably not so simple: even 200 grams of camera (and extra solar panels to supply +10W while operating) probably costs many thousands of euros in rocket fuel and emission taxes. The engineering time to properly fixate it onto the spacecraft, integrate the software, and test the whole thing cost probably a few ten thousands in salaries. Radiation may be a big problem for what's otherwise off-the-shelf hardware, that might mean the hardware costs much more (tens of thousands instead of a couple hundred euros potentially?) and gets significantly heavier from shielding, but I wouldn't know how much. Is that about right, am I missing something major and/or am I off on orders of magnitude somewhere?
dr_orpheus
8 days ago
Yeah, you got a lot of it and the ripple effect of things that go out from it. In addition to the extra mass of the camera and solar arrays, there is extra mass for the harnessing to connect the camera to the computer and engineering design for that as well. Integration of anything else on the spacecraft will have to go through Failure Modes Effects and Criticality Analysis (FMECA). Basically, this gets in to pretty detailed circuit design analysis and makes sure that any failure on the camera itself (like a short circuit or babbling idiot data bus) won't impact the rest of the spacecraft.
Potential cost of increased storage onboard the spacecraft if it is significant data volume. Cost of downlinking the data to the ground, time on the DSN is expensive. I think the cost data sheets for DSN usage are online and it depends on data rate, what dish you are using, etc. but costs for usage are on the order of thousands per hour and data rates from Jupiter are pretty slow.
The cost of the camera itself is likely on the order of a couple hundred thousand. I've seen similar costs for small radiation hardened cameras and star trackers. The difference in parts cost for some things can be absolutely insane. Passive electrical components certainly cost more, but for active circuits it can be insane. A radiation hardened equivalent of a $20 FPGA can be something like $20,000.
All told, cost of integration and use over the mission is likely at least a few million. But on a $1.1 billion mission it still doesn't seem like a lot.
wkrsz
7 days ago
TIL "babbling idiot" is a technical term https://www.wikidata.org/wiki/Q797603
> failure condition on a computer bus or network in which a malfunctioning node sends data at inappropriate times thus interfering with the communication of the working nodes
vlovich123
7 days ago
> A radiation hardened equivalent of a $20 FPGA can be something like $20,000
Has anyone actually tried putting up non-rad hardened equipment to measure how they perform? The Mars helicopter wasn't RAD hardened and used off the shelf parts & succeeded and the Mars atmosphere is not thick enough to meaningfully block the amount of cosmic rays hitting the surface.
I think NASA doesn't do a good job sometimes tolerating risk and then everything is treated as needing safety-levels of risk mitigation without considering that a 1/100th cost reduction will not generate as much in parts failures.
dr_orpheus
7 days ago
> I think NASA doesn't do a good job sometimes tolerating risk and then everything is treated as needing safety-levels of risk mitigation without considering that a 1/100th cost reduction will not generate as much in parts failures.
I do absolutely understand this impression of NASA. But I also think it gets inflated because the highest profile NASA missions that you hear about in the news are the most expensive and least risk tolerant missions. But there is pretty large spectrum in terms of cost caps and risk tolerance to NASA mission classes. I think generally in order of descending cost/risk tolernace it is: Human Spaceflight, Flagship (i.e. JWST, Mars Rovers), New Frontiers (Juno falls here), Discovery, Explorer, Mid-Explorer (MidEx), Small Explorer (SmEx), Venture.
For an example in the Venture class you can look at something like CYGNSS. Constellation of 8 spacecraft to better understand dynamics of hurricanes by looking at ocean wind speeds. This is done by mapping doppler delay of reflected GPS signals off of waves in the ocean. Important science, super cool technology with mostly automotive grade parts. ~$150 million for the whole mission that lasted about 7 years.
dr_orpheus
7 days ago
Yep, they do! I had some of this discussion on a thread talking about the Mars helicopter here that Goddard does a lot of radiation testing on commercial chips.
https://news.ycombinator.com/item?id=39175423#39182421
Lots of the new space, and smaller satellite companies use a lot of commercial parts. A lot of the flight data has shown even better results than the radiation testing (possibly due to added stress of testing at higher rates vs low rates over longer mission duration).
Generally speaking most of this is in LEO with a pretty low radiation environment. Whereas the area around Jupiter is one of the worst radiation environments in the solar system due to the radiation belts (like the Van Allen belts on steroids). This page on the Juno Radiation Vault says the spacecraft is exposed to an anticipated 20 Mrads of radiation. Whereas spacecraft in LEO are exposed to 0.1-10 krads per year depending on the orbit.
Also a fun fact, this is with Juno trying to limit exposure to the radiation belts as much as possible. [1]
[0] https://en.wikipedia.org/wiki/Juno_Radiation_Vault
[1] https://en.wikipedia.org/wiki/Juno_(spacecraft)#/media/File:...
#/media/File:Juno_trajectory_through_radiation_belts.png){kind=link}
vlovich123
7 days ago
Ok. That's a good point about the radiation belts. I hadn't considered that Jupiter's massive magnetosphere captures & concentrates a huge amount of solar energy & Juno is very close to it. Thanks for the additional info!
fecal_henge
7 days ago
Lots of work on this in the High Energy Physics community. Big experiments can design their own rad hard silicon, but everyone else has to test. Lots of space rated electronics is also qualified at far lower levels than we need. Upside ia that people are happy to share what they find:
chgs
7 days ago
If you’re spending nearly $1m on something to launch a camera do you really want to take the risk, so you can launch for 950000 instead of 970000?
vlovich123
7 days ago
It’s not risking the entire mission. Just the part the camera is should be risked. And from that perspective attach a camera to each thing you do and you’ve got a good shot of it working most of the time rather than spending outsized amount of resources to guarantee success. This is very similar to how SpaceX does rockets by the way so even if the cameras are useless you have a good shot at learning more things.
chgs
7 days ago
The $1m isn’t for the mission
Think of it another way, would you pay $99 for a camera which will work or $97 for a camera which might work.
grahamj
8 days ago
I’m reminded of the thread from the other day about “just” doing something.
We’ll just add a camera, no biggie!
Still, I’m very glad they did it. Arguably the second most beautiful planet :)
ClumsyPilot
8 days ago
> It was not included in the initial designs
That’s why NASA is poor and pentagon is rich.
To me as a taxpayer, if there are no cool pictures, it doesn’t exist.
If they were politically shrewd, camera would be the biggest instrument.
And the next probe that will dive into the sun would carry the bullet that killed Kennedy or a shot off piece from Trump’s ear.
slashdave
8 days ago
NASA's PR department makes the Pentagon look like amateurs.