Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New images of Jupiter

missionjuno.swri.edu

Post reply on HN
Print view View original

61–70 of 85 posts

Re: New images of Jupiter

#61

Post by vlovich123 »

dr_orpheus wrote: post #51
Aachen wrote: post #47

Earlier quoted context omitted.

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 salarie…

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…

> 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.

Re: New images of Jupiter

#62

Post by dr_orpheus »

vlovich123 wrote: post #61
dr_orpheus wrote: post #51

Earlier quoted context omitted.

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…

> 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…

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:...

Re: New images of Jupiter

#63

Post by fecal_henge »

vlovich123 wrote: post #61
dr_orpheus wrote: post #51

Earlier quoted context omitted.

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…

> 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…

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:

https://arxiv.org/pdf/1912.01742.pdf

https://twiki.cern.ch/twiki/bin/view/Main/RAD-HARD-COMP

Re: New images of Jupiter

#66

Post by magicalhippo »

dr_orpheus wrote: post #46
foobarbecue wrote: post #40

Earlier quoted context omitted.

If you want to go faster, you need more fuel, and eventually you max out the biggest rocket available. Clipper is the most massive planetary probe ever-- they had to use falcon heavy in fully expendable mode to get it up there.

Yep, for reference Europa Clipper is 6,065 kg [0]. It is an absolutely massive interplanetary probe. It is getting close in size to some of the largest GEO communication satellites. And to get it out to Jupiter they definitely need some of the gravity assist trajectories. On the opposite end of the spectrum, New Horizons was only 478 kg [1] and still holds the record for the fastest thing ever launched from Earth. It…

Cassini[1] was quite massive too at launch, at 5712 kg. Though to be fair, 320 kg was due to the Huygens[2] probe it carried with it.

[1]: https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

[2]: https://en.wikipedia.org/wiki/Huygens_(spacecraft)

Re: New images of Jupiter

#67

Post by dr_orpheus »

vlovich123 wrote: post #61
dr_orpheus wrote: post #51

Earlier quoted context omitted.

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…

> 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…

> 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.

Re: New images of Jupiter

#68

Post by vlovich123 »

dr_orpheus wrote: post #62
vlovich123 wrote: post #61

Earlier quoted context omitted.

> 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…

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 tes…

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!

Re: New images of Jupiter

#69

Post by kulahan »

openrisk wrote: post #33

Alien feel (and even unsettling at times). I guess we have grown used to this by now, but from the Moon landing pictures, to the Mars rovers and the various asteroid and planetary missions the objects of the Solar system are now vivid, complex and above all, "real" places.

The photos of Pluto from the New Horizons mission are stunningly beautiful. Who knew you could fall in love with a frozen rock?

Re: New images of Jupiter

#70

Post by generic92034 »

latexr wrote: post #50
JoeAltmaier wrote: post #29

Juno was something about radar - penetrating the cloud layers to see what was below. In college my son worked on the FFT engine that processed the radar data. He has code circling Jupiter!

That would be a hilarious (and confusing) bumper sticker. When other parents say “my son is an honour student” you can smugly reply “yeah, but does he have code circling Jupiter?” Congratulations, by the way. I’m being (trying to be) funny but I genuinely think that is cool and a reason to be proud.

On the other hand, depending on their development, the Jovians might think that everything at all is circling Jupiter. :D
Post reply on HN