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Comment by netfire | Hacker News Reader

The article makes it sound like there is no possible way for the probe to melt. Is this actually the case? Is there no possibility that manufacturer defects or a solar anomaly that could cause unexpected problems?

I don’t want to downplay the good design and engineering that went into this, but should we be so confident without actually having done something like this thousands of times?

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> Is there no possibility that manufacturer defects or a solar anomaly that could cause unexpected problems?

There sure is. At least two of the systems (positioning and water cooling) are active systems that could fail.

> but should we be so confident without actually having done something like this thousands of times?

"we" are confident enough that we rely on it to protect a > 1 billion USD probe. What's the use in adding a lot of ifs and maybes to some piece of marketing/explanation?

If it fails, adding some ifs and maybes to a marketing video won't really change anything.

Doesn’t it undermine the credibility of NASA if something goes wrong? The public who is the audience for this article is also paying the bills (through taxes). I’d settle for just changing “won’t melt” to “shouldn’t melt”. I think that appropriate for something that’s never been attempted.

Either way we’re chucking lots of money at the sun so if it fails we still learn something, not to mention developed a lot of technologies along the way.

For sure, but it would be a shame if NASA lost confidence and trust (and possibly funding) with their stakeholders (the public), because they weren’t more upfront about the potential risks. As a scientific organization that has experienced significant (and expensive) failures before, I expect better.

It seems like you want to discredit NASA now ("shouldn't melt") vs some imagined possibility("won't melt" but it does). With the amount of design, analysis, testing, and independent review and verification of the systems, backup systems, triply redundant systems, and autonomy, we can be as sure of it not melting as we can be sure of anything. And we certainly spent a large amount of money on this (about 1/10th of the World Cup), but in performance and value per $, it's a great deal.

Not at all. I expect NASA has done as much due diligence, planning, testing, and verification as possible. I just don’t think they are being upfront as they should be about the possible risks for a previously unattempted scientific endeavor. We’ve had massive failures (including NASA itself), in environments that are much better understood and with systems that have actually had exposure to those environments.

I also didn’t intend on “shouldn’t melt” to be taken sarcastically. I was trying to show how I would like something changed in the article. Probably a bad use of quotes on my part...

(former software engineer on PSP here) It's a certainty that it will melt eventually, but that's not a satisfying answer to the question "why won't it melt?" The satisfying answer is "for the time period when it won't melt, it won't melt because of..."

It's worth noting that the initial orbits will all be fairly far out and they will ease into the tighter orbits after a few years of testing.

Manufacturing defects are part of engineering - they're good at this and there will be multiple scans done of the shield before it's sent up (x-rays etc) to check for defects.

But I'm also curious about what happens in the event of a solar flare or similar - from an engineering standpoint, what's their safety margin? Solar density goes up two hundred percent?

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