NASA's Parker Solar Probe Completes Historic Christmas Eve Flyby of the Sun (livescience.com) 21
NASA's Parker Solar Probe made a historic approach on Christmas Eve, flying within 3.8 million miles of the Sun at a record-breaking speed of 430,000 mph. It marks humanity's closest encounter with a star. Live Science reports: Mission control cannot communicate with the probe during this rendezvous due to its vicinity to the sun, and will only know how the spacecraft fared in the early hours of Dec. 27 after a beacon signal confirms both the flyby's success and the overall state of the spacecraft. Images gathered during the flyby will beam home in early January, followed by scientific data later in the month when the probe swoops further away from the sun, Nour Rawafi, who is the project scientist for the mission, told reporters at the Annual Meeting of the American Geophysical Union (AGU) earlier this month.
Parker launched in 2018 to help decode some of the biggest mysteries about our sun, such as why its outermost layer, the corona, heats up as it moves further from the sun's surface, and what processes accelerate charged particles to near-light speeds. In addition to revolutionizing our understanding about the sun, the probe also caught rare closeups of passing comets and studied the surface of Venus. On Christmas Eve, scientists expect the probe to have flown through plumes of plasma still attached to the sun, and hope it observed solar flares occurring simultaneously due to ramped-up turbulence on the sun's surface, which spark breathtaking auroras on Earth but also disrupt communication systems and other technology. "Right now, Parker Solar Probe has achieved what we designed the mission for," Nicola Fox, the associate administrator for NASA Science Mission Directorate at NASA Headquarters in Washington, D.C., said in a NASA video released on Dec. 24. "It's just a total 'Yay! We did it' moment."
Parker launched in 2018 to help decode some of the biggest mysteries about our sun, such as why its outermost layer, the corona, heats up as it moves further from the sun's surface, and what processes accelerate charged particles to near-light speeds. In addition to revolutionizing our understanding about the sun, the probe also caught rare closeups of passing comets and studied the surface of Venus. On Christmas Eve, scientists expect the probe to have flown through plumes of plasma still attached to the sun, and hope it observed solar flares occurring simultaneously due to ramped-up turbulence on the sun's surface, which spark breathtaking auroras on Earth but also disrupt communication systems and other technology. "Right now, Parker Solar Probe has achieved what we designed the mission for," Nicola Fox, the associate administrator for NASA Science Mission Directorate at NASA Headquarters in Washington, D.C., said in a NASA video released on Dec. 24. "It's just a total 'Yay! We did it' moment."
I saw what you did (Score:2)
Not that the censor trolls wanted me to. Why do they have so many mod points to spew?
Anyway, the thing that struck me about the story is not what you did (and which I managed to see anyway, notwithstanding the censors), but what the story did with the speed of the probe to make is sound fast. Wow! So many miles per hour! That's great!
But if you check it against the speed of light in miles per hour the speed comes out as 0.0006 something. And we only got it that fast by nearly falling into the sun.
I am curio
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I think 10g is more in the "some humans can survive this" range than "many humans can function at this". Depending on build - and build is important, height as well as girth - some people might struggle to function at 2 or 3 g without being clinically obese.
The maximum g the probe experienced was almost certainly during launch, where the "shaking tables" of the "shake and bake" part of testing the flight models go to 6 or 7 g, AIUI, with the lateral g b
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But isn't the probe experiencing a lot of "tidal force" G now? I should have clarified that's what I was thinking about, though I have no idea how large the probe is nor how it is configured.
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Taking one approach : The force is going to turn the spacecraft around, but it's going to take about a half-circle at the closest approach to do it
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I think your envelope equation is roughly saying "not significant".
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It might be a different calculation for, say, a long-arm space frame which gets deployed in space - like the arm supporting the secondary mirror on the JWST. But with that being at a gravity-potential flat spot (a different way of saying "Lagrange point), the gradients in potential are going to be low, which means the forces (gravitational and tidal) induced are also going to be low. I'm sure someone did the calculations, made sure the arm was stiff-enough, and included adjus
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Just the ACK and thanks.
Hm (Score:3)
it sounds like we still don't know whether the prove completed the flyby or not. We can assume it did based on trajectory, but it sounds like we won't actually know until the 27th.
Re:Hm (Score:5, Interesting)
The probe will certainly continue on the predicted trajectory.
The risk is that electronics may have failed from the heat.
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Well, small probability of smacking into a previously undetected "sun-grazer" comet. Very small probability, but solar telescopes see dozens of these a year (hundreds even?) so it was probably worthwhile doing the calculation for general population statistics, and to avoid known examples. AIUI, the collision-avoidance protocols for "MU-69" (now "486958 Arrokoth") had a "gi/no-go" decision around a day before closest approach, and they didn't hit
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I wondered if they'd got a "heartbeat" signal going on one of the transmitters that is furthers from the noisy sections of the corona's emission. But I haven't been bothered enough to find out.
Ah ... I figured it.
The transmitters - well, antennae - need to be on the side not protected by the thermal shield. The thermal shield needs to be oriented (fairly closely) to the Sun. Because they're at perihelion, the orientation of the spacecraft with respect to the spacecraft-Sun direction is
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Yes, I'd say surviving the encounter is a requirement to qualify for completing a flyby.
430,000 mph. (Score:2)
What is that in parsecs per fortnight?
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Trying to make it relatable? They should have reported the speed in terms of how long you'd have to press the accelerator on a Ford pickup to get to that speed.
"Look ma! No brakes!"
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Now, that actually *is* a useful metric.
Who cares (Score:2)
Vicinity to the sun? (Score:1)
> "Mission control cannot communicate with the probe during this rendezvous due to its vicinity to the sun [sic] ..."
Wait ... "vicinity to the sun"? Don't you mean "proximity to the sun", or "vicinity of the sun"? But one thing for sure -- this piece wasn't written by ChatGPT, which wouldn't have made this elementary error.
It survived ! (Score:2)
The link is on my phone. Do your own searches.
It's closer than New Horizons, so I'd expect the fly-by data to take less than 2 years to transmit. Probably a lot less, as the probe is moving to a lower-background-noise area, and so improving signal:noise ratio, while NH was under steadily decreasing SNR conditions.