An Up-Close Look At the Parker Solar Probe -- the Spacecraft That Will Skim the Sun's Surface (arstechnica.com)

schwit1 shares a report from Ars Technica, offering an up-close look at the Parker Solar Probe: This summer, NASA will launch the Parker Solar Probe, an impressively heat-resistant spacecraft destined to glide closer to the surface of the Sun than any spacecraft before it. It will fly within about 6 million kilometers of the searing surface, more than seven times closer than earlier craft. If all goes to plan, the craft will be hurtling at 724,205 km per hour and have its one-of-a-kind heat shield perfectly facing the surface as it makes those closest approaches. In about seven years, it will complete 24 orbits around the Sun and pass by Venus seven times. All the while, the Parker probe will collect a constellation of data to help answer scientists' burning questions -- and solve some sizzling mysteries -- about the orb of hot plasma that lights up our Solar System. Namely, it will try to help us finally understand why the Sun's atmosphere is 300 times hotter than its surface, which itself is a balmy 5,727C. This fact defies basic physics and to this day is unexplained. One of the leading hypotheses to account for the heat shift comes from famed physicist Eugene Parker, after whom the probe is named. In the mid-1950s, Parker theorized that the Sun's super-heated corona could be explained by a complex system of plasma, magnetic fields, and energetic particles that spark solar explosions called "nanoflares." Scientists are thirsty for close-up data on those potential explosions as well as the cascade of energy called solar wind. With that data, they can put their hypotheses to the test. And in addition to helping us understand coronal heat, data on these sunny phenomena could help clear up poorly understood space weather, which can wreak havoc on satellites and power lines here on Earth.

Comments

The sun doesn't really have a "surface"

[Anonymous Coward]

The plasma increases in density and temperature gradient until some arbitrarily defined point of human definition. If this thing is warping through there 7e5 km / hr then it's obviously nowhere near any surface.

Re:The sun doesn't really have a "surface"

[Geoffrey.landis]

True, and insightful. The sun has a visible surface, where the plasma becomes opaque. But the visible surface isn't a "surface" in any sense other than being visible-- it is a place where the density is actually far far less than the Earth's surface atmospheric density.

Cool to see the mission get some publicity --I was involved in the design (power system).

Re:The sun doesn't really have a "surface"

[Baloroth]

You send the spacecraft at night. I'm only kind of joking: you make a heat shield that creates an artificial "night" behind the shield. The only way for heat to transfer in space is radiation, so you just have to make sure that a) the more delicate components can't see the sun (so the sun can't heat them up directly), b) the shield doesn't transfer heat very well to the rest of the craft (it does have to be physically attached, but you can use very good insulators), and c) the shield poorly absorbs heat through radiation. a is easy, c is relatively easy (literally, you just paint it white), and b is tricky but very much possible. If the craft was an ideal black body, this wouldn't be possible, but fortunately it isn't.

Hide behind carbon [Re:The sun doesn't rea...]

[Geoffrey.landis]

What kind of materials are used that can take that kind of heat, even a fraction of the heat destroys most electrical component.

Carbon. Sublimates around 3825C or so.

Most of the spacecraft hides behind the carbon shadow shield-- almost all the instruments don't need to look toward the sun (the main interest is plasma and fields). The exception is the solar array (my part of the project!)-- this doesn't work unless it is in the sunlight :). But the sunlight is intense enough that we only need a tiny bit of the array to be illuminated, so we retract most of it into the shadow, tilt the part that does see the sun, and use concentrator solar cells that are actively cooled to keep temperatures reasonable.

Honestly, it is people like you that keep me coming back to /. , I have yet to find a single site to replace it.(sure there is hacknews and reddit...)

Thanks.