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AkaSci 🛰️

NASA’s Parker Solar Probe will make its 22nd close approach of the Sun tomorrow Dec 24, 2024 at 11:53 UTC. At perihelion, it will be at a record distance of just 6.1 million km from the solar surface, traveling at a record speed of 692,018 km/h, beating its previous record of 7.26 million km and 635,300 km/h during perihelion 21 on Sep 30.

For comparison, the perihelion of planet Mercury is at 45.3 mil km.

parkersolarprobe.jhuapl.edu/Ne
en.wikipedia.org/wiki/Parker_S

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NASA’s Parker Solar Probe (PSP) holds the record for the fastest spacecraft, beating its nearest rivals by a considerable amount.

For comparison, the table below shows speeds for various spacecraft, planets and satellites.


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NASA’s Parker Solar Probe is named after pioneering solar and plasma physicist Eugene N. Parker (Jun 10, 1927 – Mar 15, 2022). It is the first NASA spacecraft named after a living person.

In the 1950s, Parker proposed the existence of the solar wind and predicted the shape of the solar magnetic field. In 1987, he proposed nanoflares to explain why the corona is much hotter than the Sun’s surface.

en.wikipedia.org/wiki/Eugene_P
parkersolarprobe.jhuapl.edu/Ne

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How does the Parker Solar Probe keep its instruments at room temp, while venturing so close to the blazing Sun?

It does so using an innovative 2.3 m heat shield, which uses space-age materials to keep the instruments at 29°C while the Sun facing heat shield heats up to 1,370°C. Most of the heavy-lifting is done by a 11.4 cm thick layer of carbon foam, typically used in the medical industry for bone replacement.
See diagram below for some details.

hub.jhu.edu/2018/08/06/parker-

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Here is Betsy Congdon of Johns Hopkins Applied Physics Lab, the Lead Thermal Engineer on Parker Solar Probe's heat shield, dramatically demonstrating the insulation and heat dissipation properties of the heat shield.

youtube.com/watch?v=BKinVmBoIr
More info at nasa.gov/solar-system/travelin
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The following diagram illustrates the size of the Sun, the distance between the Sun and the Parker Solar probe and the edge of the Corona, the Sun's "atmosphere." The edge/zone is known as the Alfvén surface.

The Parker Solar Probe penetrated the Sun's Corona during its 8th flyby on April 28, 2021, at 18.8 solar radii (13 million km) above the solar surface. Today's encounter was at less than half that distance.

space.com/26381-sun-atmosphere
parkersolarprobe.jhuapl.edu/Ne
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The graphic below shows the timeline of events during perihelion 22 of the Parker Solar Probe.

For 11 days around perihelion, PSP collects science data but maintains radio silence. Data is downlinked once the spacecraft is about 0.25 AU away from the Sun.

During these 11 days, PSP is on its own, running instruments, storing data, keeping the shield pointed at the Sun, angling solar arrays to prevent overheating, thermal mgmt, ...

thesuntoday.org/missions/parke

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An hour before close flyby of the Sun at 11:53:48 UTC, here is the state of the Parker Solar Probe (PSP) -
Speed: 685,760 km/h
Distance from Sun's Surface: 6.185 million km
Heat Shield Temperature: 941.1°C

Note that these are calculated values; the PSP is not communicating with earth at this point.

parkersolarprobe.jhuapl.edu/
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At perihelion moments ago at 11:53:48 UTC, this was the state of the Parker Solar Probe (PSP), with all instruments focused on the Sun -
Speed: 686,718 km/h
Distance from Sun's Surface: 6.167 million km
Heat Shield Temperature: 941.7°C

Note that these are calculated values; the PSP is not communicating with earth at this point.

PSP is now in an 88 day orbit around the Sun and will make at least 2 more similar close encounters of the Sun in 2025.

parkersolarprobe.jhuapl.edu/
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It takes 55 times more energy to go to the Sun than it does to go to Mars!

That's because earth is speeding along its orbit at v = 107,208 km/h and so is the probe before launch. It carries an
Angular Momentum L = mvr
m = mass
v = velocity
r = radius

PSP had to shed a large part of this sideways speed using a big rocket and multiple flybys of Venus. As the probe got closer to the sun, its speed increased due to the law of Conservation of Angular Momentum.

nasa.gov/solar-system/its-surp
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NASAIt's Surprisingly Hard to Go to the Sun - NASAThe Sun contains 99.8 percent of the mass in our solar system. Its gravitational pull is what keeps everything here, from tiny Mercury to the gas giants to

Let's hope that the Parker Solar Probe managed to surf thru some active solar flares (without getting roasted of course).

The Sun is now officially at peak activity (aka solar maximum) of Solar Cycle 25.

We will not discover PSP's status until about 6 days from now when PSP starts transmitting data to earth. If all is well, then a short beacon signal will also be sent by PSP on Dec 27.

swpc.noaa.gov/communities/spac
swpc.noaa.gov/news/joint-solar
svs.gsfc.nasa.gov/14683
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The NASA Parker Solar Probe broke radio silence last night after its record close flyby of the Sun last Sunday.

It sent a planned short beacon tone signal via NASA DSN Deep Space Station 34 in Canberra to the operations team at JHUAPL in Laurel, MD. The signal was received just before midnight EST On Dec 26.

Next, the spacecraft is expected to send back detailed status data on Jan 1 and science data over the next few weeks.
:mastodance:

parkersolarprobe.jhuapl.edu/Ne
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Note that the beacon tone sent by the Parker Solar Probe sent last night used the Low Gain Antenna (LGA), which is either omnidirectional or has a very wide beam. The telemetry xmission on Jan 1 will also use the LGA.

It will probably be a while before the spacecraft is oriented such that the High Gain Antenna (HGA) is pointed at Earth and can be used to downlink science data.

The diagram below shows the locations of the PSP, the Sun and Earth on Dec 26 and Jan 1.

eyes.nasa.gov/apps/solar-syste
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A week after the NASA Parker Solar Probe (PSP) made its closest and fastest flyby of the Sun, it has been communicating with Earth using its low-rate X-band transceiver since yesterday, sending telemetry and spacecraft health data to the control center at JHUAPL in Maryland via NASA's Deep Space Network (DSN).

Science data will be downloaded via the high speed Ka-band link in the weeks to follow.

eyes.nasa.gov/apps/dsn-now/dsn
eyes.nasa.gov/apps/solar-syste

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A week after the NASA Parker Solar Probe (PSP) made its closest and fastest flyby of the Sun, it is at a healthy distance from the Sun and the heat shield temperature has dropped from 942°C to 158°C.

As indicated in the previous post, it is currently sending telemetry data to Earth at 40 bits/s.

parkersolarprobe.jhuapl.edu/
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5 weeks after the NASA Parker Solar Probe (PSP) made its closest and fastest flyby of the Sun, it is nearing aphelion and sending science data to earth over its high data-rate Ka-band link at 147 kbps.

eyes.nasa.gov/apps/dsn-now/dsn
eyes.nasa.gov/apps/solar-syste

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@AkaSci Former NASA Assistant Administrator for Science Thomas Zurbuchen writes about the Parker Solar Probe close pass in a WaPo opinion piece:
archive.ph/Q4Cyt

@rich @AkaSci Yup, fastest by a very long way! It's currently shifting so fast that it could cross from the Earth to the Moon in about 33 minutes (it took the Apollo missions closer to 33 hours).

@cstross @rich
Please take a look at post #2 in this thread for some interesting speed comparisons 🛰️
fosstodon.org/@AkaSci/11370504

@AkaSci I hear Bruce Springsteen while close flyby : „I‘m on Fire“
🔥😘

@AkaSci Fast: Earth to Moon in half an hour ish.
Impressive project.

@AkaSci > Speed: 686,718 km/h

I've always wondered what this means for things in space. With everything being relative to other things. Ground speed doesn't exist there, does it? Does it actually have any value?

@KoosPol
This speed value is relative to the Sun, which is a good reference point to compare speeds in the immediate space around us.

@AkaSci after wistling Springsteen’s “I’m on fire “ and the return of the probe from sun I change my song into “There’s always a Sun” from the Stranglers 😚 finally Harrison/Beatles waits me for “Here comes the Sun” ☀️

@AkaSci I'm honestky impressed by the speed! I double (or triple) checked that the "," is the thousands-separator (in germany it's exactly vice versa: .dotfor thousands, comma for decimals

@AkaSci
There is much at stake.
My name is in that Probe.

@AkaSci aren’t all materials made since the 60’s ‘space age’? Seems like maybe we need a new term. 🤔

@AkaSci The fastest man made object ever! Hard to imagine what such a speed would look like. What would it to take to get humans up to such a velocity I wonder, is it even possible?

@AkaSci concerning climate change our star became a huge risk. This solar probe becomes a great chance to learn about the source of all😙

@AkaSci Thanks for the cool graphics @AkaSci and good luck #Parkersolarprobe 👍