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#40
by
zhangmdev
on 01 Sep, 2018 14:18
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A Chinese scientist says the country's solar radio heliograph is likely to cooperate with NASA's recently launched Parker Solar Probe to study the Sun.
"The Chinese Spectral Radioheliograph (CSRH), built at Ming'antu, a radio quiet region in north China's Inner Mongolia Autonomous Region, consists of 100 antennas with different frequency spectra covering an area of 10 square km. It can monitor solar activities on a wide imaging resolution spectrum."
" the observation range of the CSRH and the Parker Solar Probe will overlap and it's possible that the two will cooperate in the future for specific scientific tasks. "
http://www.china.org.cn/china/Off_the_Wire/2018-08/14/content_58736256.htmNever heard about this project. Tried and failed to find more info about this cooperation.
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#41
by
Rondaz
on 05 Sep, 2018 14:37
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Parker Solar Probe Continues Successful Commissioning Operations
September 5, 2018
Parker Solar Probe continues to bring its instruments and secondary systems online — slightly ahead of schedule — as it speeds away from Earth.
On Friday, Aug. 31, flight controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland performed a second planned Trajectory Correction Maneuver (TCM-2), a thruster burn which lasted for seven minutes and five seconds. This maneuver, which was executed with a high degree of precision, adjusted the direction of the spacecraft to position it for its Venus flyby on Oct. 3, when it will use Venus’ gravity to shed speed and draw its orbit closer to the Sun in preparation for its first solar approach.
On Sept. 2, four two-meter electric field antennas, part of the FIELDS instrument suite, were deployed. These antennas (as well as a fifth, which is mounted on the long boom at the other end of Parker Solar Probe) need to be extended away from the spacecraft to accurately measure the electric fields of the corona. These four antennas are not protected by Parker Solar Probe’s Thermal Protection System, or heat shield, so they are made of niobium C-103, a high-temperature alloy that can withstand the intense solar heat.
Just a few hours after the FIELDS antennas were deployed, the Solar Wind Electrons Alphas and Protons (SWEAP) investigation team successfully opened the covers of two instruments, the Solar Probe Analyzer (SPAN) instruments. The SPAN instruments are used to measure the solar wind when it is coming in at an angle relative to the spacecraft.
Before opening the SPAN instrument doors, the team ramped up high voltages on the Solar Probe Cup (SPC) instrument, also part of SWEAP. Solar Probe Cup measures the thermal solar wind plasma flowing radially from the Sun — requiring this instrument to be mounted outside the heat shield and pointed directly at the Sun. Like the FIELDS antennas, Solar Probe Cup is constructed of niobium C-103.
Other systems and instruments have completed checkouts as well. The spacecraft’s high gain antenna — which will be used to send high-rate science data to Earth — has been moved through its full range of motion.
EPI-Lo and EPI-Hi, the two Energetic Particle Instruments that make up the IS☉IS suite (pronounced “ee-sis” and short for Integrated Science Investigation of the Sun), have been turned on and have completed low voltage checks.
The Wide-field Imager for Solar Probe (WISPR) instrument has been turned on and has taken closed-door test images to calibrate the systems and imagers.
“The spacecraft continues to perform as designed, and thanks to the team’s careful planning and execution, we’re commissioning instruments slightly ahead of schedule,” said APL’s Andy Driesman, Parker Solar Probe project manager.
“The science team is excited to begin the investigation phase of the mission,” said Nour Raouafi of APL, Parker Solar Probe project scientist. “We’re looking forward to seeing this initial science data and getting our first look at what we know will be many discoveries that Parker Solar Probe will make.”
As of 12 p.m. EDT on Sept. 4, Parker Solar Probe was more than 15 million miles from Earth, travelling at about 44,700 miles per hour (72,000 kilometers per hour).
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#42
by
lamid
on 05 Sep, 2018 22:48
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#43
by
jbenton
on 05 Sep, 2018 23:57
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Thanks for all that
And yes, it's strange, the difference in probe weight is 685kg - 478kg and rockets 733,000 - 587,000kg. The gravity well is strong.
"The Force [of gravity] is strong with this one" (Earth)
I apologize for cracked English, I was not born in an English-speaking country
As far as I can tell, your English is perfect
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#44
by
envy887
on 06 Sep, 2018 02:58
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Energy is close, but velocity is pointing to a quite different direction. To fly inward along an very elongated oribit, it must cancel the sideway movement of the Earth. The original Solar Probe planned to use Atlas 551 Star 48B. It was going to fly outward to meet Jupiter.
C3 only relates to the Earth; it is a measure of the leftover energy after going a very far distance from Earth.
The direction that this distance is traveled does not change the C3, so it doesn't matter if it's going into a lower or higher heliocentric orbit.
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#45
by
lamid
on 09 Sep, 2018 04:51
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...
On Friday, Aug. 31, flight controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland performed a second planned Trajectory Correction Maneuver (TCM-2), a thruster burn which lasted for seven minutes and five seconds.
...
a second planned Trajectory Correction Maneuver (TCM-2), a thruster burn which lasted
for 35.2 seconds.
Editor’s note: The original version of this post misstated the length of the TCM-2 thruster burn. This version has been updated with the correct figure.
https://blogs.nasa.gov/parkersolarprobe/2018/09/05/parker-solar-probe-continues-successful-commissioning-operations/
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#46
by
lamid
on 11 Sep, 2018 08:32
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From the
https://ssd.jpl.nasa.gov/horizons.cgi I made the chart of the 24th Parker Solar Probe around the Sun
the result
0,04589886AU 6866372km min 19.jun.2025 05:27
190,76580km/s max 19.jun.2025 08:41
I do not understand why is the minimum distance and max speed at another time?
SPACECRAFT TRAJECTORY
Name Start (TDB) End (TDB)
---------------------------------------- ----------------- -----------------
psp_20180812_20250831_v034_RO1_TCM1.V0.1 2018-Aug-12 08:17 2025-Aug-31 09:18
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#47
by
Steven Pietrobon
on 11 Sep, 2018 10:01
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I do not understand why is the minimum distance and max speed at another time?
The speed must be relative to a point which is not the centre of the Sun, otherwise they should coincide. Perhaps they are using Earth relative speed.
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#48
by
kdhilliard
on 11 Sep, 2018 13:28
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I do not understand why is the minimum distance and max speed at another time?
lamid, it looks like you are computing with respect to "Observer Location: Solar System Barycenter (SSB) [500@0]" and plotting "Quantities: 20.1 (delta = Range of target center with respect to the observer) & 22.2 (VmagOb = Magnitude of target center velocity wrt the observer)".
Yes, everything is orbiting about the barycenter, but the PSP is so close to the Sun at that point that you can't treat it as a 2-body problem between the probe and the barycenter, so its range is not minimizing at the same time its speed is maximizing.
It is close enough to the Sun that you can get away with treating it as a 2-body problem between the probe and the Sun, and if you plot "Quantities: 19.1 (r = Heliocentric range) & 22.1 (VmagSn = Magnitude of target center velocity wrt Sun)", then you will find the extrema concide at 2025-Jun-19 08:40 with r=0.045873380734 au, VmagSn=VmagOb=190.7704 km/s.
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#49
by
lamid
on 11 Sep, 2018 14:01
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yes, solar system barycenter.
If use Sun (body center) [500@10]
Result>
0,04587338AU 6862560km min 19.jun.25 08:41
190,77036km/s max 19.jun.25 08:41
Note:
I know, this is a planned trajectory, and the outcome will depend on the success of trajectory corrective maneuvers (TCM).
But the PSP will run around the solar system's barycenter, not the Sun.
And the distance of Sun to Solar System barycenter is 1 048 272 km (19.jun.2025)
Edit 2018-09-13:
When I look at the
https://ssd.jpl.nasa.gov/horizons.cgiresult:
Barycenter is in oposite side the Sun.
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#50
by
lamid
on 12 Sep, 2018 08:21
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Parker Solar Probe 24th perihelion in the coordinates of the Solar System Barycenter
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#51
by
Rondaz
on 14 Sep, 2018 19:54
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Parker Solar Probe’s Solar Array Cooling System Fully Activated
On Sept. 13, Parker Solar Probe’s first-of-its-kind water-cooled Solar Array Cooling System (or SACS) was made fully operational. The SACS will protect Parker Solar Probe’s solar arrays — responsible for powering the spacecraft — from the intense heat of the Sun.
Though the solar arrays rely on the Sun’s energy to create electrical power for the spacecraft, they’re also very sensitive to overheating, and Parker Solar Probe is the first scientific mission to use a water-cooled solar array thermal management system. Water flows through mini-channels embedded in the solar arrays to absorb heat, then flows into four radiators to release that heat into space. This keeps the solar panels cool while near the Sun, allowing them to efficiently generate power for the spacecraft.
Though the Sun-facing side of Parker Solar Probe’s heat shield will reach temperatures as high as 2,500 degrees Fahrenheit when the spacecraft is close to the Sun, the SACS will keep the solar arrays — partially exposed to the Sun’s direct radiation — at less than 302 degrees.
The Solar Array Cooling System uses large black radiators, at the top of the spacecraft, to cool water that flows through portions of the solar arrays, bottom left. Credit: NASA/Johns Hopkins APL/Ed Whitman
As planned, the cooling system came partially online shortly after launch on Aug. 12. Roughly one hour after Parker Solar Probe’s 3:31 a.m. EDT launch, the spacecraft autonomously released the launch locks on its two solar arrays and deployed the panels. The spacecraft then released approximately two-thirds of a gallon of deionized water from a heated tank into two of four large radiators, mounted just below the spacecraft’s heat shield.
Then on Sept. 13, at around 11 p.m. EDT — when the spacecraft had reached a distance of about 84 million miles (135 million kilometers) from the Sun — the remaining one-third of a gallon of water was released, activating the last two radiators and making the SACS fully operational. These events were controlled by the mission operations team at the Johns Hopkins Applied Physics Lab in Laurel, Maryland.
“There are a number of technological breakthroughs on Parker Solar Probe that make the mission possible,” said APL’s Andy Driesman, project manager for mission. “The Solar Array Cooling System is really the heart and circulatory system of the spacecraft. Without it, the solar arrays would not survive the heat from the Sun, and we would not be able to operate the instruments that will explore the Sun’s corona and the systems that protect the spacecraft from the intense solar environment.”
As of 12 p.m. EDT on Sept. 14, Parker Solar Probe was 21 million miles (34 million km) from Earth, traveling at about 51,000 miles per hour (82,000 kph). Track the spacecraft’s progress online.
By Geoff Brown
Johns Hopkins University Applied Physics Lab
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#52
by
plutogno
on 19 Sep, 2018 19:10
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#53
by
jbenton
on 20 Sep, 2018 05:30
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Thanks for the link; the pictures are beautiful!
caption from the article:
The right side of this image — from WISPR’s inner telescope — has a 40-degree field of view, with its right edge 58.5 degrees from the Sun’s center. The left side of the image is from WISPR’s outer telescope, which has a 58-degree field of view and extends to about 160 degrees from the Sun. There is a parallax of about 13 degrees in the apparent position of the Sun as viewed from Earth and from Parker Solar Probe. Credit: NASA/Naval Research Laboratory/Parker Solar Probe
Where is the inner telescope in relation to the outer telescope. I struggle to imagine a telescope within a telescope...
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#54
by
lamid
on 20 Sep, 2018 05:44
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WISPR (Wide-field Imager for Solar Probe)
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#55
by
Yeknom-Ecaps
on 28 Sep, 2018 21:38
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Announced "First light" took place for WISPR on September 9 ......
seems like SWEAP/SPAN was on September 8?
any idea for the other instruments
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#56
by
Rondaz
on 02 Oct, 2018 14:28
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Fall 2018 Milestones for Parker Solar Probe
Sarah Frazier October 2, 2018
We like to call Parker Solar Probe the coolest, hottest, fastest mission under the Sun — and fall 2018 will prove why. Here are a few mission milestones to look forward to over the coming months.
Oct. 3, 2018 (about 4:45 a.m. EDT) — Parker Solar Probe performs its first Venus gravity assist. This maneuver — to be repeated six more times over the lifetime of the mission — will change Parker Solar Probe’s trajectory to take the spacecraft closer to the Sun.
Oct. 29, 2018 — Parker Solar Probe is expected to come within 27 million miles of the Sun. This is the record currently held by Helios 2, set in 1976.
Oct. 30, 2018 — Parker Solar Probe is expected to surpass a heliocentric speed of 153,454 miles per hour. This is the record for fastest spacecraft measured relative to the Sun, set by Helios 2 in 1976.
These speed and distance estimates could change after Parker Solar Probe performs its Venus gravity assist on Oct. 3.
Oct. 31 – Nov. 11, 2018 — Parker Solar Probe performs its first solar encounter. Throughout this period, the spacecraft will gather valuable science data. It will not be in contact with Earth because of the Sun’s interference and the orientation needed to keep the spacecraft’s heat shield between it and the Sun. The spacecraft is expected to reach its closest approach on Nov. 6. Like the distance and speed records, this estimate could change after the Venus gravity assist.
December 2018 — Parker Solar Probe will downlink the science data gathered during its first solar encounter.
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#57
by
K-P
on 02 Oct, 2018 17:01
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What is the flyby distance of Venus tomorrow?
And what about on subsequent flybys? Similar?
Thanks.
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#58
by
dsmillman
on 02 Oct, 2018 17:19
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#59
by
lamid
on 03 Oct, 2018 05:49
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