![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
What does it mean to be the "fastest" object when something is in space?
That is, speed relative to what? — Preceding unsigned comment added by 93.34.50.240 ( talk) 08:40, 17 August 2012 (UTC)
Please update if this is the correct link. http://spacenews.com/41380solar-probe-plus-nasas-mission-to-the-fires-of-hell-trading-atlas-5-for/
BenjaminJMeyer ( talk) 08:30, 2 January 2015 (UTC)
Hello fellow Wikipedians,
I have just modified 4 external links on Parker Solar Probe. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 16:58, 10 September 2017 (UTC)
I know relativity is needed to explain long term precession of Mercury. I'm curious if relativistic corrections are needed for a mission like that? Tom Ruen ( talk) 19:45, 22 November 2017 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Parker Solar Probe. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 18:57, 12 January 2018 (UTC)
Of what materials is the Parker Solar Probe to be constructed? MaynardClark ( talk) 17:59, 21 August 2017 (UTC)
Various different materials. I don't have to whole list. But that, as well as a description of the spacecraft and the instruments, should really be added to this page. Fcrary ( talk) 18:03, 21 August 2017 (UTC)
Can we have details on the design of SACS (Solar Array Cooling System)? What I have read so far is that it uses one gallon of water and there's a pump (not heat pipes). But how is the water kept from freezing when the spacecraft is far away from the Sun? Is it stored in a heated reservoir and the system is bled (possibly purging some filler gas?) once the probe gets close enough to the Sun for water not to freeze? Or perhaps it's naturally kept above freezing point at all times as it circulates in the exposed solar panels? And how is thermal expansion (of water) compensated for?
There is currently a sidebar diagram showing Voyager 2 info, with the following caption:
Plot of Voyager 2's heliocentric velocity against its distance from the Sun, illustrating the use of gravity assist to accelerate the spacecraft by Jupiter, Saturn and Uranus.[23] Using the same technique but with Venus, Parker Solar Probe will decelerate to lower its orbit.
This isn't really useful in this article; it feels like someone threw it in because it's available and somewhat related. Plus, Section 2 is really unbalanced at this point, with the sidebar being far taller than the body text.
Would it be appropriate to remove the diagram? -- Dan Griscom ( talk) 13:04, 11 August 2018 (UTC)
How much did that probe cost? — Preceding unsigned comment added by 78.49.247.38 ( talk) 09:19, 15 August 2018 (UTC)
@ Mfb: Re: your edit, FYI that was caused by a change in column heading. It was originally perihelion distance, and was accurate for the launch orbit. (But of course, the spacecraft was nowhere near perihelion; it launched from 1.0 AU, not 0.278.) I changed the column heading to "perihelion" to help untangle the frequent confusion in various sources between distance-from-Sun-center and altitude-above-Sun-surface. I thought using "perihelion" for the former and "altitude" for the latter and avoiding the ambiguous word "distance" entirely was the way to go.
Then someone changed it back to "distance" and that resulted in the mess you dealt with. 209.209.238.189 ( talk) 01:09, 18 August 2018 (UTC)
The third paragraph which begins "A memory card containing the names of over 1.1 million people..." seems incorrect. It should be "A data storage card containing the names of over 1.1 million people..."
In cyber technology memory is a volatile data container (does not retain data when powered off) whereas storage is a nonvolatile data container (retains data even when powered off). I presume the device is in fact a storage card sans confirmation, but very strongly believe my presumption is accurate - no even partially competent circuit or systems engineer would entrust such data to a volatile device, nor have any technical or economic reason to do so.
Please comment if you disagree or have additional perspective. Otherwise I'll make the change in about a week. Cheers! -- H Bruce Campbell ( talk) 16:52, 18 August 2018 (UTC)
Users of satellites on Earth have to deal seasonally with sun transit, when the satellite passes between the sun and the receiver, causing the satellite signal to be overwhelmed by the unmodulated but powerful output of the sun. How will Parker's signal be detected against this solar output? I am wondering if these close passes or the transmission time will occur when the probe is actually "beside" the sun, and not in front of it, that is, it is about to slip around the far side of the sun. GBC ( talk) 17:54, 8 August 2018 (UTC)
Current two dimensional table is hard to read. A simple table like below is better.―― Phoenix7777 ( talk) 04:00, 13 August 2018 (UTC)
Year | Date | Events | Distance (million km) |
Velocity (km/s) |
Orbital period (day) |
---|---|---|---|---|---|
2018 | Aug 12 | Launch | – | – | – |
Sep 28 | Venus flyby #1 | – | – | – | |
Nov 1 | Perihelion #1 | 25 | 95 | 150 | |
2019 | Mar 31 | Perihelion #2 | 25 | 95 | 150 |
Aug 28 | Perihelion #3 | 25 | 95 | 150 | |
Dec 21 | Venus flyby #2 | – | – | – | |
2020 | Jan 24 | Perihelion #4 | 20 | 109 | 130 |
Jun 2 | Perihelion #5 | 20 | 109 | 130 | |
Jul 6 | Venus flyby #3 | – | – | – | |
Sep 22 | Perihelion #6 | 14 | 129 | 112.5 |
@ Phoenix7777: I see you added JPL Horizons as a source, but it's unclear how it can be queried to generate the necessary data. Can you build a URL that would enable a reader to WP:verify the information? Otherwise, we should find another source, or explain. Also, any chance to get the speeds at Venus, and possibly speed differentials imparted by the gravity assist? — JFG talk 06:56, 17 August 2018 (UTC)
@ JFG: @ 209.209.238.189: HORIZONS Web-Interface now provides a revised data (Aug 24) from 2018-Aug-12 to 2025-Aug-31. Although the minimum time step size is 1 minute, the output length 3,709,503 exceeds 90,024 line max. So I created a url with a time step size of 1 hour.―― Phoenix7777 ( talk) 22:42, 25 August 2018 (UTC)
Regarding the Venus gravity assists, I think it would be worthwhile to add extra columns showing speed and distance relative to Venus (+ perhaps Δv imparted), and still fine to list speed and distance relative to Sun in the existing column. — JFG talk 07:29, 28 August 2018 (UTC)
I'm afraid I have to disagree with myself. I just realized that SPP is only making Venus encounters and I don't think any major maneuvers are planned. In that case, there is a conservation law which applies and the approach velocity to Venus will be essentially the same on all encounters. That wouldn't be worth giving its own column in the table. Simply stating the number in the text would be sufficient along with the range at which it was calculated (I think the Sphere of Influence is the traditional distance.) For the table, I now think it would be best to simply add a column for the closest approach distance on Venus encounters. Fcrary ( talk) 01:08, 29 August 2018 (UTC)
To the extent that the assumptions of the restricted three body problem apply, the approach speed to Venus (and the departure speed after the encounter) are conserved quantities. Those assumptions are that the spacecraft's mass is negligible compared to that of Venus and the Sun (a very good approximation), that the orbit of Venus is circular (it's 0.007) and that only the gravity of the Sun and Venus matter (rocket firings and distant perturbations from other planets cause slight variations.) It doesn't matter where along the spacecraft's orbit the encounter occurs, not does the eccentricity of the spacecraft's orbit. Fcrary ( talk) 20:20, 27 October 2018 (UTC)
That animation of the orbits is very interesting. But I wonder if there's a way to slow it down here and there, or pause it. Uporządnicki ( talk) 17:26, 24 October 2018 (UTC)
Does anyone know how to fix the aspect ratio on the trajectory animation? Circular (or near circular) orbits ought to be shown as circular. The animation looks like the x:y scale is about 2:3, not 1:1. Fcrary ( talk) 22:04, 12 August 2018 (UTC)
The page discusses the instruments without mention of the flight software itself. The Flight Software Workshop by Christopher Krupiarz ( http://flightsoftware.jhuapl.edu/files/2015/Day-1/SolarProbePlusOverviewFINAL.pptx) gives detailed information on the LEON3 flight hardware, software requirements, and functionality. It includes great information on the software architecture noting the it uses RTEMS, OSAL, and the Core Flight Executive along with the "lollipop" diagram of mission functionality attached to the cFE. It would be nice to get a section on the flight software in the page. Any thoughts on where it might go? -- JoelSherrill ( talk) 15:23, 14 August 2018 (UTC)
I've been very curious, for myself, about two aspects of this mission: the successive aphelia and the Venus flybys. I've found some good information on line about those flybys; from it, I can gather:
I've been contemplating ways of incorporating that information in the table of perihelia and other events. Whatever I've thought of will certainly add a lot to the table--at least in terms of stuff; whether it will add to it in terms of quality, usefulness and interest, I haven't decided. Thoughts, anybody? Is all/any of that of sufficient interest to warrant inclusion? One thought I had--the one that would clutter the table the least--is to add the distance of the flyby, and whatever I wind up including of the rest of the information--relegate that to notes. Uporządnicki ( talk) 18:33, 27 November 2018 (UTC)
A couple of editors (one named and one IP) have lately undertaken to go through and make a number of largely cosmetic edits to this page. One of those has been to change "au" (astronomical units) to "AU". Nobody has caught them all, so as I write this, both are to be found in this page.
Let me point out, please, that according to the Wikipedia Manual of Style, "au" is preferred.
Wikipedia:Manual_of_Style/Dates_and_numbers#Units_of_measurement
Both "au" and "AU" are allowed, insofar as we're advised NOT to go through fixing an article that uses "AU". The Manual encourages a consensus for any one article.
Uporządnicki (
talk)
15:31, 6 March 2020 (UTC)
User:Randey1970 just made an edit changing the date of Parker's most recent record for proximity to the Sun from September 27, 2020 to January 17, 2021 (the day I'm writing this). It is true that the Probe was supposed to reach its latest perihelion today. But since there was no intervening gravity assist from an encounter with Venus, that perihelion should have been exactly the same as the earlier one. As I understand the term, you set a record the first time you reach some milestone, not a subsequent one. And the source cited, dated September 25, doesn't even address the perihelion of January 17. User:Randey1970 added one of those notes that doesn't appear in the article; it says the probe beat its own record by "a mere 531 kilometers." I'd like to know where that came from. Uporządnicki ( talk) 02:49, 18 January 2021 (UTC)
I see that someone has twice made an edit to "correct" a point about the maximum speed of the probe as it relates to the speed of light. The second time, this someone carefully explained him/herself, but s/he is still in error. And unfortunately, this is not a registered User, so there's no way to get back to him or her to point out the error. Maybe "someone" will read it here.
Dear Mr./Ms. Someone, you keep changing 0.064 to 0.00064. You are correct, up to a point. The maximum speed the probe is planned to reach will indeed be 0.00064 of the speed of light. But the statement you keep "fixing" actually says 0.064% of the speed of light. Notice the "percent" sign, which I've bolded; that's the key. 0.99 of the speed of light IS 99% of the speed of light. 0.50 of the speed of light IS 50% of the speed of light. 0.01 of the speed of light IS 1% of the speed of light, and 0.001 of the speed of light IS 0.1% of the speed of light. Similarly, 0.00064 of the speed of light--the figure you've correctly arrived at--IS 0.064% of the speed of light--the figure given in the article.
Uporządnicki (
talk)
18:05, 1 April 2019 (UTC)
There is no known material in the entire world, not even from 'NASA' that can withstand the speeds & temperatures claimed here - this is ludicrous to attempt to 'pass off' as FACT today. — Preceding unsigned comment added by 160.2.51.245 ( talk) 02:57, 22 October 2021 (UTC)
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
What does it mean to be the "fastest" object when something is in space?
That is, speed relative to what? — Preceding unsigned comment added by 93.34.50.240 ( talk) 08:40, 17 August 2012 (UTC)
Please update if this is the correct link. http://spacenews.com/41380solar-probe-plus-nasas-mission-to-the-fires-of-hell-trading-atlas-5-for/
BenjaminJMeyer ( talk) 08:30, 2 January 2015 (UTC)
Hello fellow Wikipedians,
I have just modified 4 external links on Parker Solar Probe. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 16:58, 10 September 2017 (UTC)
I know relativity is needed to explain long term precession of Mercury. I'm curious if relativistic corrections are needed for a mission like that? Tom Ruen ( talk) 19:45, 22 November 2017 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Parker Solar Probe. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 18:57, 12 January 2018 (UTC)
Of what materials is the Parker Solar Probe to be constructed? MaynardClark ( talk) 17:59, 21 August 2017 (UTC)
Various different materials. I don't have to whole list. But that, as well as a description of the spacecraft and the instruments, should really be added to this page. Fcrary ( talk) 18:03, 21 August 2017 (UTC)
Can we have details on the design of SACS (Solar Array Cooling System)? What I have read so far is that it uses one gallon of water and there's a pump (not heat pipes). But how is the water kept from freezing when the spacecraft is far away from the Sun? Is it stored in a heated reservoir and the system is bled (possibly purging some filler gas?) once the probe gets close enough to the Sun for water not to freeze? Or perhaps it's naturally kept above freezing point at all times as it circulates in the exposed solar panels? And how is thermal expansion (of water) compensated for?
There is currently a sidebar diagram showing Voyager 2 info, with the following caption:
Plot of Voyager 2's heliocentric velocity against its distance from the Sun, illustrating the use of gravity assist to accelerate the spacecraft by Jupiter, Saturn and Uranus.[23] Using the same technique but with Venus, Parker Solar Probe will decelerate to lower its orbit.
This isn't really useful in this article; it feels like someone threw it in because it's available and somewhat related. Plus, Section 2 is really unbalanced at this point, with the sidebar being far taller than the body text.
Would it be appropriate to remove the diagram? -- Dan Griscom ( talk) 13:04, 11 August 2018 (UTC)
How much did that probe cost? — Preceding unsigned comment added by 78.49.247.38 ( talk) 09:19, 15 August 2018 (UTC)
@ Mfb: Re: your edit, FYI that was caused by a change in column heading. It was originally perihelion distance, and was accurate for the launch orbit. (But of course, the spacecraft was nowhere near perihelion; it launched from 1.0 AU, not 0.278.) I changed the column heading to "perihelion" to help untangle the frequent confusion in various sources between distance-from-Sun-center and altitude-above-Sun-surface. I thought using "perihelion" for the former and "altitude" for the latter and avoiding the ambiguous word "distance" entirely was the way to go.
Then someone changed it back to "distance" and that resulted in the mess you dealt with. 209.209.238.189 ( talk) 01:09, 18 August 2018 (UTC)
The third paragraph which begins "A memory card containing the names of over 1.1 million people..." seems incorrect. It should be "A data storage card containing the names of over 1.1 million people..."
In cyber technology memory is a volatile data container (does not retain data when powered off) whereas storage is a nonvolatile data container (retains data even when powered off). I presume the device is in fact a storage card sans confirmation, but very strongly believe my presumption is accurate - no even partially competent circuit or systems engineer would entrust such data to a volatile device, nor have any technical or economic reason to do so.
Please comment if you disagree or have additional perspective. Otherwise I'll make the change in about a week. Cheers! -- H Bruce Campbell ( talk) 16:52, 18 August 2018 (UTC)
Users of satellites on Earth have to deal seasonally with sun transit, when the satellite passes between the sun and the receiver, causing the satellite signal to be overwhelmed by the unmodulated but powerful output of the sun. How will Parker's signal be detected against this solar output? I am wondering if these close passes or the transmission time will occur when the probe is actually "beside" the sun, and not in front of it, that is, it is about to slip around the far side of the sun. GBC ( talk) 17:54, 8 August 2018 (UTC)
Current two dimensional table is hard to read. A simple table like below is better.―― Phoenix7777 ( talk) 04:00, 13 August 2018 (UTC)
Year | Date | Events | Distance (million km) |
Velocity (km/s) |
Orbital period (day) |
---|---|---|---|---|---|
2018 | Aug 12 | Launch | – | – | – |
Sep 28 | Venus flyby #1 | – | – | – | |
Nov 1 | Perihelion #1 | 25 | 95 | 150 | |
2019 | Mar 31 | Perihelion #2 | 25 | 95 | 150 |
Aug 28 | Perihelion #3 | 25 | 95 | 150 | |
Dec 21 | Venus flyby #2 | – | – | – | |
2020 | Jan 24 | Perihelion #4 | 20 | 109 | 130 |
Jun 2 | Perihelion #5 | 20 | 109 | 130 | |
Jul 6 | Venus flyby #3 | – | – | – | |
Sep 22 | Perihelion #6 | 14 | 129 | 112.5 |
@ Phoenix7777: I see you added JPL Horizons as a source, but it's unclear how it can be queried to generate the necessary data. Can you build a URL that would enable a reader to WP:verify the information? Otherwise, we should find another source, or explain. Also, any chance to get the speeds at Venus, and possibly speed differentials imparted by the gravity assist? — JFG talk 06:56, 17 August 2018 (UTC)
@ JFG: @ 209.209.238.189: HORIZONS Web-Interface now provides a revised data (Aug 24) from 2018-Aug-12 to 2025-Aug-31. Although the minimum time step size is 1 minute, the output length 3,709,503 exceeds 90,024 line max. So I created a url with a time step size of 1 hour.―― Phoenix7777 ( talk) 22:42, 25 August 2018 (UTC)
Regarding the Venus gravity assists, I think it would be worthwhile to add extra columns showing speed and distance relative to Venus (+ perhaps Δv imparted), and still fine to list speed and distance relative to Sun in the existing column. — JFG talk 07:29, 28 August 2018 (UTC)
I'm afraid I have to disagree with myself. I just realized that SPP is only making Venus encounters and I don't think any major maneuvers are planned. In that case, there is a conservation law which applies and the approach velocity to Venus will be essentially the same on all encounters. That wouldn't be worth giving its own column in the table. Simply stating the number in the text would be sufficient along with the range at which it was calculated (I think the Sphere of Influence is the traditional distance.) For the table, I now think it would be best to simply add a column for the closest approach distance on Venus encounters. Fcrary ( talk) 01:08, 29 August 2018 (UTC)
To the extent that the assumptions of the restricted three body problem apply, the approach speed to Venus (and the departure speed after the encounter) are conserved quantities. Those assumptions are that the spacecraft's mass is negligible compared to that of Venus and the Sun (a very good approximation), that the orbit of Venus is circular (it's 0.007) and that only the gravity of the Sun and Venus matter (rocket firings and distant perturbations from other planets cause slight variations.) It doesn't matter where along the spacecraft's orbit the encounter occurs, not does the eccentricity of the spacecraft's orbit. Fcrary ( talk) 20:20, 27 October 2018 (UTC)
That animation of the orbits is very interesting. But I wonder if there's a way to slow it down here and there, or pause it. Uporządnicki ( talk) 17:26, 24 October 2018 (UTC)
Does anyone know how to fix the aspect ratio on the trajectory animation? Circular (or near circular) orbits ought to be shown as circular. The animation looks like the x:y scale is about 2:3, not 1:1. Fcrary ( talk) 22:04, 12 August 2018 (UTC)
The page discusses the instruments without mention of the flight software itself. The Flight Software Workshop by Christopher Krupiarz ( http://flightsoftware.jhuapl.edu/files/2015/Day-1/SolarProbePlusOverviewFINAL.pptx) gives detailed information on the LEON3 flight hardware, software requirements, and functionality. It includes great information on the software architecture noting the it uses RTEMS, OSAL, and the Core Flight Executive along with the "lollipop" diagram of mission functionality attached to the cFE. It would be nice to get a section on the flight software in the page. Any thoughts on where it might go? -- JoelSherrill ( talk) 15:23, 14 August 2018 (UTC)
I've been very curious, for myself, about two aspects of this mission: the successive aphelia and the Venus flybys. I've found some good information on line about those flybys; from it, I can gather:
I've been contemplating ways of incorporating that information in the table of perihelia and other events. Whatever I've thought of will certainly add a lot to the table--at least in terms of stuff; whether it will add to it in terms of quality, usefulness and interest, I haven't decided. Thoughts, anybody? Is all/any of that of sufficient interest to warrant inclusion? One thought I had--the one that would clutter the table the least--is to add the distance of the flyby, and whatever I wind up including of the rest of the information--relegate that to notes. Uporządnicki ( talk) 18:33, 27 November 2018 (UTC)
A couple of editors (one named and one IP) have lately undertaken to go through and make a number of largely cosmetic edits to this page. One of those has been to change "au" (astronomical units) to "AU". Nobody has caught them all, so as I write this, both are to be found in this page.
Let me point out, please, that according to the Wikipedia Manual of Style, "au" is preferred.
Wikipedia:Manual_of_Style/Dates_and_numbers#Units_of_measurement
Both "au" and "AU" are allowed, insofar as we're advised NOT to go through fixing an article that uses "AU". The Manual encourages a consensus for any one article.
Uporządnicki (
talk)
15:31, 6 March 2020 (UTC)
User:Randey1970 just made an edit changing the date of Parker's most recent record for proximity to the Sun from September 27, 2020 to January 17, 2021 (the day I'm writing this). It is true that the Probe was supposed to reach its latest perihelion today. But since there was no intervening gravity assist from an encounter with Venus, that perihelion should have been exactly the same as the earlier one. As I understand the term, you set a record the first time you reach some milestone, not a subsequent one. And the source cited, dated September 25, doesn't even address the perihelion of January 17. User:Randey1970 added one of those notes that doesn't appear in the article; it says the probe beat its own record by "a mere 531 kilometers." I'd like to know where that came from. Uporządnicki ( talk) 02:49, 18 January 2021 (UTC)
I see that someone has twice made an edit to "correct" a point about the maximum speed of the probe as it relates to the speed of light. The second time, this someone carefully explained him/herself, but s/he is still in error. And unfortunately, this is not a registered User, so there's no way to get back to him or her to point out the error. Maybe "someone" will read it here.
Dear Mr./Ms. Someone, you keep changing 0.064 to 0.00064. You are correct, up to a point. The maximum speed the probe is planned to reach will indeed be 0.00064 of the speed of light. But the statement you keep "fixing" actually says 0.064% of the speed of light. Notice the "percent" sign, which I've bolded; that's the key. 0.99 of the speed of light IS 99% of the speed of light. 0.50 of the speed of light IS 50% of the speed of light. 0.01 of the speed of light IS 1% of the speed of light, and 0.001 of the speed of light IS 0.1% of the speed of light. Similarly, 0.00064 of the speed of light--the figure you've correctly arrived at--IS 0.064% of the speed of light--the figure given in the article.
Uporządnicki (
talk)
18:05, 1 April 2019 (UTC)
There is no known material in the entire world, not even from 'NASA' that can withstand the speeds & temperatures claimed here - this is ludicrous to attempt to 'pass off' as FACT today. — Preceding unsigned comment added by 160.2.51.245 ( talk) 02:57, 22 October 2021 (UTC)