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Using skyfield I get the error :

OSError: cannot get ftp://cddis.nasa.gov/products/iers/deltat.data because <urlopen error ftp error: TimeoutError(10060, 'Ein Verbindungsversuch ist fehlgeschlagen, da die Gegenstelle nach einer bestimmten Zeitspanne nicht richtig reagiert hat, oder die hergestellte Verbindung war fehlerhaft, da der verbundene Host nicht reagiert hat', None, 10060, None)>

I found this message:

US Government security requirements no longer permit CDDIS to offer data via traditional unencrypted anonumous ftp; this service was discontinued on October 31, 2020. All data are still available, however access must be via HTTPS or ftp-ssl.

So how to use HTTPS instead of FTP?

Should I install PycURL – A Python Interface To The cURL library?

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    $\begingroup$ I’m voting to close this because it's a coding question, not space exploration. Stack Exchange itself would be a better place to ask this. $\endgroup$ – GdD Nov 17 '20 at 17:51
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    $\begingroup$ Surely this is a question about how to use an app, not how to code it. $\endgroup$ – Organic Marble Nov 17 '20 at 18:09
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    $\begingroup$ @OrganicMarble The issue seems to be that Skyfield uses an internal FTP connection to CDDIS to update it's internal Earth orientation data. That update method is no longer working due to US government mandated changes to improve server security (I suspect this is also what has lead to the extended downtime of the USNO servers and rewrite of several pieces of code that used to hit USNO for the info, to get the needed data from elsewhere) $\endgroup$ – astrosnapper Nov 17 '20 at 18:18
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    $\begingroup$ Agree that the question could have been borderline for this site but it seemed a simple fix and wanted to spare the OP from having to go to Stack Exchange - there be dragons... ;-) $\endgroup$ – astrosnapper Nov 17 '20 at 18:22
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    $\begingroup$ @JCRM For issues such as "I'm doing it like the documentation says but now I'm getting this strange error" Skyfield's Github Issues might be the first point of call. But this particular issue involving NASA servers it's fine here and in fact kind of interesting! 80 views in 21 hours, 9 total up votes... it's benefits the site to ask here. $\endgroup$ – uhoh Nov 18 '20 at 15:30
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Looks like this was an issue that was fixed and closed recently so try updating your copy of Skyfield to at least version 1.31.

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    $\begingroup$ Yes, upgrading skyfield to 1.31 should help. I will try. $\endgroup$ – Uwe Nov 17 '20 at 18:16
  • $\begingroup$ After upgrading to 1.31 I had to add the line: conf.iers_auto_url = 'toshi.nofs.navy.mil/ser7/finals2000A.all' But this was not all, I had to download the file 'finals2000A.all' into the directory ...Documents/fishing/SkyData\\finals2000A.all' manually $\endgroup$ – Uwe Nov 18 '20 at 9:24
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    $\begingroup$ This seems to be a bug in skyfield and I suggest you file an issue there. According to the docs you should be able to do a from skyfield.api import load ; load.timescale(builtin=False) but this fails for me also. The code in iokit.py has the URL for the finals2000A.all but just tries to open a local copy and doesn't fetch it if missing. $\endgroup$ – astrosnapper Nov 18 '20 at 17:21
  • $\begingroup$ Yes, I think so, it seems to be a bug and I will file an issue. But I have to register first. I agree, if the local file is missing, it should be fetched anyway. $\endgroup$ – Uwe Nov 18 '20 at 17:59
  • $\begingroup$ I filed an issue and got help. I upgraded to 1.33 as recommended and renamed the local file finals2000A.all to another name. The file was loaded again without problems into the directory ..\Documents\fishing\SkyData Problem solved in version 1.33 $\endgroup$ – Uwe Nov 18 '20 at 21:57

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