Space Track TLE Retriever
Update History

  • Workarounds
    • If you experience ANY problems with the program, please take the following steps:
      1. Open TLE Retriever.
      2. Check Enable debug logging. You will be asked to restart the application (click Yes).
      3. Run through whatever steps lead up to the problem.
      4. Select Help, Send Debug Log from the pull-down menu. The log file directory will open and your mail application will launch.
      5. Attach the appropriate log file (each has a separate date/time), include a description of the problem, and send it to me for resolution. Thanks!
    • For Palm users: Since TLE Retriever 3 does not include an option to generate Palm data files (due to time limitations on my part), you may wish to check out Big Fat Tail Productions, which contains Palm versions of several TLE data sets. More importantly, they provide a Windows utility, tle2pdb, along with source code in C and Perl.
  • Future Features
    • While most users of CelesTrak seem to use Microsoft Windows, not all do. I expect that once we have rung out any issues with the Windows version of this program that I will begin developing a Java-based application which will also run on Macintosh, Unix, and Linux platforms. For those wishing to try a Perl implementation, please see Tom Wyant's contribution at
  • Version (2019 Jul 24)
    • This update is required to support the removal of TLS 1.0/1.1 used on Space Track. To support TLS 1.2, we are following Microsoft's best practices and upgrading TLE Retriever to use .NET 4.7.1. This change may require installing the Microsoft .NET Framework 4.7.1 Runtime. TLE Retriever continues to be a 32-bit application to support as many versions of Microsoft Windows, as possible. Even with that, this change means TLE Retriever will no longer work on Windows XP or Vista and Windows 7 must be upgraded to SP1 (see .NET Framework System Requirements).
    • Current users will need to replace all files in their current location, since the .exe and .dlls are all new and the .config file contains information for the change to .NET 4.7.1. If you have customized your .config file, you may need to carefully modify the new one to match it. Note that the CelesTrak.dat file has also been updated to add new TLE groups on CelesTrak. Be sure to review settings when first running the new version, make any needed changes (e.g., reenter credentials), and save your changes.
    • While I had hoped to make some major revisions to TLE Retriever with the next release, other priorities have prevented that at this time, so there are no changes in functionality with this version. I am, however, exploring options for a cross-platform solution for the next release.
  • Version (2018 Sep 08)
    • This update is required to support a change in TLS ciphers being used in Space Track 3.0. Our testing revealed that the ciphers supported in Version were no longer supported, preventing TLE Retriever from securing an HTTPS connection.
    • There is still a possibility that some users may experience problems logging in if their passwords do not conform with the instructions on the Space Track Change Password page (follow the link after first logging in). If your password does not conform with their instructions, we recommend changing your password to one that does, to prevent possible authentication problems in TLE Retriever.
    • Current TLE Retriever users can update by simply replacing the TLERetriever3.exe and ChilkatDotNet2.dll in their current installation with the ones from the installation file. It is also recommended that you update CelesTrak.dat. You will, however, still need to re-enter your Space Track credentials and save your configuration on first use.
    • There are no changes in functionality in this version.
  • Version (2014 Dec 18)
    • Added a configuration item to specify which site to check for Internet connectivity. The new setting is connectedURL. Previously, was checked, since it is a high-availability site. But this setting appears to cause configuration issues for sites with tight firewall restrictions. Now you can specify a URL which does not violate these constraints. An obvious alternative would be to check, but if Space Track is down, this check would suggest the problem was due to no Internet connectivity (a separate issue). The default setting is
  • Version (2014 Dec 18)
    • Added configuration items to allow spawning a process other than post.vbs at end of the run. There are now spawnProcessName and spawnParameters settings to specify the application to be run and any command-line options. If no path is given for the application, the application is assumed to exist in the TLE Retriever directory. The default setting is to look for post.vbs with no parameters. Please be sure to carefully test any changes to these settings.
  • Version (2014 Apr 09)
    • Fixed Space Track login (under Web Sites).
  • Version (2013 Jul 10)
    • Added code to ensure that satellite names are 24 characters or less, after JSpOC added one to the SSR with 25 characters.
  • Version (2013 Mar 07)
    • Fixed minor issue with leading zeros on satellite names for three-line Space Track data being written to CelesTrak master TLE catalog.
  • Version (2013 Mar 06)
    • Fixed issue where CelesTrak.dat file age actually showed time since creation.
    • Removed auto-update of CelesTrak.dat file since that overwrote current CelesTrak settings. An ability to reset the file will be provided in a future version. Until then, you can remove the CelesTrak.dat file at any time and it will be recreated, but the CelesTrak settings will need to be reconfigured and saved.
  • Version (2013 Feb 25)
    • New version to support using Space Track's new web services API.
  • Changes from Version 2
    • Space Track bulk downloads are done using user-configurable queries. A default set is provided, but you can create your own, too. Automatically downloads from CelesTrak, if you get too creative (just delete the old SpaceTrack.dat)!
    • The CelesTrak queries are built directly from the Current Data page. That means new data files added to that page will automatically show up in your options.
    • Technically, there is no longer an SSR available from Space Track, so the data format in this file is a pipe-delimited text file for easier processing.
    • Processing no longer needs to wait for the release of the bulk data files, so TLE Retriever can be run at other times during the day, hopefully reducing congestion on the Space Track site.

  • Version (2011 Apr 28)
    • Investigated issue regarding not being able to log into Space Track. This may be the result of using reserved characters (as defined in RFC 1738) in the Space Track credentials. At this point, I am unable to work around this issue because Space Track is not handling escaped characters properly. If you are having this problem, please contact me ASAP.
    • Fixed bug for Auto Download which resulted in update interval not being set correctly.
  • Version (2011 Apr 19)
    • Fixed interval bug which prevented Auto Download from working properly on startup.
  • Version (2011 Apr 18)
    • Fixed bug which prevented Auto Download from working properly.
    • Added option to reset screen position and size from System Tray. If application is off screen, minimize it to the System Tray, right-click the icon, and select "Reset Screen Position."
  • Version [Beta] (2011 Mar 25)
    • Fixed bug which prevented three-line TLE data from passing validation when running Process Data.
    • Added shortcut for Help (F1) and hotkeys for pull-down menu options.
    • Added additional text to post.vbs sample to explain how to get rid of the pop-up after running Process Data.
  • Version [Beta] (2011 Mar 24)
    • Changed main form to allow resizing to support users using different font sizes.
    • Fixed cosmetic issue with the appearance of the About tab on Windows Server 2008.
  • Changes from Version 1
    • May no longer support Windows versions prior to Windows XP Pro and Windows Server 2003. I no longer have any way to test these operating systems.
    • No Palm support.
    • Proxy support is handled via Windows registry default settings.
    • Auto update command line option is now "-auto" (not "-update").

  • Version 1.5.8 (2007 Oct 15)
    • Added a key in the .ini file to allow users to bypass checking CelesTrak for critical updates. This will at least allow downloading data from Space Track if Internet connectivity issues are preventing a connection to CelesTrak. While there haven't been any changes to Space Track requiring a critical update for some time, users are cautioned to disable this check only as a last resort.
  • Version 1.5.7 (2006 Mar 28)
    • Added an option to disable the error message produced when Internet connectivity is unavailable. This option will allow uninterrupted unattended operation in the event of a temporary loss of Internet connectivity.
    • Added list of WAAS, EGNOS, and MSAS satellites (the Satellite-Based Augmentation System) under Navigation Satellites.
  • Version 1.5.6 (2006 Jan 24)
    • Added list of Galileo satellites under Navigation Satellites.
  • Version 1.5.5 (2005 Jun 03)
    • Added error check to prevent seek past end of file if objects are added on CelesTrak or in user-defined data sets before they appear in the Space Track data. This change supports enhanced automated processing on CelesTrak to speed the addition of newly launched objects.
  • Version 1.5.0 (2005 Mar 23)
    • Changed the proxy configuration interface to simplify it and make it more reliable.
  • Version 1.4.2 (2005 Mar 17)
    • Changed default Internet timeout value from 15 seconds to 60 seconds to help some users avoid getting the Socket capture aborted error message. This value is also stored in the .ini file, if you feel the need to change it further.
    • Added the ability to turn off automatic checking for a proxy server. Some users appear to be having a problem because their Windows registry is set to require a proxy server but is not configured properly. Now, you can either manually turn off proxy checking or manually configure the program to use settings other than those listed in the Windows registry (see Workarounds above).
  • Version 1.4.1 (2005 Mar 11)
    • Fixed problem with generating Palm .pdb files with more than 255 TLEs.
  • Version 1.4.0 (2005 Mar 10)
    • Added a feature to check CelesTrak for critical updates before attempting to perform any operations. If a critical update is required, the program will notify you and then open the TLE Retriever web page in your browser. This capability should prevent users from wasting time unnecessarily trouble-shooting problems, such as the one caused by Space Track that led to the release of Version 1.3.11.
    • Improved timeout checking when attempting to log into Space Track or download files. Some users were reporting that certain conditions caused their program to hang when performing web access.
    • Added ability to redownload corrupted files. This problem typically occurs when attempting to access a corrupted catalog_*.gz file. While the program reports that the file is unpacked correctly, the catalog_*.txt file is not generated and a File not found error message is produced. If this happens now, the user will be given the option to delete the corrupted file and attempt to re-download it.
    • Added the capability to generate Palm .pdb format TLE files. These files (both CelesTrak and user-defined data sets) are automatically loaded in the Palm Install Tool to be installed during the next hot sync.
  • Version 1.3.11 (2005 Mar 08)
    • Corrected problem caused when Space Track made an unannounced change to the HTTP header that is returned when a user successfully logs into the site. The header change caused the program to think that the login had failed.
  • Version 1.3.10 (2005 Mar 08)
    • Added additional option for determining HTTP proxy server.
    • Added Exit option to File menu.
    • Fixed problem with not detecting changes made to Space Track and CelesTrak data sets.
    • Added capability to save form size on exit. This will mean that users who need to resize the form only have to do so once.
  • Version 1.3.9 (2005 Mar 03)
    • Added additional flexibility in determining HTTP proxy server.
  • Version 1.3.8 (2005 Mar 02)
    • Added proxy handling features to the program.
    • Fixed bug which seemed to result from the Abbrevia gzip software when handling certain path names.
    • Added some additional debug logging to aid in problem resolution.
  • Version 1.3.6 (2005 Mar 02)
    • Added checking to ensure TLE data is available for each object in a user-defined data set. If no data is found, no data will be output to the data set. If debug logging is turned on, an entry for each object not found will be entered into the log.
    • Added timestamps for each item in the debug log.
    • Fixed bug in calling post.vbs. While the program was looking for post.vbs, it was trying to execute postprocess.vbs. I had shortened the name to support systems which don't use long filenames and missed this change.
    • Included sample VBScript (sample.vbs) to demonstrate post processing. When run, the script will pop up a box telling the user if a new catalog or alldata file has been downloaded and then open up newdata.log in Notepad (you should run Download Data first to create newdata.log). Users should be able to run the script to see how it behaves by simply double-clicking on it. Please be aware that your system will probably ask you to approve running the script for security reasons. To use the script with TLE Retriever, simply rename it to post.vbs and place it in the directory with the program. When you run Process Data, the program will execute post.vbs (if it exists) at the end of that process. Hopefully, this will help users and software developers get started developing their own scripts. For help with developing VBScripts, I highly recommend DevGuru.
  • Version 1.3.5 (2005 Mar 01)
    • Added an easier way to turn on debug logging.
    • Added additional checks for other versions of Windows (e.g., Windows 98).
    • Fixed problem with determining a satellite's common name for objects not yet listed in the SSR. Earlier versions of the program may not be able to properly generate the Last 30 Day's Launches CelesTrak data set.
    • Improved positioning of the form on the screen to avoid having the form off the screen when switching from dual-display to single-display systems.
    • Added an ability to post-process data by executing a VBScript at the end of the Process Data routine. This feature should provide users enhanced flexibility to manipulate the data in support of other applications.
  • Version 1.3.0 (2005 Feb 26)
    • Added option to generate Complete Catalog as a standard CelesTrak data set.
    • Added option to generate CelesTrak data sets with either .txt or .tle file extensions.
    • Cleaned up logic to determine whether program was ready to generate CelesTrak data sets. Previously, it was possible to activate the Process Data button without having the required data by changing the Space Track Data Format choice.
    • Added TLE Retriever version and configuration information into the debug log.
  • Version 1.2.5 (2005 Feb 25)
    • Removed the code supporting the temporary gzip workaround.
  • Version 1.2.4 (2005 Feb 25)
    • Further tightened up operation of -update command-line option to ensure it does not conflict with Auto Download.
    • Fixed minor bug when asking whether to create shortcut in Startup folder.
    • Added preliminary code to determine specific Windows version and hardware for troubleshooting purposes. Information is written into .log file when Debug On=1. Also shows in About box.
  • Version 1.2.3 (2005 Feb 24)
    • Modified the logic for running the program with the -update command-line option so that it won't complain if Auto Download is set.
  • Version 1.2.2 (2005 Feb 24)
    • The problem causing the error message "Catalog file is empty. Input file was corrupt." has now been eliminated! This problem was only occurring for users on the European continent. After extensive testing, I finally narrowed down the problem to one call. As it turns out, users having the problem use the convention of having a comma as the decimal separator for real numbers rather than the period (as used in the US, UK, and Canada). Historically, CelesTrak has performed very rigorous testing of all TLEs before releasing them. This testing included not only validating checksums but ensuring every character on each line was a valid choice AND performing range checking for all numbers. The problem resulted when the code attempted to validate a number from a TLE, such as 123.4567, when the decimal separator was a comma. In those cases, the range checking failed on all real data and the program aborted. This code has been extensively tested for use in the US and has been used billions of times to check CelesTrak's historical archives of over 76 million TLEs. The Real_Value function now checks for decimal separators other than a period and adapts accordingly.
  • Version 1.2.1 (2005 Feb 22)
    • Eliminated I/O Error 103 when using three-line data (trying to close a file not already open).
    • Added full process logging when Debug On=1. All output is saved in TLE Retriever.log. This should help users resolve problems more quickly.
    • Added an option to allow users to decide whether they want to save their Space Track account information in the .ini file. Requested for security purposes.
    • Fixed login checking to trap failed logins.
  • Version 1.2.0 (2005 Feb 21)
    • The problem with unpacking GZIP files has finally been eliminated! Thanks go to Sebastian Stoff for helping me work through the solution. Now, we have a single integrated solution. Hopefully this will resolve the issues users in Europe have been reporting.
  • Version 1.1.0 (2005 Feb 21)
    • Reduced desktop size of application to permit operation on smaller desktops.
    • Added capability to build user-defined data sets. Users may create as many data sets as desired by creating files of the form [fname].query and placing them in the My TLEs\User folder. Each .query file should contain a line for each object which consists of the NORAD Catalog Number followed immediately by the common name. If only the NORAD Catalog Number is provided, the program will use the common name found in the Space Track SSR file. Each [fname].query file will produce an [fname].txt file in the User folder.
  • Version 1.0.5 (2005 Feb 20)
    • Added version information and feedback link to main page.
    • Fixed bug which was not deleting leftover files in My TLEs folder.
  • Version 1.0.4 (2005 Feb 20)
    • Space Track has finally removed the #Start Epoch and #End Epoch lines from the beginning of all files. TLE Retriever now checks to see if these lines exist before discarding the data.
    • Workarounds have now been added to address the two known unresolved bugs.
    • A newer version of gzip.exe has been added to the distribution. It is not known whether this will help with the existing problem.
  • Version 1.0.3 (2005 Feb 18)
    • Added ability to schedule program to run once and close using -update flag on command line.
    • Added prompt before creating shortcut in Startup folder.
    • Added checking for unsuccessful directory creation.
    • Added checking to delete old data left in My TLEs folder.
    • Added check for corrupt or incomplete input catalog file.
  • Version 1.0.2 (2005 Feb 17)
    • Added query to save settings on exit if any changes were made to the form.
    • Added user feedback link under Help|About menu item.
    • Added error checking for unsuccessful data transfers and increased status reporting on the status bar.
  • Version 1.0.1 (2005 Feb 16)
    • Changed Auto Download to check for existing shortcut in Startup folder before attempting to create it.
  • Version 1.0.0 (2005 Feb 15)
    • Space Track TLE Retriever released.

TLE Data Space Data
Current GPS
Archives EOP
Documentation Space Weather
SATCAT Columns
Boxscore Software
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Dr. T.S. Kelso []
Follow CelesTrak on Twitter @TSKelso
Last updated: 2019 Jul 24 18:08:26 UTC
Accessed 21,681 times since 2000 December 16
Current system time: 2019 Sep 19 10:20:38 UTC