Current TLEs for Low Earth Orbit communications satellites - Starlink Etc


John Murrell
 

One of the outputs of the SATCON conference was a commitment by the LEO communication satellite operators to make the TLEs for their satellites available as the NORAD TLE's for these satellites are unreliable as it takes time for NORAD to track them, calculate their orbits and then publish them. As the orbits are continuously changing for several weeks after launch as they use the ion thrusters to reach their final orbits positions / times from the NORAD elements are wrong. To allow astronomers to better predict when LEO satellites would be crossing their telescope field of view the LEO constellation operators agreed to publish up to date TLE elements from their operation centres.  This also applies to satellites being de-orbited and to some extent if they have to maneuver when in operational orbit.

These up to date 'live' TLEs are now available on Celestrak on the page at https://celestrak.com/NORAD/elements/supplemental/ .

Can CdC be modified so that these elements can be downloaded and used for satellite predictions ? One challenge is that the elements are continuously being updated so to get an accurate prediction one needs to use the latest TLE.

The current TLE only show a 'static' orbital solution and do not allow for an orbit that is changing slowly over several weeks.

John Murrell


Patrick Chevalley
 

John,

You can use this elements directly with the latest version of CdC.
No change is require in the program because this is standard TLE, only the way they are computed before to reach Celestrak change.

For example with CdC 4.3 use this steps to add the Starlink elements:
- open the menu "Setup / Update", Artificial satellites tab ( this is "Setup / Internet" in version 4.2)
- from the Celestrak web page copy the link for "Starlink TLEs": https://celestrak.com/NORAD/elements/supplemental/starlink.txt
- past the link to add to the URL list
- click OK and save the CdC configuration

Now you can get the last elements at any time using the menu Update / Artificial satellites, or using the "Download TLE" button from the Calendar.

A change I can make to the program is to add a button to quickly insert all this elements URL to the download list.

Patrick