RE: Space Track API - Problems

From: Ciprian Sufitchi (
Date: Sat Sep 01 2012 - 05:03:12 UTC

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    The web site is now getting TLEs from the new API, apparently
    everything is ok.
    -----Original Message-----
    [] On Behalf Of
    Ciprian Sufitchi
    Sent: Saturday, September 01, 2012 12:20 AM
    To: 'satelliet lijst (SeeSat)'
    Subject: RE: Space Track API - Problems
    The space-track development team has added a new class (tle_latest) to help
    us retrieve the whole TLE catalog. 
    "This will return the most recent TLE for each object in the catalog  
    under nominal system load in about 30 seconds.   You can get up to 5  
    TLEs for each object by varying the ORDINAL between 1-5 or get all 5 by
    omitting ORDINAL altogether."
    This query would return all TLEs for all objects (1 TLE per NORAD_CAT_ID):
    It returns data very fast. However space-track development team requested
    not to abuse the usage of the new class:
    "Please understand that you share this database with thousands of others in
    the space community and we request that you do not craft scripts that will
    repeatedly hit this URL in short time spans.  Given the pace of updates to
    the database, it is reasonable to limit your queries to only once every 4
    hours. Also, please select a random minute for your script to run so all
    queries don't converge at the top or the bottom of the hour."
    Thank you Space-Track!
    -----Original Message-----
    [] On Behalf Of Ryan
    Sent: Friday, August 31, 2012 11:49 PM
    To: satelliet lijst (SeeSat)
    Subject: Re: Space Track API - Problems
    I agree with you that no one needs to download the entire catalog every few
    hours; however, they might need to download the changes that often.  The
    missing point is that there are use cases beyond visual satellite
    observations.  I can use fairly ancient TLEs to catch a satellite with
    binoculars, but that's not the case when I am at my day job.  Satellite
    operators need more timely space situational awareness data than what is
    required to observe a satellite.  I often need to know if another operator's
    satellite has been maneuvering recently or if an object has displayed recent
    out-gassing events.  These data are of course supplemental to more accurate
    information available on space-track to authorized users, but they are
    nevertheless useful.  For my job, I download the alldata files once a day
    and the am/pm last-update files twice a day (at home, I only download them
    every few weeks).  The new interface promises to be more useful for my job
     that I could, without wasting anyone's bandwidth, query the catalog for
    changes a little more often.
     From: Marco Langbroek <>
    To:; satelliet lijst (SeeSat) <> 
    Sent: Friday, August 31, 2012 6:23 AM
    Subject: Re: Space Track API - Problems
    Op 31-8-2012 10:21, Ciprian Sufitchi schreef:
    >  Or leave the API the way it is now, but keep generating the TLE
    > bulk file once every 6 hours or so.
    Maybe I am missing something here.
    I don't see at all why you'd need such frequent full database updates.
    One full catalogue download a day is MORE than adequate to generate adequate
    predictions or check sightings.
    In case of following objects near decay, or newly launched objects, the
    of these can better be retrieved short before the intended observation via
    option to retrieve one or a few catalogue number elements.
    I download the bulk tle files 1 or 2 times a week at best, and that is more
    - Marco
    Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.
    Cospar 4353 (Leiden):   52.15412 N, 4.49081 E (WGS84), +0 m ASL
    Cospar 4354 (De Wilck): 52.11685 N, 4.56016 E (WGS84), -2 m ASL
    Station (b)log:
    Twitter: @Marco_Langbroek
    Seesat-l mailing list
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