Space Traffic Management Working Group - TASK GROUP I

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  • 1.  New members only post

    Posted 01 Jul, 2020 21:43
    Hello TG1 Members

    This is the public-facing group where we will publish material once it is suitable for public access.  I have attempted to add every member of this group to the members-only group where the work will be developed.  If you are not in the group it is because I need to have you in my contacts in order to add you. I am learning this system just as you are.  But if you did not get a post from the members-only group, it is because you have not yet accepted my contact request. Please do so, and I will add you.  

    Sincerely, 
    Ruth Stilwell
    TG1 lead

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    Ruth Stilwell
    Ft Lauderdale FL
    (954)610-5540
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  • 2.  RE: New members only post

    Posted 02 Jul, 2020 07:50
      |   view attached

    Ruth et al,

     

    Happy 4th – here is a little reading for the long weekend. Mark Skinner (Aerospace Corp and IAASS) asked me to put something together about "my definition" of STM since we really cannot solve this problem unless we are all talking about the same "thing."

     

    Darren

     

    Dr. Darren McKnight

    Technical Director, Centauri

    darren.mcknight@centauricorp.com

    15020 Conference Center Drive

    Chantilly, VA  20151

    Phone:   703-674-3137

    Mobile:   703-402-4484

    www.centauricorp.com

     

     

    "Since all models are wrong, the scientist cannot obtain a 'correct' one by 'excessive elaboration' and the scientist must be alert to what is importantly wrong. It is inappropriate to be concerned about mice when there are tigers abroad."

     

          George Box, "Science and Statistics," Journal of the American Statistical Association, 1976

     




    Attachment(s)



  • 3.  RE: New members only post

    Posted 02 Jul, 2020 10:16
    Darren, I just had time for a quick overview of your slides and yes, that is exactly what we need to do.  Take things down to the component parts, work on the pieces and bring it together as a system!!!  

    Can we use your slides to start to put together the framework for our roadmap product?  Are there any restrictions on use?  

    Ruth


    Dr. Ruth Stilwell

    ruth.stilwell@gmail.com

    +1-954-610-5540







  • 4.  RE: New members only post

    Posted 02 Jul, 2020 10:57

    Ruth,

     

    THANKS!

     

    No restrictions other than they are really more engineering notes than a polished paper... so easier for others to mark up and improve!!!

     

    Have a great 4th!

     

    Darren

     






  • 5.  RE: New members only post

    Posted 02 Jul, 2020 12:58
    Slides 4 and 7 describe ADR and JCA. It would be useful, especially for those of us planning ADR/JCA, if greater specificity could be provided regarding the objects subject to each form of remediation. For example, several published or planned studies of the most statistically concerning objects for ADR focus on the same 50-100 objects which are already identified by SATCAT number. JCA focuses on close conjunctions over shorter time frames, and also involves a similar (and to some extent the same) group of objects. I suggest adding an additional brown check mark at the end of slide 8 to indicate that "50-100 specific objects have been identified for ADR and JCA". One of the reasons ADR has not yet taken wing in the countries involved is, in my view, because, in the eyes of policy makers, it rests on statistical probabilities, which are not always effective motivators for action.

    Chuck Dickey
    +1-832-992-1492

    TCTB, LLC
    Houston, TX 77259



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    Chuck Dickey
    TCTB, LLC
    Houston TX
    832-992-1492
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  • 6.  RE: New members only post

    Posted 02 Jul, 2020 14:14

    Good question – the answer is not simple. First, neither system exists operationally though ADR systems are getting very close. The first criteria for use would be if a system (i.e., ADR vs JCA) actually exists to use. When there is only one, the debate is purely academic.

     

    After that clearly, ADR permanently eliminates the collision risk while JCA only temporarily reduces the orbital collision risk. However, JCA will most likely be much less expensive than ADR but the JCA cost will have to fold in the potential "false alarm" problem (i.e., one might "nudge" an object when in reality the two objects would have missed so the true cost for remediation might be a multiple [2 or 3?] of the cost of a JCA mission). However, for the very large objects over 1,000 kg (especially 9,000 kg SL-16 RBs), removing their collision risk does not eliminate risk; it just moves the risk to aviation and ground impacts while JCA does not deflect the risk to another domain.

     

    Next, ADR remediates statistical risk of collision (i.e., long-term over many years and many close approaches) while JCA remediates a deterministic collision risk (i.e., reduce the risk from a single encounter). These are both very different in magnitude and uncertainty plus potentially apply different legal and regulatory perspectives. For example, you would never have ADR operate on an operational satellite, however, JCA might be a viable means for an operator of a satellite that did not have collision avoidance capability. This makes JCA, in essence, a space traffic management (STM) action and, possibly even, a constellation resiliency activity.

     

    Dr. Darren McKnight

    Technical Director, Centauri

    darren.mcknight@centauricorp.com

    15020 Conference Center Drive

    Chantilly, VA  20151

    Phone:   703-674-3137

    Mobile:   703-402-4484

    www.centauricorp.com

     

     

    "Since all models are wrong, the scientist cannot obtain a 'correct' one by 'excessive elaboration' and the scientist must be alert to what is importantly wrong. It is inappropriate to be concerned about mice when there are tigers abroad."

     

          George Box, "Science and Statistics," Journal of the American Statistical Association, 1976