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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier">Mario, Marc:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier">Attached is a slide that is normally in the Working Group reports to Area Directors. The Nav WG discussed starting these new projects during our Spring Meetings (see p.4 of our Spring 2021
report), but I didn't have time to prepare the slide with the requisite planning.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier">I must confess I've forgotten the units in the columns related to Total, Editor, and Prototypes; I've used estimated project duration in months as an estimate.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier">Here are rationales for the 2 documents:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier">500.2-G-3: The previous issue 500.2-G-2 has become a bit out of date. This volume is intended to provide an overview of the currently published and envisioned CCSDS Navigation Data Messages. An
update will show that the Re-Entry Data Messages has now been published, update some material for the Tracking Data Message V.2, and briefly describe new material being added to the Orbit Data Messages and Attitude Data Messages. A short preview of a future
"modular message" envisioned by the Working Group will also be provided.<o:p></o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier">505.0-B-3: The previous issue 505.0-B-2 removed XML material related to the Tracking Data Message (TDM) because it is now incorporated directly into the TDM Version 2. This new version of the
XML specification document will remove XML material related to the Orbit Data Messages (ODM) and Attitude Data Messages (ADM) because that material is currently being incorporated directly into the ODM and ADM respectively. The timing of the 505 update will
necessarily be tied to the progress of the ODM and ADM updates currently in progress, so the publication schedule will depend on the progress of those 2 documents. Note that when 505.0-B-2 was proposed, a waiver was granted to not require prototypes because
material was only being removed, not added. However, we did do a single prototype for 505.0-B-2 due to having added a set of schemas for elementFormDefault='qualified' (request of Service Management). In this 505.0-B-3, it is envisioned that technical material
will only be removed; in this case, the original plan to not require prototypes should still be viable. Accordingly, I have put asterisks in the prototype columns for this document update.<o:p></o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier">Please advise your thoughts...<o:p></o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier"><o:p> </o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier">Thanks!<o:p></o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:Courier">David<o:p></o:p></span></p>
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