https://www.spacedaily.com/reports/SpaceX_Dragon_Capsule_to_Make_First_of_Its_Kind_Science_Splashdown_999.html Regards John On 09/01/2021 10:09, Bob Christy wrote: > Sleep is a wonderful thing! > > There is another explanation for the dispersed areas, with clues in the navigation warning for the Crew Dragon return in 2020. Thanks, John, for providing it. > > The areas represent a decision that can be made relatively last minute. > > The orbital period in the post-undocking phase of the mission can be used to 'aim' Dragon at the chosen zone. > > The areas allow a range of Ascending Node longitudes. > > The associated ground tracks avoid overflights of major urban areas, like Orlando and Jacksonville, in the closing stages to cover for debris-shedding or the vehicle falling short of the target. > > Bob Christy > >> On 8 Jan 2021, at 22:13, Bob Christy <bob_at_zarya.info> wrote: >> >> I've taken a closer look at the areas in the navigation warning. >> >> They represent the aim points for the Dragon CRS-21 splashdown on successive (almost) days. >> >> Undocking is set for Jan 11 which after Dragon will manoeuvre down to an orbit with a period of about 88.8 minutes. >> >> If re-entry has to be waved off for any reason on Jan 12 then opportunities are available over the following few days. >> >> Splash points are: >> Jan 12 - Zone A >> Jan 13 - no attempt, final few km of ground track would pass directly over Orlando. >> Jan 14 - Zone B >> Jan 15 - Zone C >> Jan 16 - Zone D >> >> Zones A, B and C are in the Atlantic Ocean. >> >> Zone D is to the west of Florida in the Gulf of Mexico. The reason may be because an Atlantic splashdown would require the track to pass directly over Jacksonville in its final moments. >> >> The navigation warning omits the times for Jan 16. >> >> Bob Christy >> >> >>> On 8 Jan 2021, at 11:56, satcom ops via Seesat-l <seesat-l_at_satobs.org> wrote: >>> >>> https://postimg.cc/jwbmmp08 >>> >>> 080821Z JAN 21 >>> NAVAREA IV 26/21(11). >>> WESTERN NORTH ATLANTIC. >>> GULF OF MEXICO. >>> FLORIDA. >>> 1. HAZARDOUS OPERATIONS, SPACE DEBRIS >>> IN AREAS BOUND BY: >>> A. 120150Z TO 120220Z JAN, ALTERNATE >>> 140100Z TO 140130Z AND >>> 150035Z TO 150105Z JAN >>> 29-20-45N 080-13-48W, 28-50-56N 079-43-04W, >>> 28-21-14N 080-13-48W, 28-50-56N 080-44-31W. >>> B. 120155Z TO 120225Z JAN, ALTERNATE >>> 140105Z TO 140135Z AND >>> 150045Z TO 150115Z JAN >>> 30-17-45N 080-35-59W, 29-47-56N 080-04-58W, >>> 29-18-14N 080-35-59W, 29-47-56N 081-07-01W. >>> C. 120200Z TO 120230Z JAN, ALTERNATE >>> 140110Z TO 140140Z AND >>> 150045Z TO 150115Z JAN >>> 31-24-45N 080-15-00W, 30-54-56N 079-43-36W, >>> 30-25-14N 080-15-00W, 30-54-56N 080-46-23W. >>> D. 120200Z TO 120230Z JAN, ALTERNATE >>> 140110Z TO 140140Z AND >>> 150050Z TO 150120Z JAN >>> 28-59-45N 083-45-00W, 28-29-56N 083-14-20W, >>> 28-00-14N 083-45-00W, 28-29-56N 084-15-39W. >>> 2. CANCEL THIS MSG 150220Z JAN 21. >>> -- >>> Regards >>> >>> John -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Mon Jan 11 2021 - 03:13:31 UTC
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