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USCG Notice to Mariners SpaceX Crew-1 Splashdown

Posted: Mon May 03, 2021 1:04 pm
by jimh
For the return to Earth of the SpaceX Crew Dragon spacecraft RESILIENCE early on Sunday morning, May 2, 2021, in the Gulf of Mexico, the United States Coast Guard notified mariners to keep out of a large restricted area where the the spacecraft was anticipated to splash down.

So far, the only information I can find on this is a press release announcing that Notices to Mariners were released. However, I cannot find any Notice to Mariners on-line at the USCG or elsewhere that actually contain the notice.

Re: USCG Notice to Mariners SpaceX Crew-1 Splashdown

Posted: Tue May 04, 2021 11:00 am
by jimh
I telephoned the USCG District 8 HQ and spoke with a Coast Guard public affairs representative. He gave me an email address for further information. The email elicited a reply that pointed to the actual Notice to Mariners being found at

https://www.navcen.uscg.gov/pdf/lnms/lnm0817g2021.pdf

That documents is 90-pages long. A very careful reading of the 90-page document reveals that on page 40 the following information appears:

USCG Notice to Mariners wrote:Mariners making plans to transit offshore Tallahassee, Panama City and Pensacola, Florida, are advised of frequent rocket activity and associated hazardous areas which may include free falling debris and/or descending vehicles or vehicle components under various means of control.

Offshore Pensacola, bound by the following approximate positions:

29-55-48.0N 087-38-34.8W,
29-55-48.0N 087-21-25.2W,
29-40-12.0N 087-38-34.8W and
29-40-12.0N 087-21-25.2W.

Offshore Panama City, bound by the following approximate positions:
29-53-45.6N 086-10-15.6W,
29-53-45.6N 085-53-06.0W,
29-38-09.6N 086-10-15.6W and
29-38-09.6N 085-53-06.0W.

Offshore Tallahassee, bound by the following approximate positions:
29-22-48.0N 084-20-31.2W,
29-22-48.0N 084-03-28.8W,
29-07-12.0N 084-20-31.2W and
29-07-12.0N 084-03-28.8W.

Mariners should contact U.S. Coast Guard Sector Mobile at (251) 441-5976, for more information. Specific scheduled information and Marine Safety Information Bulletins (MSIB) can be found at the following website:

https://homeport.uscg.mil/port-directory/jacksonville/

Upcoming information and Hazardous Areas are also posted on the following Patrick Air Force Base website

https://www.patrick.af.mil/

or can be obtain by calling 1 (800) 470-7232.


The USCG is also (apparently) posting signs at shore facilities in the area, as shown below:

USCGsignReSpacecraft.png
Fig. 1. A USCG sign alerting mariners to spacecraft splashdowns.
USCGsignReSpacecraft.png (299.98 KiB) Viewed 727 times


The QR code encodes this URL:

https://www.navcen.uscg.gov/pdf/lnms/lnm0816g2021.pdf

The URL is the same URL as mentioned already to the 90-page PDF file. I cannot image that you could easily read a 90-page document on "your smartphone" and easily locate the information about exclusion zones on page 40 of the 90-page document.

Below is a drawing I created to show location of the four waypoints mentioned in the Notice to Mariners for the Panama City area:

USCGexclusionZonePanamaCity.jpg
Fig. 2. Exclusion zone plotted with four corner points from Notice to Mariners.
USCGexclusionZonePanamaCity.jpg (41.89 KiB) Viewed 719 times

From the inlet at Panama City to the nearest corner of the zone is about 18-miles. The perimeter of the square box is 70-miles, and the enclosed area is about 309-square-miles.

Re: USCG Notice to Mariners SpaceX Crew-1 Splashdown

Posted: Sun May 30, 2021 5:06 pm
by porthole
I found it interesting that our federal government and NASA could not give us a detailed time and location for the china rocket crash back to earth yet this SpaceX crew return was so accurate, even after being delayed a day or so due to weather that the small boat crews were on scene of the splashdown in under a minute.

If you watched it live you could see the small boats racing to the splashdown area in the same camera zone as the craft and parachutes.

Re: USCG Notice to Mariners SpaceX Crew-1 Splashdown

Posted: Mon May 31, 2021 9:25 am
by Jefecinco
I expect it was difficult to estimate the crash site of the Chinese craft due to uncertainties about it's mass and shape. I doubt the Chinese were very helpful supplying information. Once it entered the atmosphere it's trajectory could be computed quickly but by then it was close to impact.