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Why did thethis fairing separation happen at such a high altitude? (SpaceX Iridium-6/GRACE-FO)

I noticed in the video of the recent Iridium-6/GRACE-FO launch that the fairing separation happened at an altitude of about 147143 kilometers. This is significantly higher than any altitude I can remember. I first started watching this last year and noted the altitude for several launches here.

After seeing the 147143 km, I went back and checked several more recent SpaceX launches and compiled more numbers that can be compared with the table in the previous question. It seems Iridium-6/GRACE-FO stands out with a uniquely and significantly higher altitude for fairing separation than any other recent launch as well, including two other Iridium launches.

MISSION                speed  altitude  post 2nd stage 
                       km/hr    km      ignition (sec) 
-------                -----    ----    --------------  
Iridium-6/GRACE-FO     8754     147143          28 
Bangabandhu Sat- 1     8978     111          53 
TESS                   7055     107          24 
Iridium-15             8052     110          42 
HISPASAT 30W-6         8979     111          48 
PAZ Mission            6509     119          20 
CRS-14                 8158     115?         29 
GovSat-1               9222     111          52  
FH Test Roadster      10196     115          28 
Iridium-4              7578     111          30 
CRS-13                 5982     106?         32 

Why did the fairing separation happen at such a high altitude? (SpaceX Iridium-6/GRACE-FO)

I noticed in the video of the recent Iridium-6/GRACE-FO launch that the fairing separation happened at an altitude of about 147 kilometers. This is significantly higher than any altitude I can remember. I first started watching this last year and noted the altitude for several launches here.

After seeing the 147 km, I went back and checked several more recent SpaceX launches and compiled more numbers that can be compared with the table in the previous question. It seems Iridium-6/GRACE-FO stands out with a uniquely and significantly higher altitude for fairing separation than any other recent launch as well, including two other Iridium launches.

MISSION                speed  altitude  post 2nd stage 
                       km/hr    km      ignition (sec) 
-------                -----    ----    --------------  
Iridium-6/GRACE-FO     8754     147          28 
Bangabandhu Sat- 1     8978     111          53 
TESS                   7055     107          24 
Iridium-15             8052     110          42 
HISPASAT 30W-6         8979     111          48 
PAZ Mission            6509     119          20 
CRS-14                 8158     115?         29 
GovSat-1               9222     111          52  
FH Test Roadster      10196     115          28 
Iridium-4              7578     111          30 
CRS-13                 5982     106?         32 

Why did this fairing separation happen at such a high altitude? (SpaceX Iridium-6/GRACE-FO)

I noticed in the video of the recent Iridium-6/GRACE-FO launch that the fairing separation happened at an altitude of about 143 kilometers. This is significantly higher than any altitude I can remember. I first started watching this last year and noted the altitude for several launches here.

After seeing the 143 km, I went back and checked several more recent SpaceX launches and compiled more numbers that can be compared with the table in the previous question. It seems Iridium-6/GRACE-FO stands out with a uniquely and significantly higher altitude for fairing separation than any other recent launch as well, including two other Iridium launches.

MISSION                speed  altitude  post 2nd stage 
                       km/hr    km      ignition (sec) 
-------                -----    ----    --------------  
Iridium-6/GRACE-FO     8754     143          28 
Bangabandhu Sat- 1     8978     111          53 
TESS                   7055     107          24 
Iridium-15             8052     110          42 
HISPASAT 30W-6         8979     111          48 
PAZ Mission            6509     119          20 
CRS-14                 8158     115?         29 
GovSat-1               9222     111          52  
FH Test Roadster      10196     115          28 
Iridium-4              7578     111          30 
CRS-13                 5982     106?         32 
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Why did the fairing separation happen at such a high altitude? (SpaceX Iridium-6/GRACE-FO)

I noticed in the video of the recent Iridium-6/GRACE-FO launch that the fairing separation happened at an altitude of about 147 kilometers. This is significantly higher than any altitude I can remember. I first started watching this last year and noted the altitude for several launches here.

@awksp's excellent answer explains the relative constancy of the altitude as likely originating from a standardized spec. The answer is thorough and worth reading, but here is a snippet from there:

...after the 3-sigma high theoretical free molecular heating for a flat plate normal to the free stream drops below 1135 W/m$^2$ (360 Btu/hr ft$^2$) based on the 1962 United States Standard Atmosphere.

After seeing the 147 km, I went back and checked several more recent SpaceX launches and compiled more numbers that can be compared with the table in the previous question. It seems Iridium-6/GRACE-FO stands out with a uniquely and significantly higher altitude for fairing separation than any other recent launch as well, including two other Iridium launches.

Question: Why did the fairing separation here happen at such a high altitude compared to so many other SpaceX launches? Solar activity-induced atmospheric heating? Abundance of caution for this payload combo? Anomaly? Just to see if we're watching? Something else?

MISSION                speed  altitude  post 2nd stage 
                       km/hr    km      ignition (sec) 
-------                -----    ----    --------------  
Iridium-6/GRACE-FO     8754     147          28 
Bangabandhu Sat- 1     8978     111          53 
TESS                   7055     107          24 
Iridium-15             8052     110          42 
HISPASAT 30W-6         8979     111          48 
PAZ Mission            6509     119          20 
CRS-14                 8158     115?         29 
GovSat-1               9222     111          52  
FH Test Roadster      10196     115          28 
Iridium-4              7578     111          30 
CRS-13                 5982     106?         32 

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