Depends on how many you want to launch at a time - and the payload.
SpaceX intends to put 12,000 Starlink 400kg cubesats in two height layered constellations within the next 5 years, the payload capacity of a BFR when it enters service will be around 300-307 of them. Since the USAF is already talking seriously of becoming a major SpaceX BFR customer, how many do you think they, or the new Space Command, would have to launch in polar orbit to provide 24/7 one hour coverage?
Meanwhile, changing subject, the previous HMS Ocean has reached her new home.
https://www.snafu-solomon.com/2018/0...r-carrier.html
