Apologies if this has been discussed (I did do a search) but is it possible that SD might be compatible with o2's satellite upgrade package? Designed to allow messaging/data apps to be used away from normal coverage it seems an ideal way to obtain a cost effective way of updating SD in flight. As some of the apps utilising it are map and navigation based I wondered if it might be worth investigating.

See more here: 

https://www.o2.co.uk/satellite