What is the fine-grained topic of the following text: WOTN Director of Flight Operations Shawn Hokuf provided a briefing to the Navy ROTC team, and Commander Carter and WOTN Museum Director Bob Jasperson signed a joint letter to Mr. Bush stating, “On the 75th anniversary of this flight, we remember the great courage and dedication to service and selflessness you have exhibited throughout your life. Only return the topic.
Briefing and letter signing to honor someone's 75th anniversary of flight service