The Sky Marshal is the highest rank given to members of the the Federal Military.
Starship Troopers novel
Not much is known about the Sky Marshal as the title is only mentioned for few time in the novel. It is noted that to become Sky Marshal, one has to come up through both Fleet and Mobile Infantry. One can start as a trooper and switch to pilot or the other way 'round, but a single track won't do it.
Starship Troopers anime
The highest rank is called simply "Marshal" (元帥 Gensui).
Starship Troopers film universe
The title "Sky Marshal" consisted of commanding the entire forces of the Federal Military; it can only be achieved if the candidate has had training in both Mobile Infantry and Fleet. Sky Marshal is open to members of either gender. All eligible candidates are put infront of the advisory board, which consists of military strategists and retired Citizens. The board would simultaneously vote on the Sky Marshal. However, their minds would often be swayed due to current events in the United Citizen Federation, such as the events running up to the promotion of Admiral Enolo Phid to Sky Marshal was well recieved due to the fact she had lied and tried to cover up the loss of the current Sky Marshal Omar Anoke.
Known Sky Marshals
The Sky Marshal dress uniform in Starship Troopers 3: Marauder is uncannily similar to the uniform of Reichsmarschall Hermann Göring. In relation to Anoke's "German" uniform, the uniform in which Enolo Phid wore appears to be a lot similar to our modern day navy uniform, Which is understandable seeing as her previous rank was admiral. And the previous two Sky Marshal's uniforms that looked more Mobile Infantry-based than the last two.
In all films, there are five known Sky Marshals. So far, nothing has been revealed pertaining to their elite circle. As soon as the Sky Marshal made one mistake, they "retired", which implies they were pressured into it. And for all we know, there seemed to be another Sky Marshal between Meru and Anoke.
Roughnecks: Starship Troopers Chronicles
Known Sky Marshals
- Starship Troopers episode "Maria"