Several members of the cult sci-fi series are due to reunite at this week's San Diego event to celebrate its 10th anniversary.
While there, they will also film a one-hour special to document the reunion, reports Entertainment Weekly.
Browncoats Unite will feature Nathan Fillion, Joss Whedon, Alan Tudyk, Summer Glau, Adam Baldwin, Sean Maher, showrunner Tim Minear, and writer Jose Molina.
The film will include footage from the show's panel. They will also shoot a special round-table discussion about the show, while also answering fan's questions.
The one-off show will air on the Science Channel in the US, and will be moderated by EW's Jeff Jensen.
Science's Debbie Myers said: "Firefly is a landmark work of science fiction and a favourite with our viewers. Ever since it premiered on Science, fans have asked us to do something special to mark its 10-year anniversary.
"With this signature celebration, punctuated by Browncoats Unite, we will connect the minds behind this classic franchise with its legions of passionate fans."
The special will air on Sunday, November 11 alongside a marathon of all Firefly episodes on the Science Channel.
Watch Nathan Fillion talk to Digital Spy about Firefly below: