From Halopedia, the Halo wiki
Sergeant Laura Tanner (call sign: Smokes) was a UNSC Marine pilot serving on Earth in 2552.
She was the pilot of a D77H-TCI Pelican dropship, possibly based out of Base Segundo Terra near Mexico City on Earth. During the Battle of Havana in early November 2552, Tanner and her crew chief, Corporal Jim Higgins, provided transportation for Spartans Frederic-104, Linda-058 and William-043 as they were sent to counter a Covenant incursion in Havana, Cuba.
She is a chewer of tobacco gum, and her call sign "Smokes" suggests she has a fondness for tobacco in general.