Commander Sarah Palmer (voice by Jennifer Hale) is a Spartan-IV stationed on UNSC Infinity and the leader of the Spartan IVs. She appears in Halo 4, Halo 5: Guardians, Halo: Spartan Assault, "Halo: Shadows of Reach", and the Halo Escalation comic series.
In this game she is the protagonist.

STORY:
Sarah Palmer was an ODST, the best of her company, and went on to become one of the first recruits in the ONI's SPARTAN-IV project. He boarded the UNSC Infinity as a captain, the purpose of which was to find the location of the Halo Installations to study and eventually dismantle them. When the Composer, located on Installation 03, pulverized scientists who were studying him, he provided coordinates that led the ship to the shield planet Requiem. Once the Infinty crashed on the planet, Palmer was sent to recon the land, where I met the Master Chief, who helped the team repel the attack and return to the ship.

After the battle ended, when Captain Del Rio was relieved of office, Palmer became second in command after Lasky. He personally knew numerous Spartan teams, including the Majestic Squad, and provided radio support and guidance to those in the field. He spent a lot of time on the Infinity, helping Captain Lasky plan the attacks. When Dr. Halsey was brought to the ship, Sarah was hostile towards her, given her past actions, even threatening her multiple times. During the assault on Infinity he protected the crew, especially Lasky, from the attack of the Knights. But when the command came to neutralize Halsey, since she had been captured by Jul 'Mdama, Sarah personally offered to carry out the mission, despite Lasky's insistence. Arriving at the lair, after eliminating several Elite, she hit the doctor in the shoulder, just before she was kidnapped and taken away by 'Mdama.

It appears very often in Spartan Ops, both in videos and in communications during missions.

BIOGRAPHY:
Early life and career

Sarah Palmer was born on Luna on April 13, 2527. Despite their proximity to the home planet, her parents harbored a strong dislike of the UNSC. Palmer did not share her parents' view and would later join the Marines, eventually serving twelve tours on eight worlds as an ODST. Palmer was considered a great asset by ONI due to her physical prowess and innate leadership.


(HALO: Spartan Assault cover of the game featuring Spartan Sarah Palmer)

(Palmer fighting on board the UNSC Infinity during the Promethean attack)

1. In the Halo 4 Infinity mission, Palmer tells Master Chief the famous phrase "I thought you'd be taller.", although he is at least ten centimeters taller.
2. In the Spartan Ops videos she is almost always seen without a helmet. The first time you see him wearing it is in fact in the video of the ninth chapter.
3. Sarah Palmer stands 2.05 meters (6 ft 9 in) tall and weighs 109 pounds.


(Palmer upon meeting John-117)

Halo 4 (First appearance)
Spartan Ops
Halo: Spartan Assault
Halo: Initiation
Halo: Escalation
Halo 5: Guardians
Halo: New Blood
Halo: Bad Blood