Vice Admiral Margaret O. Parangosky was the senior officer in charge of the Office of Naval Intelligence. Born in 2461, Parangosky was tiny and aged, yet sharp and cold as ice, as would be expected of the head of ONI. Parangosky was a Rear Admiral by 2511, and a full Admiral by 2525. By 2531, however, she had apparently been demoted.
She was the ONI operative who first restricted the planet Onyx from the rest of the UNSC after they discovered Forerunner ruins on the surface of the planet in 2511. She would return several times to check up on and report on the project, but it was eventually sidelined so funding could go elsewhere.
In 2531, Parangosky was aboard the UNSC Point of No Return where she attended a meeting with Rear Admiral Rich and Captain Gibson where Colonel James Ackerson would propose the Spartan-III project. Parangosky approved the creation of Alpha Company, and authorized for Spartan-051 to be abducted and made head of the project.
In 2537, Parangosky again was aboard the Point of No Return, to authorize Beta Company following the death of Alpha Company in Operation: PROMETHEUS.