Project Angel focused on cybernetics and the end goal of the project was the creation of the Hybrids — mechanical bodies from which humans could continue to live after their natural bodies have died. The Project was funded by the government in hope to help with battlefield injuries.
The project was important to Serena Kogan because she had been diagnosed with terminal cancer and was nearing her own death. Marcus Wright was one of the first subjects, having been one of the very first criminals legally allowed to donate his body to science.
Marcus' body was frozen and keep like this for a future in which he can be resurrected it later, along with Dr. Kogan herself. After Judgment Day, Dr. Kogan, resurrected as a cyborg, said than Marcus, in fact, was only a test subject, to learn and prepare for the resurrection of the real key subject, another executed prisoner, Thomas Parnell, who was planned to be a command unit: a psychopath killer to command all battlefield Terminator units.
In 2018, Skynet resurrected Project Angel under its new name, Project Theta, and used the town of Baker's Hollow as a test site. The name "Theta" comes from the term "T-H", another name for the Hybrids, as the letter TH is transliterated from the Greek alphabet "θ". 
Known Test Subjects
Behind the Scenes
- Project Angel and the Hybrid were originally the central note of the Terminator Salvation plotline. However, due to a leaked script which received overwhelmingly negative reviews from the fanbase, the idea was scrapped in favor of the final draft.
- Project Angel was a code name for the film Terminator Salvation during production.
- What went wrong with Terminator Salvation (featuring the original script) (From Internet Archive)
- Terminator: Trial by Fire - Terminator Episode Studies
- Hope Of The Future - Terminator Salvation deleted scenes - The original 3rd act (Project Angel) (More at: Hope Of The Future - Terminator Salvation deleted scenes)