1 janv. 1978 - Aperture Science begins using homeless people as Test Subjects due to legal issues. (Portal 2 - Mentioned)

Description:

- 1978
- Aperture Science constructs the elevator out of the Propulsion Gel Testing Facility.
- Due to financial difficulties and possible legal problems arising from testing prominent citizens, Aperture Science begins using homeless people as Test Subjects.
- The object of testing and experimentation at this time is Propulsion Gel.
- Complementing the Propulsion Gel testing, Aperture Science also begins experimenting with human deconstruction, enhancement, and reconstruction procedures.