Testing track

A testing track is a term used by Aperture Science to refer to a set of test chambers meant to test an Aperture Science product. The first testing tracks used by Aperture Science consisted of a deep shafts containing Spheres which would hold a test chamber. These early test chambers, unlike those built and managed by GlaDOS, would begin with volunteer test subjects waiting in a lobby and exiting via an elevator to the surface once the testing track was completed (presuming the volunteer test subject does not die during testing). This contrasts with the later testing tracks in which GlaDOS kills the test subject in the final test chamber.