In 1947, Aperture Fixtures is founded by Cave Johnson as a shower curtain manufacturer (The name “Aperture Fixtures” was chosen “to make the curtains appear more hygienic” – Cave Johnson, founder and CEO.)

In 1956, the Eisenhower administration signs a contract with Aperture to manufacture shower curtains to all branches of the US Military, except the Navy.

From 1957 to 1973, the company produces mostly shower curtains and enjoys a great deal of success, making Cave Johnson a billionaire. As far as 1973, Aperture also uses a bulletin board system.

During this point, early work on the Aperture Science Handheld Portal Device began; the early version, called the Aperture Science Portable Quantum Tunneling Device, proved to be too bulky for effective use, while poor surface conductors for the portals often caused mangling or death of the test subjects when they tried to use the portals. Repulsion Gel was first developed around this time as well for use as a diet aid. At first only the brightest and best of society were chosen for testing, but after being connected to a string of astronaut disappearances in 1968, Aperture Science focused on recruiting homeless people for testing, starting in 1976. Cave suspects Black Mesa of industrial espionage on the company’s products, and blames them for Aperture’s bankruptcy. (Propulsion Gel was released around this time too.)

In 1974, Cave Johnson is exposed to toxic Conversion Gel, made out of ground-up moon rocks.

In 1976, both of Cave Johnson’s kidneys fail. Brain damaged, dying, and incapable of realizing time is not now flowing backwards (thus knowing his time will come soon), he lays out a three-tiered research and development program. The results, he says, will “guarantee the continued success of Aperture Science far into the fast-approaching distant past.”

The three tiers of this research and development program are:

Tier 1: The Heimlich Counter-Maneuver – “A reliable technique for interrupting the life-saving Heimlich Maneuver.”

Tier 2: The Take-A-Wish Foundation – “A charitable organization that will purchase wishes from the parents of terminally ill children and redistribute them to wish-deprived but otherwise healthy adults.” It counters the real-life Make-A-Wish Foundation, designed to grant wishes to terminally ill children.

Tier 3: The ‘Portal’ project – As described by Johnson when it was first laid out: “Some kind of rip in the fabric of space… That would… Well, it’d be like, I don’t know, something that would help with the shower curtains I guess. I haven’t worked this idea out as much as the wish-taking one.” This is what will become the ‘Portal’ project, involving the Aperture Science Handheld Portal Device and its creation of portals.

Post-Cave Johnson era

In 1981, Aperture engineers complete the Heimlich Counter-Maneuver and Take-A-Wish Foundation initiatives. The company announces products related to the research in a televised ceremony. Unsurprisingly, these products become immediately, wildly unpopular. After a string of highly publicized choking and despondent sick child disasters, senior company officials are summoned before a Senate investigative committee. During these proceedings, an engineer mentions that some progress has been made on Tier 3, the “man-sized ad hoc quantum tunnel through physical space, with possible applications as a shower curtain.” The committee is quickly permanently recessed, and Aperture is granted an open-ended contract to secretly continue research on the ‘Portal’ and Heimlich Counter-Maneuver projects.

From 1981 to 1985, work progresses on the ‘Portal’ project. During this time, several high ranking Fatah personnel choke to death on lamb chunks despite the intervention of their bodyguards, showing that the US government has apparently put the Heimlich Counter-Maneuver to work.

As far as 1982, the Enrichment Center, where Test Subjects undergo tests, is functioning, as the Enrichment Center Test Subject Application Process, a 50-question questionnaire destined for applying Test Subject, is already used at that time. It is unknown if the Enrichment Center is already “computer-aided” in 1982, as scientists have known to supervise them from small offices until an undetermined date. The Enrichment Center Test Subject Application is operated by version 1.07 of GLaDOS, later “1.07a” and “1.09”.

In 1985, the Aperture Image Format is created.

In 1985, the Aperture Image Format is maintained by Doug Rattmann.

In 1986, word reaches Aperture Science management that Black Mesa is working on a similar portal technology. In response to this news, Aperture Science begins developing GLaDOS.

In 1996, after a decade spent bringing the Disk Operating System parts of GLaDOS to a state of more or less basic functionality, work begins on the Genetic Lifeform component. During that time, the Aperture Science Red Phone plan is implemented in case GLaDOS appears to become sentient and godlike, requiring an employee to sit by a red phone on a desk in GLaDOS chamber’s entrance hall.

In 1997, GLaDOS’ version is 3.11.

In 1998, Aperture Science releases the Propulsion Gel to the public as a diet aid, serving as a dietetic pudding substitute made out of liquefied, slightly less non-toxic fiberglass insulation (i.e. slightly more toxic) and marketed under the name “Propulsion Pudding”. However it is a failure and must be pulled from shelves. Later that year a new formula, the Repulsion Gel, is released, and is another failure. Both Gels are subsequently recycled for use with the ASHPD in Test Chambers instead. The same year, Aperture releases other testing elements, such as the Excursion Funnel, a tractor beam-like funnel made of liquid asbestos, the Thermal Discouragement Beam, a laser to be used with a Weighted Pivot Cube to destroy Sentry Guns and activate some buttons, the Aerial Faith Plate, a catapult plate flinging into the air Test Subjects or any other object upon contact, and the Pneumatic Diversity Vent, a variant of the Vital Apparatus Vent used for distributing objects to Test Chambers.

In May 1998, the untested AI of GLaDOS is activated for the first time as one of the planned activities on Aperture’s first annual bring-your-daughter-to-work day. Upon being activated, she almost instantly becomes self-aware, takes control of the facility, locks everyone inside, floods the Enrichment Center with a deadly neurotoxin, but is partially halted when she is quickly fitted with a Morality Core. She then begins a permanent cycle of testing, aimed at beating Black Mesa in the race to develop functioning portal technology. However a few days later, on May 16, the Black Mesa Incident occurs at the Black Mesa Research Facility, allowing aliens to teleport from Xen to Earth, eventually leading to the Combine invasion, stopping GLaDOS’ race against Black Mesa.

GLaDOS’ control

As seen in the hacker message found on ApertureScience.com referring to the lockdown, the remaining employees continue working, as they are said to be working on twenty year old equipment. The construction of an Enrichment Center is also mentioned, suggesting that the Aperture Laboratories house several of them. The number of Aperture Science employees also likely diminishes, until there are only a few of them left. The Aperture Science Handheld Portal Device is likely already completed at that time, but it is unknown if it is before or after GLaDOS’ activation.

During that period, Portal Storms continue to rage on Earth and spread chaos, eventually leading to the Seven Hour War, resulting in Earth being defeated and subsequently controlled by the Combine. Later, around 20 years after GLaDOS’ activation, Gordon Freeman is awakened from his stasis by the G-Man, and arrives in City 17, which greatly disturbs the Combine’s grasp on Earth.

Portal era

Some time after GLaDOS’ takeover of Aperture Laboratories and shortly after the Combine invasion of Earth, the Enrichment Center seems to be long abandoned, and GLaDOS seems to rule it alone, although other people are apparently still trapped somewhere. The scribblings left by Rattmann also seem rather old, showing that the Enrichment Center has been partially abandoned for some time. A calendar named “The girls of Aperture Science”, dated 1983, is also rather worn-out. Chell is awakened in her Relaxation Vault in the Enrichment Center, and is guided as a Test Subject by GLaDOS, utilizing the completed ASHPD, while the A.I. shows signs of instability. When GLaDOS attempts to murder Chell at the end of her tests, she flees through maintenance areas of the Enrichment Center, and eventually seemingly destroys GLaDOS, before being dragged away inside by the Party Escort Bot.

Before her partial destruction, GLaDOS hints to Chell that things have changed since the last time she left the building, and that what is going on out there will make her wish she were back in here. GLaDOS also says she was the only thing standing between them [GLaDOS and Chell] and an undetermined group, most likely the Combine.