Ostensibly a civilian astronomical research laboratory, ATLAS was actually a military weather modification project: the Atmospheric Terraforming Laser Accelerator System. It enjoyed limited success in its early months, mostly due to the apparent incompetence of Major Kirk Bentley. By the time he was replaced by Lt. Col. James Oberlin on January 24, 2076, the project was facing an ultimatum: Yield scaleable results by April or be shut down. 
Under Oberlin's oversight, the project moved ahead at a rapid pace. By March 12, prototype results started yielding effects: Dr. Hammond had succeeded in initiating light rainfall across a significant localized area. Funding for the ATLAS Program was provisionally extended under the condition that Hammond invest more research into more high energy weather conditions. Oberlin also gave ATLAS engineers the go-ahead to initiate construction of the accelerator even before the technology was complete. He did not inform Hammond of this fact in order to "encourage" the doctor to work more intensively and avoid significant development delays. 
This approach bore fruit. By August 20, the doctor has been able to produce a wide variety of weather conditions based on the data his team has been bringing into the lab. The latest prototype resulted in near-whiteout blizzard conditions, an unusual occurrence in mid-August. Some of the local media picked up on it, but not to the degree that the project could be endangered. Oberlin was confident enough in the project to advocate for it during a meeting in the Pentagon, seeing a number of uses for the technology. The localized prototype was not going to be be much use in a war on its own, except during small skirmishes or certain clandestine operations. ATLAS needed funding to thrive.
He was successful. Over the next year, the Pentagon funneled men and manpower into the project, apparently convinced by Oberlin's logic that the system could diminish the threat of nuclear war by attacking the enemy with weather. They could blanket a nation in thick black clouds until the crops die out, wipe out naval ports with typhoons, or send fierce lightning storms against vulnerable air bases to ground air units.
Despite Oberlin's enthusiasm for the initiative, the ATLAS project was scrapped in October. Much to his surprise, the Pentagon cited the sheer cost of the project and associated risks. Although it made little sense to him, Oberlin planned to carry out his duties. Hammond, the head of the project, took the news poorly and had to be restrained by MPs to avoid hurting himself or others. Meanwhile, Oberlin started doing what he was ordered to: Falsify the data so that it made the project look like a failure. He knew better than to ask questions.
In spite of this and the ensuing Great War, Hammond continued to work on the project for another five months, replacing lenses, analyzing particles, stabilizing the accelerator, activating security robots and measures in the facility all to protect him and his life's work. Eventually ATLAS neared completion, but the fate of the project remains unknown.
The observatory caps the crest of the hill along route 63 east of Monongah and is well marked on the map. There are three entrances to the building, which is encircled by cars, junk and equipment to the south and east. The exterior of the building is well guarded by protectrons, eyebots, the occasional Mister Gutsy, and automated wall turrets. The east entrance is flanked by a laser turret on the south side, while the south double door is flanked by a machine gun turret on its west side. Both of these turrets have line of sight to an approach from route 63, towards the eastern door, complicating efforts to clear the exterior of robots. The north door is locked with a level 2 skill check and is flanked by a powerful machine gun turret - 3 shot. Approaching from the west towards this door will give the player high ground and some cover from which they can attack relatively safely. A well-aimed grenade can take out the powerful turret with minimal risk.
The building is a multi-level structure with border rooms encircling a vaulted central room that houses the telescope. The building is seemingly filled with protectrons, a few higher level Mister Gutsies and an assaultron of the greatest strength among them. Navigating the dark building whilst dispatching the robot occupants can be difficult. The building is full of loot and junk, including a Vault-Tec bobblehead in the main telescope room (see notable loot section).
- ATLAS utility key (2):
- On a table in the basement by a section of collapsed roof.
- On a table in the lower level near the door to the basement that the key opens.
- ATLAS research log #104 - Holotape, inside the Scientific Director's office on a control console.
- ATLAS research log #293 - Holotape, near a skeleton in the center of the basement.
- ATLAS director's password - Holotape, near a skeleton in the center of the basement.
- Potential Vault-Tec bobblehead - At the top of the ramp surrounding the telescope.
- Potential magazine - On a coffee table, on the first floor from the basement.
The ATLAS Observatory appears only in Fallout 76.
- ↑ ATLAS Observatory terminal entries: Report [1-24-76]
- ↑ ATLAS Observatory terminal entries: Report [3-12-76]
- ↑ ATLAS Observatory terminal entries: Report [08-20-76]
- ↑ ATLAS Observatory terminal entries: Report [8-17-77]
- ↑ ATLAS Observatory terminal entries: Report [10-18-77]
- ↑ ATLAS Observatory terminal entries: Report [8-22-77]
- ↑ ATLAS research log 293