HELIOS One

Helios One is a Poseidon Energy solar plant that can generate and provide power to the New Vegas Strip and other settlements in the Mojave Wasteland. It also contains the control system for two space-based weapon platforms, Archimedes I and Archimedes II.

Background
A pre-War installation, Helios was hailed as the "Dawn of a Golden Age" by Poseidon Energy. The Mojave Brotherhood of Steel discovered the facility and were trying to work out how the plant worked until the New California Republic (NCR) launched Operation: Sunburst to take Helios One. Before the Brotherhood abandoned the facility, they put it in a nearly inactive state and armed the pre-War security system. Despite the NCR's best efforts, they have had no luck in getting the plant to work to its potential or deactivating the security system.

Main building
At the beginning of the events of Fallout: New Vegas the facility is controlled by the NCR, who have a detachment guarding the facility. At the front entrance is Lt. Haggerty, who must be convinced to allow the player character in, or the player can lockpick a side door to gain entrance.

In the back of the building is a "technician", Fantastic, who is working on getting the power plant functioning; the room adjacent to Fantastic's contains another scientist, Ignacio Rivas. A nearby door leads to the mirror yard.

Mirror yard
Behind the main building is the solar collection tower and an array of computer-controlled mirrors. There are also two mirror control terminals in small shacks, and several tents set up by the NCR troopers guarding the facility. The western terminal is guarded by mines, bear traps, and a rigged shotgun, while the eastern terminal is guarded by attack dogs.

Solar collection tower
Inside the solar collection tower, past a small straight path there are three hostile automated turrets and several (level-dependent) security robots, a mix of protectrons, robobrains, Mister Gutsies, and/or sentry bots. Going straight ahead leads to an unlocked door to a small room containing several frag mines (both active and inactive) and an easy locked terminal. The terminal can be hacked to shut off the turrets or get them to fire indiscriminately at all targets (including the security robots). Near the entrance is a water fountain with no radiation. Downstairs is a small room with two pulse grenades on a shelf, and an average safe containing more pulse grenades and pulse mines plus miscellaneous loot.

The level continues through a double-wide door and down a sloping corridor guarded by a leveled security bot. The door at the bottom leads into another narrow corridor, leading to another multi-level room with stairways and catwalks, guarded by a Mister Gutsy.

At the bottom of the catwalks past the Mister Gutsy is a door leading to a corridor that branches left and a shorter one to the right ending at a door. The corridor to the left contains a single protectron in a shielded charging station, past which is a laser tripwired door (disarm with an 85 Repair or 67 Science skill). The room beyond contains four more protectrons also in shielded charging stations. The tripwire releases the shields and activates all five robots. The door to the right in the initial corridor opens into a room contains some desks, skeletons and two Poseidon Energy ID cards. Both paths have doors that adjoin the final room; which has an elevator that leads to the observation level of the tower.

Observation level
The observation level contains the mainframe computer used to activate the plant and direct its power, plus a broken generator that can provide power to the mainframe and a repair robot called Python. See That Lucky Old Sun for more about repairing and using the mainframe. There is a door at the top level that leads to the observation deck.A desk by the generator has a wooden box with embossed red symbols([!]-[X]-[H]-[A]-[H]-[X]-[@]) on it. It cannot be picked up but may be interacted with.

Observation deck
This is a circular deck all around the top of the solar collection tower. A spiral catwalk leads down from the entrance door. There is a reflector control panel that must be activated to complete the retargeting of the mirrors during That Lucky Old Sun. This location is outside, so the player can fast travel from here, though it is not recommended to do so during the Helios One/Archimedes I startup sequence, as this can cause quest glitches.

Notable loot

 * D.C. Journal of Internal Medicine upstairs in the main building, lying on a bed in the same room with the east terminal password. (Head to the right from main entrance, through the pool room, and right up the stairs.)
 * Big Book of Science can be acquired from Ignacio Rivas during the That Lucky Old Sun quest if the Player chooses to distribute the energy to the Full Region along with a large amount of Followers of the Apocalypse Reputation.

Appearances
Helios One appears in Fallout: New Vegas and is mentioned in Dead Money.

Behind the scenes

 * In Greek mythology, Helios was the Titan personification for the sun and in Greek (Ἥλιος) the word still translates to "sun".
 * This structure appears to be modeled after Solar Two located in the Mojave Desert in California, but the location is more similar to the unrelated Nevada Solar One southwest of Boulder City, Nevada.

Bugs

 * The NCR will be hostile towards you, even if you're idolized by them.
 * Sometimes when leaving the building via the back door, various non-player characters, creatures or invisible objects will fall out of the air and will become hostile. These may include Rey, Audaz, Colmillo, No-bark Noonan, Basura, Old Lady Gibson, mole rats, radscorpions, barrels, a tin can or a combination of the above. Reloading the autosave made when you exited the door will correct this problem. Also, it can freeze up the game.
 * A hostile protectron may be found in one of their blue glowing holding containers, and if you kill him while he is still in it you may become trapped inside. The only way to fix this is by reloading your last save (possibly the autosave upon entering).
 * Protectrons within the room with the laser tripwire seem to be immune to explosive damage.
 * Disarming the laser trip wire within the room with protectrons with science skill does not however prevent it from opening the forcefields and letting protectrons out to attack player.
 * The hostile protectrons in the blue glowing holding containers may occasionally detect the player if one of their body parts (usually their hands) clips outside the container and you touch it.
 * The hostile protectrons in the blue glowing holding containers can be disabled with Robotics Expert while inside the container. Somewhere between the waist and the feet, the cursor will typically change to red and you can "activate" the protectron and receive the option to disable it, as usual with the Robotics Expert perk.
 * The southwest room with the Mister Gutsy has two filing cabinets occupying the same place next to the sink.