That Lucky Old Sun

That Lucky Old Sun is a side quest in Fallout: New Vegas. It is also an achievement/trophy.

Synopsis
If Helios One's efficiency is brought up, it could power the Mojave Wasteland; however, Helios One hides a deadly secret deep within the facility as well: Archimedes II.

Walkthrough

 * 1) When asked by Lieutentant Haggerty the nature of the Courier's visit, one can lie with a Speech check of 30, claiming that their brother is stationed at Helios One, or note that the facility's tower is not working correctly and offer to help fix it with a Science of 30. Also, if the Courier has a reputation with the New California Republic, they can walk inside with little issue.
 * 2) Talk to Fantastic and Ignacio Rivas and get their passwords to access the mainframe. Rivas will only share his password if convinced that the Courier is working with the interests of the Followers of the Apocalypse. Otherwise, it can be pickpocketed off him.
 * 3) Use the two reflector control terminals outside to connect to the HELIOS One mainframe.
 * 4) Get to the mainframe and repair its electronics. This can be done by repairing the generator with a piece of scrap metal and a Repair check of 35, or by activating the maintenance robot Python by passing a Science check of 45 or using the Poseidon Energy employee ID card.
 * 5) Choose where to distribute power and whether or not to arm the ARCHIMEDES defense system and wipe out the NCR.
 * 6) Distributing power to Camp McCarran and the New Vegas Strip results in NCR fame.
 * 7) Distributing power to Freeside and Westside pleases the Followers of the Apocalypse, but won't benefit as many people as it potentially could.
 * 8) Distributing power to the full region, resulting in people getting the same small amount of energy with frequent brownouts. This option results in fame among the Followers of the Apocalypse, as well as a Big Book of Science, three stimpaks, and two doctor's bags from Ignacio Rivas.
 * 9) Diverting power to Archimedes II allows the Courier to use Euclid's C-Finder to call down an orbital laser once every 24 hours.
 * 10) Distributing power to the full region at emergency output levels overloads the plant and results in no fame, but Rivas will hand out the stimpaks and doctor's bags, but not the big Book of Science.
 * 11) Get outside and initiate reflector retargeting from the console.

Behind the scenes

 * The title of this quest is a cultural reference to the 1949 song, "That Lucky Old Sun", by Beasley Smith and Haven Gillespie.
 * The passwords to the Eastern and Western Reflector Control terminals can be converted from hexadecimal into ASCII, producing the phrases "My voice is my passport." and "Too many secrets". The phrases are originally from the movie Sneakers (1992), starring Robert Redford. They were used as computer passwords in that movie.


 * A number of remaining resources indicate that at one point this quest included a method for completing it on behalf of the Brotherhood of Steel, allowing them to take over the facility. Among other resources, the quest includes greeting dialogue for Brotherhood guards, indicating their satisfaction at gaining control of HELIOS One. Other unused resources include the guards themselves (FormID ) as well as the corresponding dialogue faction for these guards.

Bugs

 * If Fantastic is killed before the power is restored, Ignacio Rivas may not provide the quest-ending dialogue option after powering up the plant and the quest cannot be completed. If this happens the only way to complete is to kill Ignacio at a loss of Karma, and reputation with the Followers of the Apocalypse.
 * If the player leaves the room after activating Python, but before he does the fixes to the generator, he will be deactivated when walking back inside again, and will not perform the fixes.
 * If you obtain the password for the second terminal without talking to Rivas and activate Archimedes II, Rivas will refuse to talk to you afterward and the quest cannot be completed. Alternately, kill Rivas and the quest will complete or fail but no XP or Loot will be given to the Courier.
 * If you are doing the NCR quest chain and go to Hoover Dam to talk to the Colonel Moore before you finish That Lucky Old Sun, Fantastic will be there instead of Helios One, meaning it is impossible to finish if it tells you to talk to Fantastic. Sometimes, it actually seems to work to go to the Hoover Dam and simply kill Fantastic to complete the quest. The guards will not get hostile if this trick works. Unclear however, how this fix affects any further quests.
 * If you fast travel away before the sequence after using the switch on the tower finishes, the end quest dialogue with Ignacio is missing from the speech options. You can still finish the quest by killing him.
 * Sometimes when you go to select your choice of how to distribute power at the mainframe, and you have Gannon in your party, his speech options will not come through. This makes it one unable to retrieve the trust points needed to obtain Gannon's quest.
 * Sometimes the guard dogs guarding one of the terminals may not appear.
 * Choosing to disarm the Archimedes defense system after activating it may not work; the sequence may play anyway.