That Lucky Old Sun

 is a quest in Fallout: New Vegas. It is also an achievement on the Xbox 360 and PC; and a bronze trophy on the PlayStation 3.

Objectives and Walkthrough
WARNING: If you want to use Helios One as a weapon you MUST activate Archimedes II

When you first approach the Helios One station from the south, you will be approached by a female NCR officer by the name of Lt. Haggerty. With either a successful speech check, a science skill option, or good reputation with the NCR you can convince her to allow you inside, and that you should talk to the "idiot wearing sunglasses". If you can't muster any of these options you can simply sneak in through a back door which is locked (very easy) located behind the Lt. with only minor Karma loss and no NCR hostility or reputation loss (although you'll have to use this entrance every time).

Proceed to the back of the factory, following the compass. You will soon come across a door with a light above it; this leads to the NCR's de-facto science lab at the power station. The "Idiot wearing sunglasses" is a man by the name of Fantastic, who explains that he got the job by lying to NCR when they were going door to door, asking if anybody knew a scientist.

You will get the password to the other (western terminal) from him and the place you can direct the power to. Next you must speak to Ignacio Rivas in the next room. He will explain that the HELIOS One-station is not only a power plant, but also a developmental facility for a weapon known as "ARCHIMEDES", and that he has kept the NCR in the dark about the weapon, fearing what they may do with it. He will also give you the password for the eastern set of mirrors (only if you tell him you support PEACE; if you tell him you support war you will have to find the password else where and you cannot prompt him again for the password), and explain that you must go to the control computers for the mirrors, attempt to reconnect with the mainframe, then go to the mainframe to redirect the mirrors, and direct the power. Also, if you don't tell him you support peace, you will not get any rewards from him for choosing the Followers of the Apocalypse oriented choices.

Proceed out the back door into the mirror field, and head for the control computers, which are each located in small shacks nestled among the mirrors. The shacks are guarded with traps and attack dogs, and can be dangerous, and possibly lethal to an unwary player. After you reset the mirror control computers, you must enter the tower through a door at the base. If you go straight (quickly) and make it the door (past the turrets) you can hack a terminal to turn off the Mark III turrets. (Note: disabling the turrets does not disable the Protectrons.) Or you can simply fight your way through Mark III Turrets and Protectrons till you get to the bottom of the basement, where a working elevator takes you to the mainframe.

NOTE: You need at least 35 Repair and 1 Scrap Metal to access the mainframe due to lack of sufficient power which requires you to use an auxiliary generator next to the mainframe. Or if you go to the upper level of the same room, towards the back there is an offline Mr. Gutsy named Python, which you can interact with if you possess a Poseidon Energy employee I.D. or having at least 45 Science, the robot will then fix the generator for you.

NOTE: To find the Poseidon Energy Employee I.D.:  After entering the tower eventually you will come to a long tunnel. After going down the long tunnel turn left, and left again. You will have to fight a sentry bot, Mr. Gutsy and Protectron to get through. Then there will be a set of metal stairs. Descend the stairs and enter the doorway. Take the hallway right, this will lead to offices on the left. Around the corner and to the right of the first one there is a half skeleton, right next to it is the Poseidon Energy employee I.D. If you are backtracking from the generator room then simply go back through the metal door, through the room with the bunker and go to the left side of the left room.

NOTE: The eastern terminal password can also be found on a desk on the second floor. Go right from the front desk, to a staircase to the second floor and take the holotape that is on a desk.

Time for some choices.

McCarran and Las Vegas Strip
Select the first option, "McCarran and Las Vegas Strip", exit the mainframe, take the stairs up and follow your compass to outside. Once outside, go down the spiral stairs and activate the Reflector Control Panel and enjoy the show. After your screen turns normal, go back to Fantastic and listen how he tells you he's going to take most of the credit. This will get you 350 XP and New California Republic reputation.

Fremont and Westside
Select the second option, "Fremont and Westside", as your grid configuration, go outside and activate the Reflector Control Panel to enjoy the show. When you have seen enough, return to Ignacio Rivas to be congratulated on your well made choice. He will tell that hopefully NCR's curiosity in the plant has been satisfied and they won't dig any deeper. You will gain 350 XP, 3 Stimpaks, 2 Doctor's Bags and a moderate amount of Followers of the Apocalypse reputation.

Full region
(See Bugs Below) Select the third option, "Full region", as your grid configuration, go outside and activate the Reflector Control Panel to enjoy the show. When you have seen enough, return to Ignacio Rivas to be congratulated on your very admirable choice. He will tell that hopefully NCR's curiosity in the plant has been satisfied and they won't dig any deeper. You will gain 1 Big Book of Science, 350 XP, 3 Stimpaks, 2 Doctor's Bags and A LOT OF Followers of the Apocalypse reputation (this will get you to the status of Accepted if you haven't had a previous encounter with them).

Archimedes II
Select the fourth option, "Archimedes II", as your grid configuration. A new menu item called "Arm ARCHIMEDES II Plant Defense System" will appear. Here you have 2 options. Both will grant 350 XP and you will be able to use Euclid's C-Finder as a laser designator for an orbital strike.
 * If you choose to arm the plant defense system, an alarm will sound warning personnel to get inside. Go outside and activate the Reflector Control Panel to enjoy the show. When you have seen enough, return to Ignacio Rivas. Ignacio won't interact with you and Fantastic will yell at you for killing his employers. You will lose reputation points with the NCR and you will not receive any rewards from Ignacio. But you can be rewarded with spoils of war. After all nearby NCR troops are decimated by ARCHIMEDES, loot their bodies for many Service Rifles, Combat Knifes, as well as NCR armor.
 * Alternatively, you can choose not to arm the plant defense system and only receive 2 Stimpaks from Ignacio.

Full region (Emergency output level)
Select the fifth option, "Full region (Emergency output level)" as your grid configuration, go outside and activate the Reflector Control Panel to enjoy the show. When you have seen enough, return to Ignacio Rivas who will be disappointed of all the energy wasted, but he will be relieved as the plant can not be used as a weapon anymore. You will gain 350 XP, 3 Stimpaks, 2 Doctor's Bags and Followers of the Apocalypse reputation. However, you will also lose some NCR reputation.

Bugs

 * Full Region (Emergency output level) has a glitch. When you talk to Ignacio and tell him that "I overloaded the plant. No one will be able to use it to power a weapon.", the option will stay meaning that you can get infinite Experience Points, Stimpaks, Doctor's Bags. Confirmed on Xbox 360. Update 10/23/2010: works on PC and PS3 too.


 * A bug causes the quest to finish, but without getting any rewards (only XP). -Happened on PC with the option selected "full region". -Same happens for PS3 (10/23/2010) confirmed on Xbox 360, (10/24/2010). You need to talk to Ignacio Rivas first and say that you are with the Followers of the Apocalypse. Then it will work and you get the Big Book of Science and Rep. for the Followers.


 * there seems to be also a bug in the PC version making it impossible in some cases to access the mainframe after putting the two terminals online.


 * There is a bug in the PC version where the player doesn't get the achievement upon completion of the quest. -happened with ARCHIMEDES II activated.


 * If you choose Python to repair the generator for you, you can kill Python, leaving electricity flying in the air to nothing and the generator will not be fixed. But by waiting at least 1 hour Python will resume with 1 health and resume work on the generator.


 * There is a bug in the Xbox 360 version that prevents the player from viewing the two terminal computers in the field


 * There is a bug in the PS3 version that doesn't allow you to hack computer terminals nor pick safes in the solar collection tower. Also could not use scope on 9mm handgun (just shows black screen when trying to use scope. same problem when hacking).


 * Running across the corridor to the room with the console to disable the turrents when first entering below, the room has mines on the floor that go off. If you jump on the table to avoid them sometimes you get stuck, unable to move and a reload is needed.


 * Some choice of conversations with Ignacio (or something else?) can cause him to not give you the password to the second terminal, making you either have to pickpocket it from him (losing karma) or having to hack the terminal (very hard difficulty?) to be able to continue. (issue happened on PC)


 * If you are doing the NCR quest chain and go to Hoover Dam to talk to the Commander before you finish the quest, Fantastic will be there instead of HELIOS one, meaning it is impossible to finish if it tells you to talk to Fantastic.