Inside the Nuka Galactic Zone is a large mainframe computer. If you interact with it, you'll begin a quest to rebuild the computer. To do so, you need to find 20 missing Star Cores. There are actually 35 in total, but only 20 are needed to flag the quest as completed.

All 35 Star Cores in Fallout 4

Below, are the locations of all 35 Star Cores.

Galactic Zone Star Cores

All of these Star Cores are found while roaming around in the open area of the Galactic Zone, not inside specific buildings.

Galactic Zone Star Core 1

This one is found inside Star Command, where the main computer is located.

Galactic Zone Star Core 2

This core is located on the second floor of Star Command.

Galactic Zone Star Core 3

Start by facing the Star Command building. Walk around behind it, and you will find there is a lot of trash and dumpsters. Amidst all this, will be a dead person, and a Star Core.

Galactic Zone Star Core 4

Start by facing the Star Command building. Walk up the stairs on the right, then once at the top turn left, then left again. Walk down the escalator, turn right then go straight towards the tunnel labeled Space Walk. At the end of this tunnel is the Star Core.

Galactic Zone Star Core 5

By the Nuka Galaxy attraction is a large red building named "Arcjet G-Force". Climb to the very top of the stairs inside this building to find a Star Core.

Galactic Zone Star Core 6

Near the entrance to the Nuka Galaxy attraction. Jump down the right side of the ramp to spot a tiny white shack, and inside is the Star Core.

Galactic Zone Star Core 7

This is likely the last core you will get. In order to obtain it, you must first Complete the main DLC quest and turn the parks power back on. Once you've done that, return to Star Control and use the elevator there. Rid it to the top to get the Star Core.

Starlight Interstellar Theatre Star Cores

All the following Star Cores are located inside the S.I Theatre which is located inside the Galactic Zone.

Starlight Interstellar Theatre Star Core 1

From the entrance, walk down the hall and turn into the viewing room, filled with rocketship seats. The core is in a console, in the back of this room.

Starlight Interstellar Theatre Star Core 2

Starting at the entrance, take the right hall, and turn right the first chance you can. This will lead to what looks like a kitchen area. There is a steel door in the back, lock pick it and you'll find the Star Core on the other side.

Starlight Interstellar Theatre Star Core 3

From the beginning of the area, head down the left hall until you reach the end. Turn left, then immediately right to enter the men's bathroom. In here there is a busted wall, with the Star Core laying within.

Starlight Interstellar Theatre Star Core 4

In a few locations, you can find an elevator up to the second floor catwalks. Up here, you'll find a steel door. Open it, then go down the stairs to find the Star Core.

Vault-Tec: Among The Stars Star Cores

The following 6 Star Cores are only located in the Vault-Tec: Among The Stars building.

VT:ATS Star Core 1, 2 and 3

In the starting area, there is a red door marked employees only. Open it, then go left once you enter the next room. There is a door that you will need to lock pick here. Once you do, you will find Star Cores 1, 2 and 3.

VT: ATS Star Core 4

While on tour through the Vault, you will pass by a small room that is dripping with Radiation, due to the huge Nuclear Power Generators inside. There is also a Star Core in this room, which we suggesting getting quickly, then getting out!

VT: ATS Star Core 5

During the tour, you will find a demonstration of colonizing a new planet. Tucked behind the rocks is a door, and behind that door will be the Star Core.

VT: ATS Star Core 6

While on the tour, you will enter the Residential Section, which is a mockup of the inside of a house livingroom/kitchen. There is a door by the couch, open it and on the other side you'll find a Star Core.

RobCo Battlezone Star Cores

The following Star Cores are only located within the RobCo Battlezone building.

RC Battlezone Star Core 1

From the entrance of the building, walk through the left door then down the stairs of the bleachers. Go through the tunnel that leads underneath the bleachers and you'll find a store. On the shelf behind the counter is the Star Core.

RC Battlezone Star Core 2

From the entrance of the Battlezone building, head through the right door, then go all the way to the right of the glass enclosure, where you will find a door. Open it then go downstairs to the robot maintenance area. In the red computer console is the Star Core.

RC Battlezone Star Core 3 & 4

From the entrance of the building, go through the left door, then immediately turn left 180 degrees. You will see a red door marked "Employees Only". Open this door, then go up to the control room where you will find Star Core 3 and 4.

RC Battlezone Star Core 5 & 6

Again, starting from the entrance, walk through the left door, then circle around to the left side of the glass enclosure. Open the door here, then go straight through the next door ahead of you. You will now be in the glass enclosure, and will see the two Star Cores.

Nuka Galaxy Star Cores

The following Star Cores are only found within the Nuka Galaxy attraction.

Nuka Galaxy Star Core 1

From the entrance, walk through the attraction until you reach the boarding area, as seen above. Once you find it, head to the right side of the room and unlock the door, then go inside to find the Star Core.

Nuka Galaxy Star Core 2

Directly across from Core 1. Exit the room Core 1 is in and walk straight. There will be another door on the opposite side of the room marked Employees Only. Enter it, then go upstairs to the red computer console where the Star Core can be found.

Nuka Galaxy Star Core 3

In the same room as Core 2, there is a silver door. Open it and it leads to a tiny room with two robots in it and white computer consoles. In the consoles, you'll find Core 3.

Nuka Galaxy Star Core 4

While going through the building, you will find a room filled with large, gray meteors. Shortly after you will walk down a long hall. At the end, on the left is a console with the Star Core in it.

Nuka Galaxy Star Core 5

While walking through the attraction, you will reach a point where the ride travels through a room filled with rocky terrain and various alien animatronics. In a computer console on some of the metal walkway you will find the Star Core.

Nuka Galaxy Star Core 6

Shortly after Core 2, you will climb a series of stairs until you reach a large, fairly empty room with a few model planets in it. In one of the corners is a computer console with a Star Core in it.

Nuka Galaxy Star Core 7

In the same room as the Nuka Girl outfit, there is a computer console with the Star Core in it.

Non Galaxy Zone Star Cores

The following 5 Star Cores aren't found in the Galaxy Zone, and are instead located in different locations around the main map.

Dry Rock Gulch Star Core

To find this core, start by meeting up with Sheriff Hawk, the robot who greets you the first time you enter the area. From here, walk past him, then turn left where the road splits. Walk about 30 more feet then turn left again and walk to the end of the road. There is a dead person with a Star Core beside them.

Nuka-World Junkyard Star Core

Located along the West side of the map, you will find the Junkyard. Enter the barn like building here, head through the door and upstairs, and at the far end is a computer console with the Star Core in it.

Nuka-Cade Star Core

Head inside the Nuka-Cade, walk straight to the back then turn right. Go through the Employee Only door, then into the room beyond. On a table in here is the Star Core.

Nuka-Cola Bottling Plant Star Core

While exploring the Nuka-Cola Bottling Plant, you will come across a room that glows with blue light due to a huge nuclear generator. Right beside this generator is a sealed door with a body beside it, and a Star Core.

Nuka-Town Market Star Core

One of the easier cores to find, simply go to the Town Market, and you will find the Star Core sitting at one of the vendors. Don't worry, you can take it without getting called a thief.