Trip to the Stars

Trip to the Stars is a side quest in the Fallout 4 add-on Nuka-World.

Quick walkthrough
Gather 5 spacesuit costumes from the Vault-Tec: Among the Stars area of the Galactic Zone and bring them to Dara Hubbell. Follow the Hubologists to the Nuka-World junkyard to clear it from robots (either alone or with their help) or tell them you have cleared it already. For this Dara will reward you with the Hub's Alien Blaster. Once cleared, collect the power distributor and some fusion cores from the junkyard and go to the spaceship ride. Adding three cores, as Dara suggests, will result in a good end to the quest. However, adding the fourth core will result in the death of the Hubologists. Once at least 3 cores and the distributor are placed, the Hubologists will enter the spacecraft. Follow them inside and activate the ride to finish the quest. If you choose to not kill them, Dara gives you 100 ammo for the alien gun, and all the Hubologists relocate to the large barn northeast of the spaceship.

Detailed walkthrough
5-7 fusion cores can be found in the area: If you insert 4 fusion cores instead of 3, Dara and the rest of the Hubologists will explode on the spaceship ride. Either way, you will complete the quest.
 * In the subway car with a lantern hanging by the door. The car is at the bottom of the ramp from the spaceship. The core is on a shelf to the right as you enter.
 * Inside a large tea cup on a ledge above the aforementioned subway car, south of the spaceship.
 * In the nearby barn, there is a generator with a core.
 * In the same barn, the hanging gondola car has a core sitting on its floor. You may need power armor and a jet pack to reach it although a carefully timed jump from the floor above works too.
 * In a mounted bear's mouth, in a tunnel below the central pile with some crickets, ants and landmines.
 * Possibly two fusion cores from a sentry bot patrolling the area just outside the spaceship.

Reward

 * Hub's Alien Blaster received from Dara Hubbell.
 * 100 alien blaster rounds received from Dara if the Hubologists survive the spaceship ride.

Bugs

 * After bringing back the spacesuits and Dara telling the other Hubologists to suit up and arm themselves, the Hubologists run out as if they're holding their weapons at the ready, though their hands appear empty. When attacked they will fire with invisible laser pistols, with the rays coming from a random point in their body (toes or back for example). Upon death their weapon will become visible again and drops on the ground.
 * If the player installs the fusion core before talking to Dara after her speech, the quest may progress past stage 805 ("Install a power distributor") without the power distributor actually being installed.
 * If the Hubologists have not entered the space ship before activating the ride, the quest might not trigger completion.