I hear what you're saying, and I agree— it would be incredibly dangerous; a fool's errand... But aren't the true fools the ones who don't seize an opportunity, despite all the inherent risks? And I'd be able to show Steven the wonders of the cosmos! And maybe, just for a second, from a distance, I could see what's been going on without me. All right! Let's do it!
The Crystal Gems and Steven arrive at a location covered with several damaged warp pads. With each Gem stepping on a Warp, they all say they are inactive. Steven puts a "Crying Breakfast Friends" sticker on each inactive warp. Steven asks Pearl where all the Warp pads lead to, Pearl explains that they used to be used for inter-dimensional space travel. All of them unfortunately have been deemed inactive for thousands of years. Pearl as she explains this, seems to lament the fact that she's stuck on earth forever, but is comforted that she's there with Steven.
The next day, Steven watches "Crying Breakfast Friends!" with his father. Realizing that Pearl really misses space, Steven convinces his dad to help him build a spaceship for Pearl. To help him out, Greg shows Steven his Aunt and Uncle's shed, as the couple were fairly invested in flight, and the fact that they kept every single one of their belongings in the shed. Using the things in the shed, Greg and Steven are able to build a small, measly, car-looking "space ship". Before testing it out, Greg tells Steven that it's alright to bail, and that there's no shame in knowing when to bail. The ship then fails to actually launch once they've shown it to Pearl. Disappointed, Pearl lectures the two on proper aerodynamics of space shuttles and ends up inspiring herself into building one of her own.
Through several montages, the trio uses leftover parts from the shed to build a prototype out of an upgraded engine and a hang-glider. Once Steven tests it out and lands it (and it purposefully falls apart), Greg discovers that Pearl really is serious about taking Steven up into space. Refusing to let him go, Greg claims that he's "grounding" Steven, "grounding" as in he's not able to leave earth. Angry, Pearl decides that she'll just do it herself, and disgruntledly shuts herself into the shed.
While Steven and Greg are sleeping, Pearl wakes Steven up to show him the ship. Amazed, Steven climbs up into the ship while Pearl asks him to do an engine test with her. Agreeing, Pearl and Steven excitedly start up the ship and launch into the sky. Greg, who awoke due to the sound and blast of the engine, tries to convince Pearl to land. Pearl tells Greg not to worry, as she's only going to take Steven to the nearest star system and return him in 50 years, surprising Greg and Steven alike.
Up in the Earth's atmosphere, Steven witnesses continual damage to the ship, and realizes that if they continue flying, the ship will be destroyed. Ignorant and yearning to visit space again, Pearl continues to push the limits of the ship, and doesn't realize their fate until Steven releases the emergency hatch on the window. Steven tries to convince Pearl to abandon the ship, but as Pearl won't listen, he grabs her head, and says "Sometimes, you just gotta know when to bail." Finally listening, Pearl ejects the two of them out of the ship last minute, and sadly watches it explode. Greg is shocked to see the ship explode thinking that they died in the explosion but is relieved to know that they escaped in time and curls up into a fetal position. Apologizing, Pearl regrets nearly killing Steven, but Steven reassures Pearl that he's used to it and she'll get into space one day. Pearl, shaken by the experience, says she would rather stay on Earth. Steven says "With me" and Pearl replies "Yeah, with you." They smile at each other as the star shaped iris closes in on them.
- Greg's uncle (pictured and mentioned)
- Greg's aunt (pictured and mentioned)
- After These Messages
- UUU Fanfare / Let's Build a Spaceship: Part 1
- Blast Off!
- Let's Build A Spaceship: Part 2
- Almost There
- Its revealed that there is a Gem Homeworld, and the Gems aren't only based on Earth. The Crystal Gems are, however, stuck on Earth with no way off for the time being, due to the Galaxy Warp warp pads being broken.
- Pearl's space uniform has a pink diamond on it. It is unknown why this symbol appears on her, as diamonds are later revealed to be the symbol of the Homeworld Gems. It could be left over from the time when Pearl was still loyal to the Homeworld, or it could the original insignia of the Crystal Gems.
- The pink diamonds appear on the shoes of Sardonyx.
- The Crystal Gems annually test a "defunct" warp pad station.
- This marks the second time that Steven had been put in mortal danger by a Gem, Pearl, the first being when Lapis Lazuli tried to drown him and Connie in the episode "Ocean Gem".
- This is the first episode in which more of Steven's relatives are mentioned, besides his father and mother.
- It is pointed out that the Universe family might have a hoarding problem.
- Pearl is shown to miss traveling the cosmos even more than Amethyst and Garnet, so much so that she risks her and Steven's lives, but only due to being homesick, however she did understand that she got a little too carried away.
- The Cookie Cat theme can be heard playing on the television set after Steven asks Greg to help him build a space ship.
- This episode hints that Pearl does not like living on Earth, much like Lapis Lazuli, as long as she doesn't think about it too much.
- "Mach 3" meant that, assuming the spaceship was nearing the end of Earth's atmosphere, the spaceship was able to travel at 3 times the speed of sound, or above 1000 m/s (meters per second), or, in other words, about 5,880 mph (miles per hour).
- Assuming Pearl is referring the Alpha Centauri (and not an undiscovered star system even closer), a "pop over" that would return within fifty years would mean that the ship can travel at roughly 17% of the speed of light, or 51,000 km/s (kilometers per second).
- When Pearl asks if any of the local stores carry F-1 single nozzle liquid-fueled rockets, she is likely referring to the Rocketdyne F-1 engines used in the Saturn V rockets during the 1960s and 1970s.
- The title is an allusion to the competition between USA and Russia to launch a functioning space craft into outer space.
- There appears to be an Apollo Lunar Module in the background of Greg's storage shed.
- The reference sheet on Pearl's tears are named "Ghibli Tears", an allusion to how the characters cry in Studio Ghibli animations.
- Naming the experimental spacecraft "Mach 2" and "Mach 3" may be a reference to the Mach Five racecar from Speed racer.
- UUU could be a reference to the land of OOO from Adventure Time, another show Rebecca Sugar has worked on.
- This is the first episode that the Galaxy Warp is shown, which was first mentioned in "Mirror Gem".
- This episode marks the second time Steven gets "grounded", but this time by Greg. The first time was was by Garnet in the episode "Mirror Gem".
- Though, Greg's version of "grounding" was different, meaning that Steven was not allowed to leave Earth.
View the episode's transcript here.