The Expansions are eight in-app purchases of Spaceflight Simulator. Each expansion adds new features to the installation of game, like parts, skins, planets and cheats, and can be restored in any future installation signed into the Apple ID or Google account it was bought from. If a user already bought the full version from version 1.4, then they get all of the 4 new expansions for free for being an early supporter.
Originally, there was a single expansion when it was added in 1.3, until it was divided into several in 1.5.
If the player is offline, the expansions will be disabled until their device becomes online. It was fixed in the 1.5.2.5 update. More expansions are then added in 1.5.4 update.
Expansion list[]
| Expansions | Prices | Summarised Additions |
| Parts Expansion | $4.99 | Larger variants of parts, and addition of new parts, such as Titan Engine, Frontier Engine, Ion Engine. The battery and RTG are still available even without this expansion. |
| Skins Expansion | $2.99 | Skins with different selections for fuel tanks, separators, nose cones and fairings. |
| Planets Expansion | $3.99 | Jupiter, the Galilean moons, and the Planet Editor are unlocked. In the future updates, they will add several gas giants (Saturn, Uranus, Neptune), and Pluto and Charon instead would be unlocked by this expansion. |
| Cheats | $4.99 | Unlocks cheats in the game, such as making rockets invincible, have infinite fuel, turn off gravity, and turn off atmospheric drag and reentry heat. |
| Infinite Build Area | $2.99 | Unlocks the infinite build space cheat, which you can make large rockets out of that, especially the ones that need more fuel in most complex missions. |
| Builder Bundle | $5.99 | Unlocks both the Parts and Skins Expansion. |
| Sandbox Bundle | $5.99 | Unlocks all cheats and infinite build area. |
| Full Bundle | $11.99 | Unlocks all expansions. |
| Redstone Atlas Pack | $3.29 | Unlocks Mercury-Redstone and Mercury=Atlas rocket parts. Also some Redstone-Atlas skins. |