One thing about sci-fi games is that they often let you fly around in your sleek space ships, zooming through the atmosphere. And that's what you'll be doing in the False Flags Over Castrovel encounter that Paizo has posted for Starfinder.
From the website:
The following starship encounter takes place in the atmosphere of Castrovel, and can be incorporated into any Starfinder campaign with little to no alteration. For more information on starship combat in atmospheres, check out the Starship Operations Manual. While the encounter was designed with Starfinder Flip-Mat: Planetary Atmosphere in mind, you can use any hex grid to run it.
This encounter is Average difficulty for a group of PCs flying a tier-4 starship, but your PCs may be higher or lower in level. “False Flags over Castrovel” is an Easy encounter for 5th-level PCs, Challenging for 3rd-level PCs, Hard for 2nd-level PCs, and Epic for 1st-level PCs.