There was an achievement for doing something similar in the base game, so this guide follows a similar strategy.
Start up a game on the Classic Space Pack DLC. If you haven't used the Discovery Tool to "discover" a Space Buggy, spend some time on the moon, you'll find these cars everywhere. Here's a visual reference:
Once you've discovered the Space Buggy, hold
and select your Landscape Tool. Use it to build a tower straight up off the ground. Build it high, as you'll want the car to free fall for a minimum of three seconds!
Climb the tower (if your minifig didn't stay on it). Once on the top, use the Discovery Tool to place a Space Buggy. Drive off the side and fall to the lunar surface below. Achievement Unlocked!