You'll first need a k-drive.
To get one you need to complete the introduction mission when first arriving in Fortuna.Ideally you'll want an Archwing too.
To get one you'll need to complete "The Archwing" quest and then you'll need to research and build the Archwing Launcher from the Tenno Lab.
To make sure you've got enough distance, just put a marker down using up on the d-pad and you'll see how far you are from the landing zone.Video of both methods here: https://xboxdvr.com/gamer/xdakx/video/69210324There are two ways of doing this:If you've got an Archwing:
(This is the method I used)
Just walk out of Fortuna, get in your Archwing and fly directly above the big lake of coolant right outside in front of you and when you can't fly any higher, just open the gear wheel and change to your k-drive. You'll fall down into the coolant and the achievement will pop once you land. You don't need to actually be on the coolant tower, it wouldn't surprise me if you even have to be close to it.If you don't have an Archwing:
You will need to climb the coolant tower that is directly in front of you as you walk out into Orb Vallis. It's doable, but you have to do a lot of wall jumping and deal with awful clipping issues. Once you get to the top, just activate your k-drive and boost and jump off and hope you don't hit anything on the way down that forces you to climb it again.