Taken are everywhere, so try not to kill them (especially the major Lieutenants) and they go away faster. The War Sat has a chance to land where you Spawn in (the Barrens), In the Scab Lands (Cabal base where Vex and Cabal fight) and near the Buried City (where the Vex are). The Scablands and Buried City have a 50% chance of a WarSat dropping. The Barrens it's a 33% chance. The Destiny Public Events site: http://destinypublicevents.com/ is usually accurate to within +/- 5 minutes. I would just cruise on my Sparrow in a repeating loop between the 3 places until the events start happening. And I completed a War Sat last week when I was doing a Mars patrol for Cabal bounties. So they still happen. HTH..

Get a friend split up and head to the scablands/buried city

If it's for Sleeper Simulant, you don't. The "drop" rate for Warsats on Mars with that quest active is virtually non-existant. The Taken have ruined that whole planet. Best of luck Guardian.

You gotta go to that little shack where the hobgoblins and minataur hangs out.