From Destinypedia, the Destiny wiki
To activate this event, you must interact with one of several in-ground towers stationed around BrayTech Futurescape and Glacial Drift on Mars. These towers will have an orange aura on top of them for easy recognition. Once activated, the tower will rise and a beacon will shine, signaling where a tower has been activated. There are seven timed levels of this event, and completing one will progress you to the next.
The first level has four stages and features mostly thrall enemies. The first stage requires you to simply eliminate enemies until a message is displayed. The next stage requires you to close a shadowrift that was opened somewhere in the nearby vicinity. Shadowrifts will continue to spawn hive Acolytes, three at a time. Not closing one results in not progressing and a surplus of enemies. To close one, you must stand in it until the timer reaches 100, and then shoot the three crystals nearby it. Once a shadow rift has been closed, a Major Severing Knight will spawn from it. Killing it drops its sword. The third stage requires you to kill more enemies. The forth stage is the boss stage. For level 1, the boss is a Shambling Torrent. This process repeats itself from level 1 through 6.
To move on to another level, you must find another tower that has been raised. A beacon will shine for easier location. Approach it and interact with it to begin the next level. The second level repeats the exact same process as the first one with the exception that the featured enemy is either the Cursed Thrall or the Acolyte. Also, enemies will begin to increase in rank as you progress further. Wizards will start to spawn on this level as well. The boss for the second level is the Soaring Keen.
Find another tower to activate the third level. This is the shortest level, with only three stages instead of four. The featured enemy is the Vanquisher. This time when you have to disable a shadowrift, there will be two you must disable instead of one. After disabling the shadowrifts, the boss will appear. The Choking Blade is probably the easiest boss, attacking only with melee attacks that don't do too much damage.
Repeat the same process with level four. The featured enemy is the Knight and there are once again four stages and two shadowrifts. The boss of this level is the Deafening Blast. A useful tip for this event to to kill an Interceptor Pilot an operate its Interceptor.
Level Five has four stages and starts summoning Ogres. There are three shadowrifts this time. There are two bosses for this level, two Shambling Torrents, as well as a Renewal Wizard. This wizard does not need to be killed to progress, but can prove to be annoying because it will slowly heal any Hive combatant that stands within the wide green circle it summons.
Level six is basically level five repeated with the exception that almost every combatant is a major. The bosses are two Deafening Blasts and another Renewal Wizard that again does not need to be killed.
Level Seven is the final boss stage. It is always in the same location for each region of Mars. It features only one stage and a high health boss that has a mechanic that makes it trickier to defeat. In addition to a huge number of enemies, there are three elite Shriekers hovering above the battlefield. It is recommended to eliminate them quickly. Once completed, the boss will drop a loot chest. This chest has a piece of IKELOS armor in it. In addition to the chest, it drops a legendary shader and occasionally an IKELOS weapon.
Escalation Protocol Delays any public events that may happen soon. When doing Escalation Protocol, An event will sometimes be incorporated into it. To progress to the next level, you must complete the heroic event and defeat all hive bosses. This only happens during levels 2 though 6. When completed, the usual event loot chest will drop, and you will progress to the next level.
Attempting to solo this is not recommended even at level one. The large number of enemies plowing toward you can wipe you out in seconds, wasting time and most likely causing you to fail the level. Failing to complete a level will end the event. If you restart immediately after failing, you can pick up one level short of where you left off.