Mission

Missions are the main game component in Warframe. Each mission has a specific objective, although the objective can change during the mission. The playable area in missions are randomly generated using "tiles" (pre-designed rooms and halls), and missions have a chance to include environmental hazards in the beginning of the mission. The Corpus and Grineer have two different sets of tiles, and the infected can be found on either one. For now, many Grineer missions are on Corpus tile sets.

Each mission is normally populated by one specific faction designated as the enemy, but it is possible for two different factions to appear in a mission (and are hostile between each other).

Completion of the objective and successful extraction nets the player bonus experience, credits, as well as the mission completion reward. It is not necessary to complete the mission to retain items obtained interim such as mods. Completion of the mission's bonus objective or challenge rewards the player with 500 affinity points to go towards his or her warframe/equipment. Further information on the Affinity page.

Trivia
The missions are all named after real physical locations and objects that exist in the solar system as recognized by the International Astronomical Union.

Which mission type do you prefer? (Leave a comment on why you like it!) Assassination Capture Deception Defense, Endless Defense, Mobile Exterminate Raid Rescue Sabotage Spy

Mission Info
Mousing over any node will give a mission description. This includes target (the faction populating the mission), Mission (the mission type, see below), and Level (range of levels of enemies expected). The mouse over will also reveal the user name of a solar land mark to honor a "Grand Master" contributor, shown in the bottom right of the planet info box.

Completing a mission will open up the next mission nodes. Missions completed will display a blue node. Missions available but not yet completed will show a yellow node. Missions that are not available for a player will appear as gray locks. Diamonds are links to other planets. The number of missions available to a player in a planet is given in the top right of the planet info box.

Game Modes
There are 3 game modes. Online, Private, and Solo.

In online mode, players will select a mission to play and be set into match making. The game will either wait for other players to start the game, or send you to play a match with players already in the mission. After a few seconds, the mode slector will change to "PLAY NOW" and flash. This will let the player start the game. While in game, other players may be placed into the mission. The number of squads already in the mission are displayed next to the missions name. This number is only displayed while you're in online mode.

In Private mode, a player can start any mission at any time, without waiting for match making, and only people from his/her clan or friends list can join.

In Solo, a player is on his own to finish the mission. He cannot join other parties and others cannot join him. Solo will disable some enemies, like Nervos.

Parties
Players can join together to play missions with up to three other players. A special lobby has been created to accommodate this. It is much like the regular mission menus, except there is a chat box to talk to players in the party, artifact cards are displayed (and stack), and the number of votes below the play mode selector reflects the number of players. While in party mode, a player cannot back out to the solar system view without leaving the party, but can access all other menus. Sometimes, the other players' warframes may be visible.

Team members will vote for missions to complete next. Once the vote is started, other players have 60 seconds to vote and use menus until the mission starts. If all votes are in, then the timer immediately counts from 5 seconds. The mission played will be the mission with the most votes. If there are an even number of votes, then it will default to the host member. A vote can be cancelled if the voted player leaves the party.

Parties can invite people to join while out of game. they can also be joined by players by going to the contacts list, right clicking, and selecting "Join Session." If there is space available, then the player will join the game, even if a mission is in progress.

Although a player cannot start a mission that is locked, he can play a locked mission while in a party. If anyone in a party can start a mission vote, then all players can vote for the same mission, regardless of a mission being locked to other players.

Parties less than four who do not want random players joining the game should change their game mode to "Private."

Alerts
Alerts are temporary missions that "spawn" randomly next to any other mission that players have previously unlocked (though not necessarily completed), this means that the more missions the players have unlocked, the higher the chance that the next alert will spawn. They can be of any mission type (noted in top of description window) and often have vague references to the mission type explained under "description." If the type selected is an assassination, the boss will have a chance to drop a blueprint, and the boss is a well known entity. (For example - Jackal when it comes to Corpus assassination alert missions). Alerts are temporary, they spawn linked to one of your available missions, and stay open until a given amount of time passes, or until the player completes the alert. The time is generaly between 20 and 50 minutes.

Alerts also give rewards, usually in the shape of more or less credits than usual (usually more), but sometimes they award special blueprints that the players can't obtain anywhere else. This can be recognized by having a "?" in the reward bar. Rewards are often Blueprints and Artifacts.

The difficulty of enemies (their levels) have little relation to the standard difficulty of the attached standard mission.

''At the time of this edit (Early April 2013), Alert missions on Mercury's Terminus level are broken and cannot be accepted. (From all of the reports, it seems to be for everyone, but cannot be confirmed at this time, unless by developers.)''

Mission Types
There are currently 10 types of mission in Warframe. Sometimes, a second mission (not a secondary objective) type will randomly be included, but will not be known until the first mission is completed.

Assassination
In this type of mission, players are required to find and eliminate the target, usually a unique enemy boss, and then return to extraction. Essentially the boss fight mission of the planet, these are the most commonly farmed missions, because they provide a chance to obtain blueprints or rare resources.

Capture
In this type of mission, players are required to find the target (so far always in the form of a Corpus Crewman regardless of the opposing faction), then incapacitate and capture said target before returning to extraction. Upon the player's discovery of the target, the target itself will begin to flee the room; while it is unconfirmed that the target can actually escape, it is not difficult to incapacitate him within a short time of discovery. It is also worth noting that the Crewman has comparatively much more health than its normal counterparts, however it does not stop to fight before running.

Unlike the hostage mission, there is no need to escort the quarry back to extraction. Instead, upon capture the target will let out an agonizing scream while slowly disappearing, after which Lotus will state rather ironically that the target has already been escorted safely to extraction.

Deception
Players will spawn next to a datamass looking object that must be picked up to complete the objective. Players are required to escort the data carrier or carry the data themselves to the ship's navigation core (usually) and upload the datamass to the target before returning to extraction.

Like a normal datamass, upon equipping the carrier will be reduced to pistols and switching to a rifle or incapacitation will drop the datamass. Therefore, these types of missions can prove difficult or at least more time-consuming when playing alone. A simple remedy would simply be to open up the game to Online, or to join a preexisting group.

This kind of mission has a chance of triggering the Timed Extraction event upon delivery of the datamass.

Defense
In this type of mission, players are required to defend an Orokin Cryopod. Players will start in a small room next to a larger one. On entering the larger room, waves of attackers will start entering the room. The objective is to keep the Orokin Cryopod, which is positioned in the middle of the large room, alive until waves of enemies are defeated. On what seems to be a Grineer Asteroid, there is a defense mission in which you defend an Orokin Reactor. The principles are the same, and it doesn't seem to be more difficult that the target is bigger, as enemies still need to get fairly close.

As an anti-frustration feature, the Cryopod and Reactor can regenerate its shields and health at a decent rate. However, at higher level difficulties, the sheer amount of tough enemies (especially on Infested missions) will easily overwhelm players, making it almost impossible to win without a team.

Mobile Defense
This type occurs on a Grineer Asteroid Base. Players will have to carry a datamass, similar to in Deception, to several computer terminals and upload it to them. Once uploaded at each terminal, players will have to defend the terminal until hacking is completed. Unlike normal Defense missions, these require players to defend for a set period of time instead of a set amount of waves. Players will also have to go through normal sized maps during the mission instead of having just one big room to fight in. There may be a final cryopod to defend before the end of this mission.

Endless Defense
In endless defense, the Tenno must keep a cryopod/reactor safe for at least 5 waves of enemies. After 5 waves, the players are given a choice to either take the ship out (they are extracted from where they stand) and get a reward, or stay and fight ever increasingly difficult enemies for better pickups and a better reward from the next out. This option continues either until the players choose to leave, or the cryopod/reactor is destroyed.

Exterminate
In this type of mission, players are simply required to kill all enemies in the area, and then make it to extraction (Corpus Security Cameras and Defense Turrets are not counted as targets when deducting from the to-kill total). There is a counter below the minimap showing the number of enemies left. Once the given number of enemies has been depleted, additional enemies will not spawn, thus allowing you and any party members a stress-free run to extraction.

Raid
In this type of mission, players are required to find an artifact, loot it, and return to extraction. This mission type is similar to Sabotage, the difference being Sabotage requires players to destroy a reactor core while Raid requires players to loot it.

Also, players will get a random mod as a mission reward on completion of a Raid mission. Unlike mods picked up from enemies, the reward mod has its card's picture on it on the mission summary screen.

Rescue
In this type of mission, players will be lead to a room with 12 prison cells, about half of which will be locked, and the rest hackable. The hostage is in one of the hackable cells. Once the hostage is free, the hostage will follow you while you head for extraction. The mission is failed if the hostage dies. Be careful, though, sometimes he tends to get stuck on short pathways, boxes etc. If freeing the hostage is impossible, a recommended course of action is to blaze to extraction as fast as possible, making sure to kill every enemy in the way. The hostage must simply be alive at the moment when the players reach extraction. It is unnecessary for the hostage to be present with the players at extraction for the mission to complete; therefore, if the players can reach extraction before possible harm is posed to the trapped hostage, all is not lost.

While it appears that the hostage has a pistol, he will never actually shoot and will instead take cover when possible. Enemies also tend to not attack the hostage intentionally. He also has a decent personal shield and health, so it is unlikely that the hostage will be put in any genuine danger.

Strangely enough, sometimes Lotus will make your secondary mission (not objective) another Rescue, which can sometimes be annoyingly difficult to keep both of them alive on harder difficulties. Along with that are the numerous AI bugs that are most likely associated with the fact that there probably shouldn't be 2 hostages.

Sabotage
In this type of mission, players are required to find the reactor room, and destroy the reactor core. To destroy the reactor core, players will need to expose the reactor fuel rods, then proceed to destroy each of the cylinders. When the reactor core has been destroyed, the players then are to return to extraction.

If the mission takes place on a Grineer Asteroid Base, an alternate version of the mission will occur in which players will instead be tasked with finding and destroying a number of Drilling Machines scattered around the map.

The missions that require the destruction of the reactor core have a chance of triggering the Timed Extraction event upon completion via the overhead message " Ship Integrity Compromised", while the missions requiring destruction of the Grineer Drilling Machines will not usually trigger a timed extraction.

Spy
In this type of missions, players are required to locate and hack up to 4 terminals. Once a terminal is hacked, a data mass will be raised on the platform next to it. Pick it up and proceed to the next terminal. Datamass stack (one player can carry all 4 data masses). While carrying a datamass, the carrier will switch to pistol. Switching to rifle drops the data mass. Players can still use melee while carrying the datamass though.

Lockdown
Sometimes enemies will activate "lockdown". This closes most doors, and players have to hack a control console to open them back up. However, this does not lock elevators. Depending on the situation, a lockdown can actually be beneficial for the player by locking out additional enemies and locking in of him/herself with a fixed number of enemies in the room, or put the player in serious trouble by the locking in of him/herself with said fixed number of enemies.

Note that enemies have to run to a control console themselves to activate lockdown. Killing them before they reach the console can prevent a lockdown.

Key Search
Sometimes when you encounter a locked door, players will have to search for a keypass before they can proceed; the keypass itself takes the form of a datamass and is picked up in much the same way. However, the rifle can still be used freely after aquisition. Once the keypass is obtained, the locked door can be opened and the mission continued.

Timed Extraction
Certain mission types can trigger a timed extraction upon completion. When you reach your goal, a timer will activate. If players do not reach the extraction point before the timer runs out, they will fail the mission. This is most problematic if an additional objective is triggered, especially a  rescue mission.

Additional Objective
Sometimes when players reach their primary goal (or even before the primary objective is completed), they will be informed that there is another objective. This can be any of the main objectives, even duplicated ones. For instance, the players have destroyed the reactor core, but instead of being given the extraction location, they are given the location of a hostage, and is required to rescue them before they can be extracted. This can coincide with the timed extraction event, making for a hectic run.

Environmental Hazards
Missions have a random chance of starting with an environmental hazard (excluding the atmosphere vent), which can increase the difficulty of the mission.

Self-Destruct
In this hazard, patches of fire are scattered across the map. Standing on the fire for longer than one second will damage the player. Enemies will be alert from the very start of the mission, even if the player has not been spotted yet. Some lootable corpses will also be scattered around the map. Note that the Self-Destruct hazard is different from the Timed Extraction event. There is no timer.

Cryogenic Leakage
In this hazard, the maximum amount of shields will be lowered by 50% for the duration of the mission. Patches of ice are scattered across the map for aesthetic effect. shield decrease affects both the players and enemy units.

Atmosphere Vent
Unlike the previous two hazards, this one occurs when a breakable window has been broken, either by bullets, melee, or an explosion. The occurrence of an atmosphere vent can be identified by the screen going blurry, sound getting a lot softer and silent, and both the player's and enemy units' shields start draining, or their health if their shield is already depleted. Breakable windows are identified as Reinforced Glass when pointed at and has a HP bar. In order to stop an atmosphere vent, you have to hack a nearby console to raise shields up over the broken window.

Note that not all windows are breakable, and that an atmosphere vent can sometimes be strategically triggered to lockdown a horde of enemies in what is literally a death chamber, as the event often locks down the room where the window was, though it is extremely inefficient.