From Team Fortress Wiki
| Failure to Launch|
Kill 3 players riding the elevator within 10 seconds.
How to obtain: Once your opponents start to raise the elevator, there are a few ways to access it. You can use an explosive jump as the Soldier or Demoman, leap from nearby high ground as the Pyro or Heavy, or pick off enemies from afar as the Sniper.
Push a player into the rocket's exhaust path at the end of the round.
How to obtain: As the round ends, make sure you're fighting an enemy below the rocket, where exhaust fumes are dispersed. These fumes will push anyone in their way into the nearby crevice. Using a source of knock back, such as the Force-A-Nature or compression blast, can make forcing an enemy into the exhaust path easier.
| Mission Control|
Pick up the Australium from its home position and capture it without dropping it.
How to obtain: At the beginning of the round or after the Australium returns to its initial position, grab it make your way towards the rocket. Because you'll need to keep the Australium safe for a long time, have teammates protect you and constantly be on the move to dodge enemy fire.
| Flight Crew|
Play in a game with 5 or more players from your Friends list.
How to obtain: Joining a regular group of friends who play together can expedite the process.
| Escape Ferocity|
Kill an enemy who has damaged the Australium carrier in the last 3 seconds.
How to obtain: The Australium carrier will glow and be seen through walls, so enemies can easily target him. Protect the carrier by eliminating any enemies that attack him. If you are carrying the Australium, the achievement is obtainable by killing an enemy that damages you.
| The Fight Stuff|
Win 138 Rounds.
How to obtain: This achievement will naturally be obtained after a very, very significant amount of time playing on Doomsday.
Win a round with at least 5 teammates on the elevator.
How to obtain: Multiple teammates should gather on the elevator to protect the Australium carrier. Having five or more allies on the capture point will give your team a decisive advantage when trying to secure the area. Because you and your allies will be clustered, stay wary for stray explosives or Sniper shots.
| Best Case Scenario|
Kill 6 enemies carrying the Australium during the same round.
How to obtain: To kill the Australium carrier six times, you'll need to make the round last a significant amount of time. Be patient and try not to shut down your enemies too much. The achievement is more likely to happen naturally if the two teams are evenly matched.
| Plan Nine to Outer Space|
Launch the rocket as all 9 classes.
How to obtain: Choose a class and play as it until you are able to launch the rocket. Repeat this process with all nine classes.
| Rocket Booster|
Win a round after the enemy team has opened the rocket lid.
How to obtain: If the enemy manages to raise the elevator to the point that the rocket lid is being opened, they are very close to victory. Your team should kill the Australium carrier before the case is secured, defend the case until it returns to the drop site, then take the case for themselves. The rocket lid will stay open; instead of completely repeating the launch cycle normally, your team can then have a mobile class, such as the Scout, Soldier, or Demoman, maneuver to the top of the rocket to immediately deposit the Australium and win the round.
| Space Camp|
Kill an enemy within the broken crate area while they attempt to pick up the neutral Australium.
How to obtain: The neutral Australium appears in the crate area at the beginning of a round or when it resets after a team fails to capture it. When this happens, stay near the area and kill an enemy as they stand on top of the Australium. If attempting this at the beginning of a round, you'll need to wait for the Australium to actually become available for pickup, which will occur after 45 seconds.