In the spawn of both BLU and RED team of powerhouse. There is a Green Box, what is in it is a bunch of square black, rocks, and if you played Rd_Asteroid, you might remember below the bridge there are rocks that look just like this.So we can say it is a hint to Moonbase. People have the idea it might be iron blocks, due to the liquid seen in the pit on rd_asteroid.

The Rocket Launch Room is a room behind both RED and BLU spawns. It seems VERY suspicious due to all the other Moonbase References in This map.

There is a window to the left of the rocket launch room where you can see, has a Rd_asteriod Style Computer and Door, and has the Moonbase Textures. This is a reference to Moonbase.

Inside Both the RED and BLU Bases. There is a rocket below the floor, in a silo. It has a opening door above it, and on the roof right above the rocket. There is a slighty opened square door. Like a hangar door. Which probably both doors would open for the rocket to launch.There is also a wire that goes down into the silo that contects to a unique computer. On it, it reads "rdy" which mean ready, and that means the rocket is ready to launch.

In Both RED and BLU bases above a computer there is a smalll board with papers, even though there are many boards in the map, this is unique. The board Contains Teasers to moonbase.
One is the Dropship that flies at the end of the round in Rd_asteroid. Second is a newspaper which talks about the Moon landing.
The third is a Picture of a monkey, probably Poopy Joe. Lasty, we have on the same paper with poopy joe, below him is a drawing of an U.F.O. (Utmostannoyingandunknown notbymanncomadeFlying Obstacleforrocketjumpers). These U.F.O.s are seen in many maps on secret places, after the latest update.

Just across the room with the Board there is another Computer with a Choclate Milk Class on the Left side, but on the right is a Turned on Screen. that reads.

launch Sequence: 111.........1. This is a reference to Meet the spy when the soldier says 111 uhhh 1! Also, This is probably the Launch Sequence For the Rockets in Rocket Room.

Next we have:Poopy Joe. Well, its a reference to Poopy Joe, but this also a refernce to Space.

Below it Reads: Capacity Lolololol. Capacity probably deals with the rocket, The lolololol probably references to the "Copyright Lolololol" on the TF2 Meet the Team promotional Fims.

Then lastly it says: Velocity. Probably Deals with the rocket launch.

The part with the Rectaglar grid that has a bunch of dots and a Crosshair. Is a reference to the movie Alien.

All this leads to moonbase probably.

These are all the ones i have heard about and known about. We probably will find some more. I will make sure to add those. Also, if i missed any. Leave that in comments and i'll add it. Well Thanks For Listening to This artwork, happy easter egg hunting and Get hyped for Moonbase.