Proton First Stage

Lifting Power 5/6
Fuel Capacity 5/6
Engine Restart Capability No
Manoverable No
Can Attach Payloads Yes
Can Attach Boosters No
Dockable No

The Proton First Stage is a medium-sized first stage , unlocked after the completion of Mission 11. It is used to make the Russian Proton rocket.This part is similar to the Soyuz First Stage in that it has pre attached boosters.It costs 15,000,000$ in Career Mode .