Titan IIIC MOL
Can be build completely out of Lego bricks.
About the MOC
The three stages, as well as the two boosters can be seperated. On top of the transtage is the MOL mockup.
About the rocket
The Titan IIIC rocket with the MOL payload was launched in 1966 on the C-9 vehicle. It served as a mockup and was made out of a Titan propellant tank and a refurbished Gemini spacecraft. The laboratory mockup remained in orbit until 1967.