Stock Proton K/D

[tehmattguy]

Proton

The Proton was born as the "UR-500", a two-stage super heavy ICBM. With the addition of a third stage it was reworked to serve as a heavy launch platform for the Soviet Union. It was then named "Proton-K" after some of its first payloads, the Proton satellites. In its decades of service it launched a wide array of missions, from space stations to interplanetary probes and landers.

The K/D version uses the "Block D" upper stage in its stack. This stage was originally used to boost unmanned Zond spacecraft around the moon. It was later used to boost probes as far as Mars and Venus. 

(Left) Proton K/DM carrying the EchoStar VIII satellite launched in 2002. (Right) My Proton K/D replica built in KSP at 3/4 scale.

 

Stage 1

Spoiler

 

The first stage of the Proton rocket is powered by six RD-253 engines, generating a combined 9.5 meganewtons of thrust. Each engine can be gimbaled up to 7.5° along a single axis providing directional control. Most notable is the stage's unique layout, featuring six long fuel tanks side-mounted to a core oxidizer tank. This design was born from a need to transport components by rail.

In order to fit on Soviet trains the rocket's diameter was constrained to 4.1 meters, the maximum size allowable. But a conventional inline tank design would have become too tall, making it difficult to access the upper stages and payload. Instead, engineers proposed to reconfigure the stage into a compact "polyblock" design, attaching fuel to the side of the oxidizer tank. This design also improved flight and structural characteristics and was ultimately chosen to be implemented.

 

 

 

Stage 2

Spoiler

 

Stage 2's engines ignite before separation, with exhaust gasses passing through the lattice interstage structure. This ensures constant acceleration and eliminates the need for ullage motors between stages.

Separation sequence: (1) Stage 1 engine shutdown. (2) Stage 1 falls away. (3) Interstage ring jettison.

Stage 2 is powered by four RD-0210 engines, providing 2.3 meganewtons of thrust. Each engine can gimbal up to 3.25° with command from the flight computer.

 

 

Stage 3

Spoiler

 

Stage 3's steering engines are started early, to act as ullage motors during separation.

Braking motors on Stage 2 aid in separation. 

Stage 3 main engine start

Stage 3 is powered by a singe RD-0213 coupled with a four chamber steering engine RD-0214. Together they are designated RD-0212. The third stage also houses avionics for the first three stages of the rocket.

 

 

Stage 4, Block D

Spoiler

 

Stage 3 separates using braking motors. Block D is released from its fairing.

The Block D is an upper stage designed to operate for multiple days in space. It was originally designed for use on the N1 moon rocket as its 5th stage. It was later adapted for use on Proton.

It consists of a spherical oxidizer tank and a toroidal fuel tank encased in structural supports. The fuel tank is inclined for better fuel extraction. Thrusters below the fuel tank provide attitude control.

 

 

If you'd like to see the rest of the mission (Venera 9) you can read about it here: https://imgur.com/a/dTFtu6p

 

The craft was built in stock KSP v1.5.1, using 493 parts. Stage timings written in the description. Download here: https://www.dropbox.com/s/9crpw4exedgcrz3/Proton-K D-1.craft?dl=0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited December 17, 2018 by tehmattguy

[qzgy]

This is gorgeous. Nice work with it.

[Majorjim!]

Great work! Its a very nice replica indeed. Its been a very long time since I played KSP and so I have not seen some of the new parts. Is the body of the rocket made from fairings?

[tehmattguy]

1 hour ago, Majorjim! said:

Great work! Its a very nice replica indeed. Its been a very long time since I played KSP and so I have not seen some of the new parts. Is the body of the rocket made from fairings?

Thank you! And yes it is indeed mostly fairings, also radiator panels to hide where the fairings end. Very useful for creating custom fuselage shapes!

[MaianTrey]

Yea, this is nothing short of terrific. I especially like the 'Proton' marking on the side, very nice touch!

[Majorjim!]

20 hours ago, tehmattguy said:

Thank you! And yes it is indeed mostly fairings, also radiator panels to hide where the fairings end. Very useful for creating custom fuselage shapes!

Agreed! Ive done it myself, its a very versatile part!

[Mad Rocket Scientist]

That is an excellent replica. Props on making a working interstage ring, they love to try to stick to the upper stage.