# Why is the tip of this Russian ICBM folding/closing during launch?

This question refers to the page on which a YouTube video Soviet Missile SS-18 Satan / Most Powerful Rocket is shown. Screenshots below are from circa 01:10 for example and for those who can view it there are other launch sequences in this clip as well.

Can anyone explain why does the nose cone of this Soviet Missile SS-18 Satan ballistic missile fold when the ICBM is launched?

What is the reason for this?

click for larger

Sequence of cropped stills

From the explanation under the video:

The R-36 (Russian: Р-36) is a family of intercontinental ballistic missiles (ICBMs) and space launch vehicles (Tsyklon) designed by the Soviet Union during the Cold War. The original R-36 was deployed under the GRAU index 8K67 and was given the NATO reporting name SS-9 Scarp. It was able to carry three warheads and was the first Soviet MIRV (multiple independently targetable reentry vehicle) missile. The later version, the R-36M was produced under the GRAU designations 15A14 and 15A18 and was given the NATO reporting name SS-18 Satan. This missile was viewed by certain United States analysts as giving the Soviet Union first strike advantage over the U.S., particularly because of its rapid silo-reload ability, very heavy throw weight and extremely large number of re-entry vehicles. Some versions of the R-36M were deployed with 10 warheads and up to 40 penetration aids and the missile's high throw-weight made it theoretically capable of carrying more warheads or penetration aids. Contemporary U.S. missiles, such as the Minuteman III, carried up to three warheads at most.

The R36 became the base for the Tsyklon launch vehicles family. As of early 2018, Cyclone-4M, the last modification of it, is developed and planned for launch in 2020.

Russia intends to replace the R-36M with a new heavy ICBM, the RS-28 Sarmat.

• While it's in no way unanswerable, I suspect this is hard to answer due to countries with ICBMs being stingy with detailed information. Nov 13, 2020 at 15:34
• Eh, obviously it's folding/closing to provide a good sharp aerodynamic nose cone required for a rocket to fly with minimum losses. The better question is why is it starting with an open nose cone and blunt front, instead of just having a normal, solid nose cone like every other rocket.
– SF.
Nov 13, 2020 at 15:39
• Comments are not for extended discussion; this conversation has been moved to chat. Nov 13, 2020 at 15:41
• @SF probably to fit into the silo. Nov 13, 2020 at 15:42
• Apparently these are also used for launching satellites: ‘Satan’ launches five Japanese satellites into orbit. No folding nose here. But comes out of the silo like a bat out of hell. Nov 13, 2020 at 23:36