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Michael Duitsman Profile picture
Michael Duitsman
@DuitsmanMS
Research Associate @CNS_Updates. Rocket propulsion and radiological security (usually not at the same time). Opinions my own. Faves/RTs ≠ endorsements
Sep 26 • 4 tweets • 2 min read
Oh, I think I recognize that failure mode. There are 3 possibilities:

Failure during propellant loading
Failure during launch preparation
Failure to ignite on launch

but... First stage ignition failure is the one that came to mind first. Sarmat is cold-launched. The missile is ejected from the silo by a small solid propellant "pressure accumulator." The first stage engine does not ignite until the missile leaves the silo.
Aug 21, 2023 • 19 tweets • 7 min read
Someone mentioned the 4D10 (the rocket engine in the R-27/SS-N-6) on Twitter.

The 4D10 is one of the reasons I got into rocket propulsion. It's also a ridiculously complex engine.

(I put this together in a hurry, so it's a bit short of pictures.)
2/18 As Dr. Postol mentioned, the 4D10 is a submerged engine. On the vast majority of liquid-propellant missiles and rockets, the engine(s) are mounted below the propellant tanks.

Image
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Apr 16, 2022 • 4 tweets • 2 min read
I think it's very unlikely that Moskva was carrying nuclear warheads.

However, if it was carrying nuclear warheads, two is probably the right number. 1/4 In his 2012 paper, Igor Sutyagin estimates that the Slava-class cruisers had 4 warheads assigned to them - 2 nuclear-armed SS-N-12 anti-ship missiles, 1 nuclear-armed SA-N-6 surface-to-air missile, and 1 nuclear depth bomb for the ship's helicopter. europeanleadershipnetwork.org/commentary/ato…
Mar 15, 2022 • 7 tweets • 3 min read
I had initially filed these under "huh, that's interesting." In retrospect, I'm really embarrassed that we didn't follow this more closely. 1/7 2/7 For the longest time, we'd wondered what these circular caps on bottom of the missile were for. Now we know: they're covers for penetration aid tubes.

During the terminal part of its flight, the Iskander-M can poop out up to six penetration aids. But what are they?
Feb 25, 2022 • 30 tweets • 11 min read
The Russian encampment is at 46.7627° N, 33.3847° E. The column of vehicles was headed southeast (away from the Kakhovka hydroelectric dam) on the R-47.

#OSINTatMIIS #Ukraine Another vehicle, this time alone. Moving rather fast (for a truck) with its emergency flashers on.
Feb 8, 2022 • 17 tweets • 8 min read
1/17 I agree with this assessment. Nonetheless, since I am apparently a masochist, I geolocated all of the nuclear weapons storage sites active in Belarus during the 1980s.

I'm pretty sure there were 22 of them, though I am open to corrections. 2/17 First, a few notes: In Russian and Soviet service, nuclear weapons (except those attached to deployed strategic missiles) are under the control of the 12th Main/Chief Directorate (12 GUMO), a separate branch of the military directly subordinate to the Ministry of Defense. Image
Jan 14, 2022 • 4 tweets • 2 min read
Yesterday's launch was rail-mobile. Presumably the KN-23-like missile they tested last September? Oh, that's interesting. They uncoupled the locomotive prior to launch. So the 2-car set for the missiles is a self-contained unit and (similar to the Soviet RT-23) doesn't need to draw power from the locomotive.
Sep 29, 2021 • 12 tweets • 4 min read
I see the ghost of the R-27 has returned to haunt us again.

"Ampulization," referring to the fueling & hermetically sealing of a ballistic missile at the factory, was a Soviet innovation, developed by the Makeev bureau & first used in the R-27 SLBM. 1/12
2/12 For the Soviets, ampulization required the development of several technological advances. While no longer on the cutting edge, North Korea's potential use of ampulization has implications for where certain parts of the DPRK program are, technologically speaking.
Oct 10, 2020 • 12 tweets • 4 min read
Okay. I'm out of bed and have some milk and cereal, so let's start.

Fun fact: because those horses live, someone in North Korea starves. There is absolutely no reason to mount that scope on a rifle with that short of a barrel.
Sep 20, 2019 • 39 tweets • 16 min read
1/18 Okay. Now let's talk about what can be done to defend against this type of attack.

This is sort of pushing the limits of my knowledge, so please chime in if I miss something. 2/18 The methods for countering drones and cruise missiles can be broken into two broad categories:
Kinetic (guns, missiles, and lasers)
Electronic (jamming and spoofing)
Sep 19, 2019 • 14 tweets • 6 min read
New thread: Why did Abqaiq's air defenses fail?

First, updated maps of the air defense sites at Abqaiq. First one is April 2019 (the date of the image), the second is how forces were deployed as of this week.

This thread will by much more analysis, much less satellite imagery. Let's get some misconceptions out of the way:
-The Saudis are not incompetent
-Patriot is not useless
-The attackers were not merely "lucky"
-I am not actually air defense expert
Sep 18, 2019 • 10 tweets • 7 min read
You know who I feel sorry for in Saudi Arabia right now? The Air Defense Forces officer in charge of the short range air defenses at the Abqaiq oil facility. He'll be lucky to get out of this with his life.
1/7 On paper, the point air defenses at the Abqaiq oil processing facility are rather formidable... by 1995 standards, at least.

A battery of Shahine SAMs (French system from the early 1980's)

3 or 4 anti-aircraft gun sections, each with 2 twin 35mm cannons and a fire control unit
Aug 16, 2019 • 14 tweets • 7 min read
1/12 Continuing from the previous thread on Soviet nuclear turbojet research, I will now give a quick overview of Soviet nuclear ramjet research.

This thread is a bit longer, since the story is rather convoluted.

(Previous thread linked below) 2/ Soviet nuclear ramjet research can mostly be traced back to OKB-670, originally led by Mikhail Bondaryuk.

In the 1950's, OKB-670 focused on conventional ramjets for surface-to-air missiles and experimental intercontinental cruise missiles.
Aug 9, 2019 • 5 tweets • 2 min read
UPDATE: 5 Rosatom employees died due to the fire at Nenoksa, according to Interfax and RIA Novosti. Rosatom says they were working on "изотопных источников питания, разработанных для жидкостной реактивной установки" 1/2 interfax.ru/russia/672243 2/? That translates as "Isotope source power supplies, developed for a liquid reactive engine"

an изотопный источник is a sealed radiation source, so a capsule of radioactive material, such as Strontium-90, Cesium-137, Plutonium-238, etc.
May 10, 2019 • 14 tweets • 8 min read
1/ Was glad to help with this. Now that it’s out, I can give some explanations. I have the first nine tweets planned out. Then I’ll need to pause and write the rest

This thread might end up rather long. I apologize in advance. 2/ Missiles like Russia’s Iskander, China’s M20/DF-12, the US ATACMS, and the new North Korean Missile fly on depressed trajectories, never leaving the atmosphere and maneuvering throughout the whole duration of flight. They are sometimes called “quasi-ballistic” missiles.