Routine test launch

[jurph]

On 29 November, Russia launched an SS-25 ICBM from Plesetsk Cosmodrome to the Kura Test Range on the Kamchatka Peninsula. The launch was intended as a routine test of the SS-25's reliability. The missile's solid-fuel booster was at least 20 years old, but its single reentry vehicle hit its target as planned. The MosNews article includes a photo

Comments

[knile]

This seems bad/threatening. Saber-rattling? Just because they're bored? Actually routine?

[jurph]

Actually routine, and necessary. The ICBM era has only lasted about 50 years, and the first 30 of those were spent developing new boosters every ten years or so. The SS-25 became operational in 1985, so the oldest ones in their arsenal are 20 years old. Solid rockets are made of a rubbery fuel with particles of aluminum and oxidizer, and the aging properties of solid fuels are not well-characterized (nobody's ever had to store solid-fuel ICBMs for 20+ years before!). It's well known that if the fuel dries out and gets cracks, its surface area increases greatly, and the burn rate will be too high -- the pressure increases will "pop" the booster and it will explode in a manner similar to the Challenger accident. What is not well-known is how long it takes for the fuel to dry out, or whether the polymers in the fuel will migrate, leech into the pressure vessel walls, dry out, degrade, or break down into other polymers. You can do all the X-ray analysis of the boosters you want, but at the end of the day, you want to answer a simple

[dataknife]

so the SS-25 is not a MIRV type vehicle?

[jurph]

Nope -- under the START agreements it is limited to one reentry vehicle. The SS-25's ancestor, the SS-20, had three warheads in an unshrouded "clove-of-garlic" arrangement (it's easier to see here). I think the SS-20 was completely eliminated under SALT or SALT II, though.

It's all about deterrence and stability. A multiple-warhead missile is destabilizing because one warhead from the enemy kills N of your warheads when you have more eggs in each basket you are incentivized to "use 'em or lose 'em". Similarly, mobile missiles are stabilizing because the enemy can never guarantee that they'll be able to hit all of your mobile platforms at once. The most stable deterrent would be a small widely-spaced force made of single-RV mobile missiles.

[eeblet]

boo.