
Soyuz MS-10 abort caused by sensor failure at booster separation - astdb
https://www.nasaspaceflight.com/2018/11/soyuz-ms-10-abort-sensor-failure-booster-separation/
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robin_reala
Interesting slide that shows the failed booster on the ground. I guess I’d
assumed they burnt up or at least crashed hard enough to completely destroy
themselves, but here it just looks a bit crumpled.

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hughes
I was also surprised by this. I would have expected it to explode on impact
just from the residual fuel in the booster's tanks.

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tehbeard
If I had to make an uneducated guess, probably a combination of the fuel
staying together during freefall rather than spreading through the tank and
some sort of inert gas (nitrogen?) pumped into the tank during ascent to keep
the internal pressure constant that also prevents ignition.

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sawjet
The soyuz strap-on boosters are constructed primarily of steel, as opposed to
aluminum, so they tend to survive the reentry and litho-braking better than
most people expect.

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avmich
> The soyuz strap-on boosters are constructed primarily of steel, as opposed
> to aluminum

I don't think it's the case. AFAIK, standard material for tanks construction -
and tanks in R-7 are load-bearing, unlike those in V-2 - is AMg-6, aluminum
alloy with magnesium as main addition. This alloy is chosen to keep
construction operations simple - using riveting - without too much risk of
fracturing the sheets of metal.

Engine is second biggest piece by mass in the booster. The chamber is made
from copper alloy - practically pure copper, with some small additions of
chromium (bronze BrH-08). Gas generator (which uses high test peroxide, 82%)
could be from steel (or some other high temperature resistant alloy), yes, but
it's a relatively small device. Same is for turbopumps.

For second stage it's often the case that it falls laying horizontally -
caused by aerodynamics. First stage boosters aren't that lengthy, comparing to
their width, but they can also fall sideways. This kind of landing is less
destructive, so some parts could survive the landing. First stage boosters
have the advantage of falling from lesser heights and having smaller initial
speed, so they have little problems with aerodynamic drag - way less heat to
survive.

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village-idiot
That explains why their boosters fall away in such a beautiful cross pattern,
they push the nose of the booster away from the core while the booster is
still burning.

