07 August 2013


A USG Dept of War's several hundreds of billion dollar fast U235  fission  project (2013 USD) was tried for the first time, in 1945, today, never tested before.  It worked.  Not really as much a surprise as the (Pu implosion) Trininty test in July, but damn, not testing that beast before deployment, wow, not very ISO-9001 to deploy before test.  Despite all the amazing lab work, the chicago hemmoroids, etc.
Can you imagine if it didn't work?   But then, it had to work, it was just physics getting worked out.  Its like cutting an apple stem and expecting it not to fall.

The unfortunate side effect was showing that it was possible.  Although, granted, a review of the prewar physics would have led to it in a decade (IMHO).

Boom, no hiroshima.  Boomboomboomboom no Dresden.  Don't say we know its coming because it will compromise our codebreaking, Coventry sacrificed.

Bigbadaboom no World Trade Center.


I was recently looking into how the V2 guidance worked, I was impressed.  (1940's servos!!!)
They built them in factories built under mountains.  (sound
familiar?)  A V2 is a single stage rocket somewhat like the scud.
It carried explosive that *had to withstand the heat of reentry from
50 mi up*.  I never knew that.  Pretty amazing!

vonBraun was surprised that the anglos hadn't utilized Robert Goddard's work, which was VB's practical foundation.

RG's first rocket was clueless, you cannot stabilize a rocket by having the nozzle above the mass.  though you'd think so, you can't.
But he's so happy standing next to it.  He was awesome.

Bottle rockets use the *aerodynamics* of the stick to guide motor.
Once hit the Pru from a brownstone in Boston.  Don't ask.

The V2 had gyros, servos, and controlled both aeilerons (useful when flying in air) and exhaust vanes (useful when starting out before aeilerons would work, and when above the air).  Cf Estes rockets which use metal rods for initial guidance and then aft fins.

I mention this off-topic crap since some of you might appreciate 1940s
control tech.  Else hit 'delete' or 'next'

You start by using gas tank pressure to force peroxide into a gas generator.  This drives your pumps to force huge amounts of fuel into a chamber already lit (but not particularly thrusty) with a simple electric pyro.  Rocket chambers are 100 atmospheres.  that means the pumps must achiever greater than that injection pressure.  That was the key insignt for me.  LOL.

A gas otto engine compression is 8 atm.  Diesels maybe 12?

A brisant explosive is maybe 100K to 1M atmospheres, for a very short time.

Gas in your gut is a small percentage of atmospheric.  But distention hurts!

(PS: Consider: Your BP is 150:100 mm Hg compared to 760 mm Hg of the ocean of air above you.  )

clearly I'm raving.


VT You aim the direction (azimuth), set the range (ie fuel amount), that's the total steering you have.

Whee, london.


Sorry, rockets are OT, except for nuclear rockets, which have the same control issues, yawn.  And heavy.

And aren't terribly popular for near earth games.   Nukes do power deepspace probes (Cassini) and various modern robogeologists on Mars.  Brrrr, Martian winter so cold, light so dim.
My plutonium heart beats strong.  I drill rocks, you keep me busy, ok?