50 | SCIENCE ILLUSTRATEDThe V-2 rocket is the first to travel faster than the speed of sound,
but at such a velocity, even the slightest instability could be disastrous.B
efore the V-2, no aircraft had ever
travelled faster than the speed of
sound (about 1,200 km/h). The
German rocket travels 4.5 times this
speed, putting heavy demands on its
aerodynamic stability.
One particular problem is its
descent towards the target. When the
V-2 rocket travels through the lower
layer of the atmosphere at a speed of
about 5,700 km/h, the air builds up ina bow wave, increases drag, and can
even cause the V-2 to explode.
The Germans do anything in their
power to develop a streamlined and
sturdy design. Four fins are curved into
a new, "brushed back" shape – like the
tail feather of an arrow – as
experiments in some of the world’s
largest wind tunnels show that this
will reduce turbulence and pressure at
supersonic speeds. The rocket’s skin isalso strengthened. Wind tunnel
experiments with heat sensors
show that the rocket’s surface
is heated to 805°C at supersonic
speeds, as friction increases.
Aerodynamics experts use the
knowledge to built the V-2 with
the ideal type of steel to
counteract break-ups.PROBLEM
#2
At the same time, von Braun and his colleagues have
corrected the worst errors and omissions of the rocket.
The engine has been improved, a brand new control
system has been installed, and even the aerodynamics
function at supersonic speeds. The weapon is ready to be
used in the war.DEATH FALLS FROM THE SKY IN LONDON
"Showers" of V-2 rockets carrying explosive charges of
about 1000kg each start to rain down over England in
September 1944. The rockets are launched from mobile
launch pads, striking only five minutes after lift-off.
The mother of all attacks strikes London on Saturday 25
November 1944, when a blinding flash lights up the
Woolworths department store without prior warning. One
split second later, a deafening explosion blows out all the
windows, making walls and ceilings vibrate. Customers and
staff never manage to escape, before the entire building
collapses in a cloud of rubble.
A total of 168 adults and children are killed and 123
people are wounded in the attack, which literally hits like a
devastating bolt from the blue. None of the victims realise
what is happening. The rocket travels faster than the speed
of sound and is not heard, before it strikes.
As the chief developer, von Braun of course knows that
the V-2 was developed to be a military super weapon, but
that was not what he wanted.Supersonic Speed Destroys Body
ROCKET FINS
COUNTERACT SOMERSAULTS
Vanes force the rocket's centre of
pressure back to the rear end,
preventing it from "falling over"
at high speeds.labourers are
killed, and the
bombing changes
how the Nazis will
continue their rocket
program in Germany.
Realising that the base in
Peenemünde is much too vulnerable,
Nazi leaders decide to move the rocket
production to a secret, underground site near the town of
Nordhausen, the Harz, with von Braun's approval. The
tunnels, which are the result of many years of mining, are
converted into a large-scale assembly plant, Mittelwerk,
which will produce 900 brand new missiles a month.
Watched by brutal SS guards, slave labourers from the
Dora-Mittelbau concentration camp work hard in the cold,
damp underground world of the mine to finish the assembly
plant. Around the clock, the tunnels echo with the sound of
pneumatic hammers and the screams of prisoners, who are
beaten because they are unable to remain on their feet.
The place is rumoured to be Hell on Earth, and around 100
dead bodies are sent to the crematorium every day due to
summary executions and exhaustion. With this horrifying
background, the Germans start to roll the first V-2 missiles
out of the mine around 1 January 1944.3 PROBLEMS FOR THE NAZISCLAUS LUNAU
SPACE ROCKETS