FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

NUMBER 10 135
FIGURE 2.—Model E rocket. From Oberth, Wege zur Raumschiffahrt, 1929.
hydrogen-oxygen engines in propellant ratios of
1:4 to 1:5 (instead of the stoichiometric ratio of 1:8)
and produce exhaust velocities up to 5,000 m/sec.
For the same reason, I proposed to add water to
the alcohol in the first stages, even though these
engines do not develop the high exhaust velocities
of hydrogen-oxygen engines. Water has since been
used in almost all engines burning alcohol. The
demand for specifically heavier fuels in the first
stages, even though they do not develop such high
exhaust velocities, and for lighter fuels with higher
exhaust velocities in upper stages, also resulted
from the mathematical formulas in my writings.
I tried to avoid static reinforcements by keeping the
tanks under a light overpressure internally. This
principle has been applied practically to the Atlas
booster by Karel J. Bossart, who developed it to
technical maturity. 10
Another proposal of mine which has found application
is the use of parachutes for landing rocket
vehicles.
Later on, I had proposed electricity for the steering
mechanism. For example, for the speed-control
system, I proposed that a mass should act against an
elastic resistance; its deflection would then be a
function of the acceleration. The mass was to act
in such a way on a potentiometer (a variable electric
resistor) that a current proportional to the acceleration
would be produced. When this current is
integrated, speed will be indicated. This instrument
can also be used to close the fuel valves automatically,
when the desired speed is reached.
The attitude of the rocket was to be controlled
by a gyroscope which caused the rudders to deflect
by electric control as soon as the gyroscope and
rocket axes were not parallel.
In my book I also proposed a centrifuge, with
an arm 35 meters long, to examine systematically
the resistance of man to high accelerations, to train
man at high accelerations, and to select among the
applicants for space travel those with the best
abilities.