FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

NUMBER 10 179
The rocket project was approved by scientists.
For example, professor V.P. Vetchinkin, also one
of the closest pupils of N. Ye. Zhukovskiy, rated
highly the plan for the ramjet rocket. The support
of the ramjet rocket project by famous scientists
and foremost specialists in space technology allowed
this project to be put into effect. In 1937 a special
design department (headed by A. Ya. Shcherbakov)
of an aircraft plant started constructing ramjet
rockets. First, two ramjet models were designed
there for performing systematic investigations of
processes occurring in subsonic ramjets. To solve as
quickly as possible the basic problem, i.e., to prove
the possibility of creating a ramjet engine that
could develop a thrust exceeding the drag and impart
an acceleration to a vehicle, the P-3 rocket
was designed. This engine was to use solid grains
consisting of aluminum and magnesium powders
mixed with other substances. Cylindrical grains
with a through channel grains were placed in the
engine chamber.
Two types of grains were used in rockets. The
type manufactured by V.A. Abramov, a chemist
from the Moscow State University, consisted of
aluminium and magnesium powders bonded with
an organic filler. These grains were very stable and
burned uniformly in the engine chamber. The
heat-producing capability of the grain equalled
4200 kg-cal/kg. The rocket propellant charge contained
two grains of equal outer diameters, while
the diameters of the central perforations used for
introducing air into the combustion chamber from
the engine diffuser were different.
The grain was ignited with black powder which,
in turn, was ignited by means of a "stopin" fuse.
The total grain weight was 2.1 kg, burning time
being 8 sec.
Grains of another type were manufactured at the
D.I. Mendeleyev Moscow Chemical-Engineering Institute.
The work was directed by scientific staff
worker Dergunov. The grains were made by compressing
aluminium and magnesium powders under
high pressure. To intensify the burning process and
increase the engine thrust some oxidizer (potassium
chlorate) was added to those grains.
Three series of ramjet rockets (16 in all) were
manufactured for testing in flight.
The ramjet rocket of the first series had the following
specifications: the first stage weighed 3.8 kg
and the powder it contained weighed 1.4 kg, its
total impulse was 260 kg/sec, maximum thrust was
450 kg, average thrust was 118 kg. and powder
burning time was 2.24 sec; the ramjet rocket (second
stage) weighed 4.5 kg and its diameter was 121
mm; and total initial weight of the two-stage rocket
was 8.3 kg.
The next versions of the P-3 rockets had a somewhat
lighter structure compared with the rockets
of the first series.
While testing the P-3-2B rockets, powder rockets
of 82-mm missiles were used as the first stages, and
they had the following characteristics: total rocket
weight was 3.510 kg, the "H" ballistite powder
weight ranged from 1.050 to 1.079 kg, and the
powder-gas exhaust velocity was 1860 m/sec.
The first step of experimentation included investigations
of rockets in a wind tunnel. A score or
two of ramjet rocket blowdowns were made
throughout 1938 and at the beginning of 1939.
These investigations permitted a determination of
the rocket's coefficients of drag and selection of aerodynamic
brakes to achieve quick separation of the
first and the second stages. At the same time the
burning process in a ramjet chamber was studied.
In February 1939, flight tests of the ramjet began
at the airfield near the Planernaya Station, near
Moscow (Figures 1 and 2). The rocket was launched
vertically upwards using a launching device. During
the first tests the rocket take-off, stage separation,
and fuel ignition in a ramjet were developed. The
first successful flight, which took place on 5 March
1939, clearly showed the increase of the rocket
velocity due to the ramjet operation. Two rockets
tested on that day contained grains manufactured
by V.A. Abramov. These tests convincingly showed
a reliable operation of the whole system. It was
therefore decided to conduct official tests. To determine
precisely the flight velocities and rocket altitudes,
a group of astronomers was invited; they
used the methods of meteorite observations for this
purpose.
Official tests of the ramjet rocket, which took
place on 19 May 1939, were performed at night to
permit the rocket motion to be followed against the
background of the dark sky by watching the trace of
exhaust gases. The grain used in the rocket was
made at the D.I. Mendeleyev Chemical-Engineering
Institute. After the powder was ignited the rocket
left the launching device and went upward. The
first stage having separated, the second stage of the