FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

52 SMITHSONIAN ANNALS OF FLIGHT
FIGURE 4.—Equipment for launching the Damblanc self-propelled variable-inclination rockets
(1939), and (right) more compact and simpler launching equipment for smaller diameter rockets
(the man in the photo is Damblanc's faithful assistant Maillard).
variations of the incandescent part of the flame.
Figure 3 shows frames from the film of a bench
test, on which can be seen the amplitude of sound
intensity and displacement of the recording pendulum.
On film I could observe that the vertical
flame progression had a remarkably sharp outline.
Our recordings were made by means of a camera
provided with a sound-recording device. Two
dynamic loudspeakers were interconnected. One,
placed near the rocket, served as a microphone
while the other, in front of the recorder, was used
as the receiver. In this way, I was able to coordinate
temperature and sound recordings. The
receiver-recorder was equipped with a device to
translate sound into light beams and to synchronously
record it on the photographic film.
The Launching Apparatus
The variable-inclination apparatus shown in
Figure 4 (left) I designed, built, and experimented
with as early as 1937. Thanks to these experiments
I could, in 1939, proceed succesfully to the launching
of my largest rockets (133-mm diameter) with
several automatically separable stages. For launching
smaller rockets, I used the simpler and more
compact apparatus shown in Figure 4 (right).
Rockets Tested, 1935-1939
Thanks to my carefully preserved files, the following
list may be given:
1. Two-stage 35.5-mm-diameter rockets. The first
stage was of steel, the second of magnesium, called
Metal Mx or "Electron," which represented at that
time the summit of metallurgical technique. Weight
of illuminating flare without parachute, 500 g;
firing angle, 90° and altitude as measured by
theodolite, 2,150 m, corresponding to a range of
6,325 m.
2. Rocket of the same diameter but, for the first
time with both stages made of magnesium. The
altitude reached exceeded the one for the previous
rocket but could not be measured because of cloudy
weather. All these tests were officially certified. This
rocket, very light and extremely easy to handle,
was tested on 24 October 1939, and was intended
to be mass-produced in several thousand units.
The same was true for the rocket of 72 mm
diameter tested at the same time. Its first stage
was of duralumin and the second, of Metal Mi
(Electron)—a great novelty at the time. This rocket
could carry an illuminating flare weighing 10 kg
up to an altitude of 500 m. Obviously, on the
eve of the Second World War, the practical applications
were subordinated to combat requirements.
3. Magnesium-alloy (Mx) rocket of 88-mm diameter
and a total length of 2.20 m. It had three
stages and triangular stabilization fins. Figure 5
shows this as well as a two-stage, 55-mm-diameter
rocket with different stabilization tail planes for
each stage. These were successfully launched on