FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

48 SMITHSONIAN ANNALS OF FLIGHT
T, connected to an electric generator G. Although
the overall efficiency of conversion was certainly
well below 1 percent, for the high sponsoring officials
this device was more convincing than any
scientific chart or presentation.
Next the mechanically driven injection system
to be used in the engine of Figure 19 was tested in
an apparatus designed to permit the atomization
characteristics of nitromethane to be observed. It
was unfortunate that the otherwise excellent Bosch
injection pumps available at the time were designed
for Diesel oil and hence did not require any positive
lubrication. During a particularly long run there
was an explosion which made the thick pump walls
literally disappear under my very eyes. I missed that
day my chance of being inscribed on the roll of
victims of propellant research, escaping with relatively
few injuries; after a month in bed I could
walk again. Dr. Corelli, who was standing next to
me, was also slightly injured.
The cause of the explosion was attributed to the
removal, after a few minutes of operation, of the
lubricating oil film from the pump plunger, with
resulting seizure of its surface. The corresponding
hot spots acted as ignition sources for the closely
confined, high-pressure nitromethane. Indeed, it
was easy to reproduce the explosion under controlled
conditions. Because at the time no injection
systems with positive lubrication were available,
the high-pressure injection process for nitromethane
was judged too hazardous, and was abandoned. A
few years later Bosch produced such a positive
lubrication system for gasoline engines.
In the following years we designed other monopropellant
engines of different types. Let me only
mention a compressed-gas engine to be used in
underwater propulsion, utilizing the gases produced
in a nitro-methane-plus-water gas generator,
and a spark-ignition 4-stroke-cycle piston engine
to be operated by nitromethane vapor alone. This
lead to a series of interesting studies and experiments
on the possibility of a decomposition-flame
propagation in the vapor itself. But this reseach is
too far removed from rockets to allow more than
this passing mention.
I also would like to mention our renewed interest,
in those years, in bipropellant combinations,
and the interesting studies of Dr. Corelli on the
properties of tetronitromethane as an oxidizer. The
Fifth Volta Conference, of which my father was
president (see Figure 21), provided an opportunity
for many of the leaders in the story of high-speed
flight to meet. However, generally speaking, the
interest of the Italian sponsoring offices in rocketry
was at a dead end.
It was only after the war, in 1947, that I became
again involved in experiments on the applications
of nitromethane to rocket propulsion for the Direction
des £tudes et Fabrication d'Armements of the
French Ministry of Defense. It was there that I succeeded
in operating a rocket chamber of appreciable
dimensions and relatively small L*, using
inward radial injectors uniformly distributed on
the cylindrical wall of the chamber. After 1949 I
continued this work for some time in the United
States, with the authorization of the French authorities
and the collaboration of the Aerojet-General
Corporation, where outward radial injection from
a central pylon was also successfully tested. But
all this is modern rocket history and not part of my
father's pioneering activity in the field of Italian
rocketry—the subject of this presentation.*
NOTES
Under the title Rannie issledovaniya v oblasti raket i
raketnogo topliva v Italii, this paper appeared on pages 34-55
of Iz istorii astronavtiki i raketnoi tekhniki: Materialy XVIII
mezhdunarodnogo astronavticheskogo kongressa, Belgrad, 25-
29 Sentyavrya 1967 [From the History of Rockets and Astronautics:
Materials of the 18th International Astronautical
Congress, Belgrade, 25-29 September 1967], Moscow: Nauka,
1970.
1. General Crocco was 90 at the time of this presentation
and died the following 19 January 1968. See "Ex mundo
astronautico," Astronautica Acta, vol. 14, no. 6 (October 1969),
p. 689.—Ed.
2. Luigi Crocco, "Instruction and Research in Jet Propulsion,"
Journal of the American Rocket Society, no. 80, March
1950, pp. 32-43.
3. Gaetano Arturo Crocco, "Sulla possibilits della navigazione
extra atmosferica, Rendiconti Accademia nazionale del
Lincei (Rome), ser. 5, vol. 32, part 1, 1923, p. 461; "Possibilita
di superaviarione," Rendiconti Accademia nazionale del Lincei
(Rome), ser. 6, vol. 3, 1926, pp. 241, 363; "II proiettile a
reazione," Revista aeronautica, vol. 2, no. 3 (March 1926), pp.
1-4; "La Velocita degli aerei e la superaviarione," Revista
aeronautica, vol. 2, no. 9 (September 1926), pp. 3-52; "Un
paradosso del propulsore a reazione," Rendiconti Accademia
nazionale del Lincei (Rome), ser. 6, vol. 3, 1926, p. 370.
4. An interesting account by Theodore von Karman of
General Crocco's Presidency of the Fifth Volta Congress of
High Speed Flight in 1935 and von Kdrnran's meeting with
General Crocco's son is given in his The Wind and Beyond,
written with Lee Edson (Boston: Little, Brown and Company,
1967), pp. 216-23.—Ed.