FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

144 SMITHSONIAN ANNALS OF FLIGHT
2 inches in diameter. They were clamped at the
top by a yoke, or framepiece, which supported the
motor and its cooling jacket, the turn-on valves that
could be operated electrically, and a cone-shaped
nosepiece containing a parachute. At the rear of the
rocket were four fixed vanes of sheet aluminum for
guidance in vertical flight.
The propellants were gasoline and liquid oxygen,
forced into the motor by gas pressure at approximately
300 psi. The oxygen pressure was produced
by partial evaporation. The gasoline was pressurized
by nitrogen supplied from an auxiliary tank.
The parachute mechanism was kept closed by the
pressure of nitrogen in the gasoline tank, and was
set to spring open when the pressure dropped at
the termination of firing. The motor was an aluminum
casting, 3 inches in outside diameter and 6
inches long, with walls i/2 inch thick. Loaded with
fuel, this first ARS rocket weighed 15 pounds. The
motor was designed to provide a thrust of 60
pounds, giving an expected acceleration of 3G at
launching.
The first static test of the rocket occurred on
12 November 1932, on a farm near Stockton, New
Jersey. 8 Members of the Society had hauled lumber
and built a small wooden launching rack (Figure 3),
equipped with a spring-operated measuring device.
In the test the motor burned satisfactorily for a
period of from 20 to 30 seconds, and provided the
expected 60 pounds maximum thrust.
During these ground tests, however, the rocket
was accidentally damaged, and as a consequence,
was never flight tested. Its fragility, and the difficulty
of getting all the parts to operate satisfactorily
at the right time—still a problem with rockets—
caused the members of the experimental group to
decide on a thorough reconstruction, of such a
radical nature as to constitute a new rocket.
This task was put in the capable hands of Bernard
Smith, a young member with considerable mechanical
aptitude, later Technical Director of the
Naval Weapons Laboratory at Dahlgren, Virginia.
Smith removed the superstructure containing the
parachute, the water jacket, and other items that
had proved to have little or no value. He clamped
the motor securely between the upper portion of the
two propellant tanks, substituted light balsa-wood
fins for the aluminum vanes, and rounded the forward
end of the rocket with a streamlined aluminum
bonnet containing a large inlet port for air
cooling. Smith's drawing of this rocket is shown in
Figure 4.
This rocket, known as ARS No. 2 (see Figure 5),
was shot from a temporary proving field at Marine
Park, Great Kills, Staten Island, New York, on
14 May 1933. 9 It reached an altitude of about 250
feet, after firing about two seconds, and was still
going well when the oxygen tank exploded, appar-..
ently as the result of a stuck safety valve. It had
been calculated that the rocket would reach an
altitude of about a mile, but of course the bursting
oxygen tank released the pressure, the motor ceased
functioning, and the rocket dropped into the water
of lower New York Bay, from which it was rescued
by rowboat.
In spite of the accident, the members of the Society's
Experimental Committee considered the shot
successful. It was the first liquid propellant rocket
Ml
FINS
FULL VIEW SECTION
-PRESSURE NIPPLE
-GASOLINE TANK
-DELIVERY PIPE
FICURE 4.—Design of ARS Rocket No. 2. From The Coming
of Age of Rocket Power (New York: Harper & Brothers,
1945) p. 124.