9720 – PRO SERIES II DOORKNOB

Pro Series II Builder Kit

Almost 27 inches tall and powered by D, E and F engines, this
1:5.3 Scale Model is an impressive Sport and Scale model of the
sounding rocket manufactured from Lacrosse rocket motors for the
project Hardtack Nuclear Test Series.

DESCRIPTION

During the mid-1950’s, the public concerns over nuclear fallout
due to US and Russian testing was reaching a fevered pitch. To
that end, President Eisenhower announced to the US on August 22,
1958, the US would ban further nuclear testing on or before
October 31 of the same year. US scientists, wanting to gather as
much data as possible, responded with Hardtack Series of tests.
Scientists where interested in many scientific areas, but primary

interest lay in the effects of radioactivity from underwater and
above ground detonation.

The Hardtack Nuclear Testing Program consisted of 35 detonations
in the Pacific Proving Grounds during the period of April-August
1958. Scientists, at the time, were chiefly concerned about
damage to the ozone layer and possible effects of long-range
radioactive fallout and determined that scientific measurements
of the earth’s upper atmosphere (aeronomy) would help clarify
what, if any, damage had occurred.

Single and two stage Doorknob rockets were developed using
Lacrosse and Thiokol solid propellent motors and could launch an
instrument laden sounding rocket to approximately 50 miles in
altitude and capture radioactive data for analysis. Early results

of this upper atmosphere data suggested little to no damage to
the ozone layer was measured during the nuclear testing and water

detonations probably produced enough ozone to replace what
little might have been lost due to above ground testing.

The Estes 1:5.3 scale model Doorknob is big and impressive.
Simple to build and fun to fly, this kit will be big hit in both
the sport and scale rocket categories. This kit has two sets of
decals available for those who want to turn this scale model into

a sports model.

ADDITIONAL INFORMATION
Recommended Engines
F15-4, F15-6, E16-4
w/Engine Adapter (sold separately)- D12-3

Projected Max Altitude
1100 ft. (335 m)

Recovery System
18 in. (45.7 cm) Nylon Parachute

Length
26.9 in. (68.3 cm)

Diameter
3 in. (76 mm)

Estimated Weight
10 oz. (283.5 g)

Estimated Assembly Time
3-4 Hours (painting and glue drying time not included)

Age Recommendation
Estes Pro Series II rocket kits are recommended for boys and
girls ages 18+ with adult supervision for those under 18, and
rocketeers of all ages.