some reason I never built an Honest John rocket model when I was
a kid. I always liked the design and the look of the nose cone.
Both Estes and Centuri made versions of the Honest John. Intentionally
or not, there was an advertisement for the Centuri Honest John model
on the page opposite of the past part of the article in this September
1968 edition of American Aircraft Modeler, from which this page
(begins on pp 40) was scanned.
Scale data, for use in model rocket competition, on the Army's first
unguided artillery rocket.
by G. Harry Stein
This information on the U. S. Army's Honest John M-31 artillery
rocket provides astromodelers with scale substantiation data required
under U. S. Model Rocket Sporting Code, 1967 Edition. It enables
use of scale model Honest John kits by both Estes Industries, Inc.
(Kit K-27) and Centuri Engineering Co. (Kit KC-25) for competition.
The Estes H-J kit is to a scale of 1:23.56; the Centuri H-J kit
is to a scale of 1:25.33. The basic dimensional data on the M-6
(X202-E2) rocket engine can also be utilized for scale models of
those NASA rocketsondes using the M-6 - EXOS, Jason, Javelin, etc.
Author's Honest John is very colorful with fluorescent red-orange,
white and black. It has held U. S. Class 2 Scale Altitude record
and won NARAM-6 and 7 scale events.
H-J development round No. 1236F-M173 on the fixed-development
launcher at White Sands Proving Grounds, New Mexico. Upper left
fin is all black, other fins are white.
The honest John M-31 was the U. S. Army's first surface-to-surface
unguided rocket intended for use as a long-range artillery weapon.
It consists of a nuclear or high-explosive warhead mated to a large
solid-propellant rocket motor. It is an unguided rocket depending
for stability in flight on four large fins. Its trajectory is pre-determined
by the azimuth and elevation of its 25-foot launching rail which
is mounted on a truck for mobility. Eight small solid-propellant
spin rockets located in four shrouds behind the warhead section
in the nose are triggered by a mechanical trip at the end of the
launching rail and impart a slow roll to the missile in flight to
average-out fin and thrust misalignments in order to improve accuracy.
Honest John is a large artillery rocket capable of delivering
a 2000-pound warhead at distances up to 15 miles. It is now considered
obsolete, having been replaced by the smaller Little John rocket
and the Lance rocket.
Development history: The Honest John's
M-6 (X202-E2) solid propellant motor was originally developed under
the Bumblebee Program of the Applied Physics Laboratory of John
Hopkins University under contract to the U. S. Navy Bureau of Ordnance
(BuOrd). It was intended to be used as the rocket booster for the
ramjet-propelled XSAM-N-6 Talos ship-to-air antiaircraft missile,
but was later replaced in this use by an improved solid propellant
booster of larger diameter and shorter length.
U. S. Army Ordnance Corps carried out some preliminary experiments
at White Sands Proving Ground, New Mexico, mating solid-propellant
JATO (Jet-Assisted Take-Off) rockets to inert warheads and stabilizing
fins to investigate the possibilities of creating an inexpensive
battlefield artillery rocket for close fire support. The successful
completion of these experiments led to the Honest John in which
the available M-6 (X202-E2) solid propellant ex-Talos booster 23
inches in diameter was mated to the 30-inch diameter special warhead
available from the Sandia Corporation's Special Weapons Laboratory.
first Honest John was launched from the Army Launch Area #1 at White
Sands Proving Ground on June 30, 1951. The author was present, standing
on the roof of a truck 1000 yards due west at Uncle Station. The
"H-J," as the missile came to be known at White Sands, surprised
nearly everyone with its exceedingly high noise level that was much
greater than the German A-4 rockets then being flown at White Sands.
It was the first time this booster, the M-6, had been fired at White
Sands, previous flight tests in the Bumblebee Program having been
conducted at the Naval Ordnance Test Station, China Lake, California.
Full mass production of the Honest John was started in 1952.
Douglas Aircraft Company was the prime contractor with Radford Arsenal
manufacturing the M-6 CX202-E2) rocket motor. At the time, the M-6
(X202-E2) motor was the largest production solid propellant motor
in existence in the free world.
From 1952 through 1957,
hundreds of Honest John rounds were launched at White Sands Proving
Grounds for various purposes. Initially, launchings were made to
determine the battlefield range tables - the trajectories followed
by the H-J as a function of launcher elevation, wind velocities,
Early firings were made from trussed-rail-type
launchers in the Army Launch Area #1 at White Sands, and launchings
were usually made two at a time with three minutes between firings.
Later, firings were made from the tactical mobile launch trucks
with their 25-foot launch rails. Test firings were also made from
shortened truck rails.
One modification of the H-J was the
"Father John" missile, basically an H-J with additional small solid
propellant motors clustered around it. Only a few Father John missiles
Considerable trouble was experienced with the
quenching of the huge cloud of dust and smoke kicked up by the launching
of an H-J. The tremendous jet blast from the missile created a thick
cloud that rose as high as 1000 feet in the air. Such a cloud would
reveal an H-J launch site to the enemy at once and probably result
in making said launch site a prime target for enemy artillery at
once. Naturally, the technique of preventing such a cloud is highly
By 1957, the Honest John M-31 was operational
in the hands of special rocket artillery troops and had been deployed
The M-6 (X202-E2) rocket motor: The M-6 (X202-E2)
solid propellant rocket motor is made by Radford Arsenal. It uses
a modern composite solid propellant of classified nature. Its length
is 184.9 inches with a diameter of 23.0 inches. Launch weight is
3783 pounds for the M-6 alone, less fins and launch lugs. The M-6
(X202-E2) produces 84,000 pounds of thrust for 5.20 seconds from
2050 pounds of propellant, resulting in a calculated total impulse
of 213 pound-seconds-per-pound. (The original M-6 produced 105,000
lbs. of thrust for 4 seconds and was known as "JATO 4-D5- 105,000.")
The basic M-6 CX202-E2) rocket motor is also used as the
lower stage in several of the ARGO-series of rocketsondes such as
the EXOS and Javelin, both of these vehicles also using the basic
Honest John fin assemblies.
Color schemes: Few rockets can
boast the varied number of color schemes used on the Honest John.
This is because of the fact that so many different rounds were used
for White Sands firings, where separate vehicles were often painted
differently to provide identification on film records. In addition,
different White Sands paint patterns were applied to aid tracking
or data reduction for special test rounds where, for example, roll
rate or attitude had to be accurately determined from phototheodolite
R&D flights of the Honest John at White Sands were painted flat
white overall. In nearly all cases, one fin and aft 34 inches of
the motor casing were painted flat black as follows, the missile
resting on the launch rail and being viewed from the rear: Upper
left-hand fin painted black on both sides; the aft 34 inches of
the motor casing painted black between the two left-hand fins. The
black-and-white checkerboard roll pattern forward and aft of the
nose ogive base was, on all rounds of this paint scheme, identical,
the aft portion being alternately white and black in circumferential
quadrants as shown in the photos (two black quadrants and two white
quadrants) while the forward portion of the pattern is broken into
eight circumferential sectors and positioned with respect to the
aft pattern as shown.
Rounds were also flown at White Sands
painted fluorescent red-orange overall with blacked fins as per
above, no blacked aft motor quadrants, but blacked trailing edges
of all fins. Some of these had two spiral roll pattern bands wrapped
halfway around between the forward and aft motor bands. Other fluorescent
red-orange rounds had white ogives and transitions 105 inches back
from the nose tip with blacked fins as per above.
rounds launched at Fort Carson, Colorado and Aberdeen Proving Ground,
Maryland, were flat olive drab overall, sometimes with white serial
numbering, sometimes with black serial numbering.
on the white-and-black White Sands rounds was usually confined to
the warhead serial number painted lengthwise on the ogive and consisting
of the numbers "1236F-" followed by the serial number of the round
such as "M585" or "M521". The word "TOP" in black appeared just
forward of the forward launch lug. Sometimes the serial number of
the motor and the weights, CG location, and other data was stenciled
in black in 3-inch and I-inch letters on the side of the motor casing.
Data sources: This information on the U. S. Army Honest
John M-31 rocket was obtained from the following sources:
- Dimensions of the missile: From personal measurements made
by the author on the Honest John M-31 displayed at the White
Sands Missile Range. Measurements made June 2, 1957.
- From fact sheets obtained at the Public Information Office,
WSMR, in 1957 and June 23, 1966.
From NASA Technical Note
0-219 dated December, 1959 describing the EXOS rocketsonde and
giving dimensions and weights of the M-6 (X202-E2) rocket motor
as well as basic performance.
- From "Sounding Rocket Study Summary Report No. AST/elR-13337,"
NASA Wallops Station, dated 18 April 1961, describing and giving
weights and dimensions of the EXOS, Jason, Javelin and Strongarm
with M-6 boosters.
- From various U. S. Army Ordnance photos taken at White Sands
Missile Range and Aberdeen Proving Ground, and from various
photos taken by the author.
- The author wishes to express appreciation to the late William
Haggard and Gabriel Brilliante, Public Information Office, White
Sands Missile Range, and to Robert L. Krieger and Charles S.
James, NASA Wallops Station for providing the information used
<click for larger version>
Try out my
Scale Calculator for Model Airplane Plans
Posted August 7, 2010