Early Rocket Research (1900–1920)Aerospace & Rocket Propulsion

Solid-Charge Auxiliary Rocket

US 1,102,653

Tapered exhaust tube, spin-producing charges, and gyroscopic camera support

Inventor(s)Robert H. Goddard

Grant Date1914-07-07

Filing Date1913-10-01

LocationWorcester, Massachusetts

US 1,102,653 describes a solid-explosive rocket for carrying photographic or other recording instruments to extreme heights. Its disclosed apparatus uses a long tapered exhaust tube, electrically fired backward-curved spin charges, a smaller auxiliary rocket fired from a forward tube after the main charge is substantially consumed, and a gyroscope-supported camera that does not rotate with the spinning head.

USPTO PDF

Engineering Analysis & Physical Principles

How It Works: Step-by-Step Mechanical & Physical Breakdown

The source solves four linked problems for a high-altitude recording rocket: turn explosive heat into useful exhaust motion, rotate the rocket before launch, restore spin in its smaller follow-on rocket, and keep the camera from spinning with the outer body. It uses solid explosive disks, not liquid oxygen or gasoline; it fires the smaller rocket from a tube rather than dropping an exhausted lower stage.

The Core Breakthrough Mechanism

Disks 12 burn in primary chamber 10 and discharge through tapered tube 11. Goddard specifies a slightly tapered truncated cone at least three times its longest diameter, chosen so expanding gases can complete combustion before leaving the tube. Electrical heating elements ignite the backward-curved charges in recesses 15, producing reaction torque and initial spin. After the primary explosive is substantially consumed, fuse 28 fires the reduced auxiliary rocket in tube 24. Its later curved-tube charges restore spin, while gyroscope 37 keeps the pivoted camera support from following the head's rotation.

Interactive Real-Time Physical Simulation

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INITIALIZING THREE.JS WEBGL SIMULATION...

FrankenSim Physics Core/Live Telemetry

Supersonic Isentropic de Laval Expansion & Thrust Kinetics

Exit Mach Number

4.14Mach[1]

Exhaust Velocity

1,657m/s[L/T]

Specific Impulse (Isp)

169.0s[T]

Thrust Force (F)

2,983N[ML/T²]

Optimum Ae/At

15.7ε*[1]

Chamber Pressure (Pc)350 psi

Nozzle Expansion Ratio (Ae/At)3.5 ratio

Flight Altitude18 mi

Energy · thermodynamics_transport

Chem. enthalpy

9,511,389 W

Exhaust KE

2,471,084 W

Heat leak

7,040,305 W

Interval ghosts

v_e1657.0 m/s · [1200, 2800]

Plume admitted

Plume from isentropic v_e = 1657 m/s, T_e = 2074 K.

Dated scenarios

Detailed Component Architecture

1Primary solid-charge chamber and tapered tube

Explosive disks burn in chamber 10 and exhaust through the long tapered tube 11.

Goddard prefers disks 12 with progressively increasing burn rates so chamber pressure remains constant at the pressure for which tube 11 is designed. The tube is a truncated cone of slight taper, at least three times its longest diameter. It gives gases room to expand and complete combustion before exit. In conservation-of-momentum terms, exhaust momentum produces the rocket reaction, $F = \dot{m} v_e$ ; the source does not state a supersonic nozzle or a measured exhaust velocity.

19th-C. Term: explosive materialModern: solid propellant charge

2Initial spin charges

Backward-curved radial recesses 15 use reaction from small explosive charges to rotate the complete rocket.

Charges 16 sit in substantially radial, backwardly curved tubes. Battery 19, key 20, wires 18, and embedded heating elements 17 ignite them simultaneously. Their reaction torque raises the rocket's angular speed before fuse 14 starts main propulsion. The engineering relation is $au = dL/dt$ : a torque changes angular momentum $L$ ; the patent's limitation is the specific curved-tube explosive arrangement, not a generic attitude-control system.

19th-C. Term: tubes or recessesModern: tangential spin thruster passages

3Firing tube and auxiliary rocket

A reduced secondary rocket is launched from firing tube 24 after substantial consumption of the primary charge.

Fuse 28 reaches from auxiliary charge 27 into the last primary disk 12. The condition matters: when the primary propelling charge is substantially exhausted, fuse 28 ignites and firing tube 24 acts as a gun. The smaller rocket has its own chamber 25, tapered tube 26, and disks 27. This is a projectile-from-a-tube arrangement, not a claimed interstage separation mechanism.

19th-C. Term: firing tubeModern: launch tube for an auxiliary rocket

4Spin restoration and camera orientation

Auxiliary charges restore rotation, while a three-phase-motor gyroscope resists rotation of the camera support.

When auxiliary explosive 27 has been consumed to a predetermined extent, its rapidly burning path lights charges 31 in curved recesses 30. In head 29, pivoted support 33 holds camera 34. Gyroscope 37 is the armature of a three-phase induction motor and is brought to speed through wires 41 and temporary contact wires 43. Angular-momentum conservation makes its axis resist a change of orientation, keeping support 33 from rotating with the spinning head.

19th-C. Term: apparatus headModern: instrument compartment

Interactive Mathematical Physics & Rigorous Mechanics

Governing Equations & Colorized Principles

Dual-coded visual mapping & live SI telemetry

Tsiolkovsky Velocity Increment & Supersonic de Laval Nozzle Expansion

Aerospace & Supersonic PropulsionClaim 1

Mathematical Governing Law

\htmlClass{eq-term eq-term-delta_v eq-term-sapphire}{\htmlData{var=delta_v}{\textcolor{#2563eb}{\Delta v}}} = \htmlClass{eq-term eq-term-isp eq-term-emerald}{\htmlData{var=isp}{\textcolor{#059669}{I_{\text{sp}}}}} \cdot \htmlClass{eq-term eq-term-g0 eq-term-amber}{\htmlData{var=g0}{\textcolor{#d97706}{g_0}}} \cdot \ln\left(\frac{\htmlClass{eq-term eq-term-m0 eq-term-cyan}{\htmlData{var=m0}{\textcolor{#0891b2}{m_0}}}}{\htmlClass{eq-term eq-term-mf eq-term-coral}{\htmlData{var=mf}{\textcolor{#ea580c}{m_f}}}}\right) \quad \text{and} \quad \htmlClass{eq-term eq-term-ve eq-term-crimson}{\htmlData{var=ve}{\textcolor{#dc2626}{v_e}}} = \sqrt{\frac{2\gamma}{\gamma - 1} R \textcolor{#dc2626}{T_c} \left[ 1 - \left(\frac{\htmlClass{eq-term eq-term-pe eq-term-amethyst}{\htmlData{var=pe}{\textcolor{#9333ea}{p_e}}}}{\textcolor{#0891b2}{p_c}}\right)^{\frac{\gamma-1}{\gamma}} \right]}

Terms:

Plain English DecoderHover or tap any highlighted phrase

The equals the times times the natural log of over , propelled by expanding from down to .

\Delta v

Velocity Increment

Total kinetic velocity change achieved by rocket propellant combustion

Meters / second (m/s)[L T^-1]

Determines orbital capability and altitude ceiling for spaceflight.

Physical Principle & Engineering Insight

The New York Times famously ridiculed Goddard in 1920, falsely claiming a rocket could not fly in the vacuum of space without air to 'push against.' Goddard proved that thrust is an internal momentum reaction ( $F = \dot{m} v_e$ ) requiring zero external atmosphere.

Historical Context: US 1155986 proved liquid propulsion, multi-stage rocketry, and supersonic de Laval expansion, laying the foundation for Apollo 11 and modern space exploration.

Energy conversion and exhaust reaction

aerospace

Mathematical Governing Law

{\htmlClass{eq-term eq-term-var_0_f eq-term-emerald}{\htmlData{var=var_0_f}{\textcolor{#059669}{F}}}} = \dot{{\htmlClass{eq-term eq-term-var_1_m eq-term-sapphire}{\htmlData{var=var_1_m}{\textcolor{#2563eb}{m}}}}} {\htmlClass{eq-term eq-term-var_2_v_e eq-term-amber}{\htmlData{var=var_2_v_e}{\textcolor{#d97706}{v_e}}}}

Terms:

Plain English DecoderHover or tap any highlighted phrase

In the physical operation of this mechanism, is determined by the action of scaled by . Goddard explicitly treats the fraction of explosive heat transformed into kinetic energy as decisive for velocity. The familiar momentum form says thrust follows mass-flow rate times exhaust velocity, but the source's actual hardware is a solid charge and long tapered tube, with proportions selected experimentally.

F

Mechanical Force Vector

Net dynamic vector force acting upon the mechanism

Newtons (N)[M L T^-2]

Governs mechanical force vector within energy conversion and exhaust reaction: Goddard explicitly treats the fraction of explosive heat transformed into kinetic energy as decisive for velocity. The familiar momentum form says thrust follows mass-flow rate tim...

Physical Principle & Engineering Insight

Goddard explicitly treats the fraction of explosive heat transformed into kinetic energy as decisive for velocity. The familiar momentum form says thrust follows mass-flow rate times exhaust velocity, but the source's actual hardware is a solid charge and long tapered tube, with proportions selected experimentally.

Rotational dynamics

aerospace

Mathematical Governing Law

{\htmlClass{eq-term eq-term-var_0_tau eq-term-emerald}{\htmlData{var=var_0_tau}{\textcolor{#059669}{\tau}}}} = d{\htmlClass{eq-term eq-term-var_1_l eq-term-sapphire}{\htmlData{var=var_1_l}{\textcolor{#2563eb}{L}}}}/d{\htmlClass{eq-term eq-term-var_2_t eq-term-amber}{\htmlData{var=var_2_t}{\textcolor{#d97706}{t}}}}

Terms:

Plain English DecoderHover or tap any highlighted phrase

In the physical operation of this mechanism, is determined by the action of scaled by . Backward-curved passages discharge gas so its reaction supplies a torque. The initial set is made before flight in frame 21; the auxiliary rocket later has separate passages and a timed ignition path to restore spin after atmospheric friction has reduced it.

\tau

Tau (τ)

Governing physical parameter in Rotational dynamics

SI Units[1]

Governs tau (τ) within rotational dynamics: Backward-curved passages discharge gas so its reaction supplies a torque. The initial set is made before flight in frame 21; the auxiliary rocket later has separate passages and a ...

Physical Principle & Engineering Insight

Backward-curved passages discharge gas so its reaction supplies a torque. The initial set is made before flight in frame 21; the auxiliary rocket later has separate passages and a timed ignition path to restore spin after atmospheric friction has reduced it.

Gyroscopic orientation

aerospace

Mathematical Governing Law

{\htmlClass{eq-term eq-term-var_0_l eq-term-emerald}{\htmlData{var=var_0_l}{\textcolor{#059669}{L}}}} = {\htmlClass{eq-term eq-term-var_1_i eq-term-sapphire}{\htmlData{var=var_1_i}{\textcolor{#2563eb}{I}}}}{\htmlClass{eq-term eq-term-var_2_omega eq-term-amber}{\htmlData{var=var_2_omega}{\textcolor{#d97706}{\omega}}}}

Terms:

Plain English DecoderHover or tap any highlighted phrase

In the physical operation of this mechanism, is determined by the action of scaled by . A spinning rotor has angular momentum. Goddard uses gyroscope 37 on pivoted support 33 so the support can resist sharing the head's rotation. The patent describes the practical high-speed drive as a three-phase induction motor rather than claiming modern inertial navigation.

L

Inductance / Length / Lift

Circuit inductance, characteristic length, or dynamic force

Henries (H) / Meters (m) / Newtons (N)[M L^2 T^-2 I^-2]

Governs inductance within gyroscopic orientation: A spinning rotor has angular momentum. Goddard uses gyroscope 37 on pivoted support 33 so the support can resist sharing the head's rotation. The patent describes the practical hig...

Physical Principle & Engineering Insight

A spinning rotor has angular momentum. Goddard uses gyroscope 37 on pivoted support 33 so the support can resist sharing the head's rotation. The patent describes the practical high-speed drive as a three-phase induction motor rather than claiming modern inertial navigation.

Interactive Schematic Sheet (Fig. 1)

Longitudinal view, partly in section, of the rocket apparatus as a whole. Source PDF p. 1.

1.00x

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Why It Still Matters

This 1914 document is an unusually complete early high-altitude instrument-rocket proposal: it connects exhaust-tube geometry, pre-launch spin, a follow-on smaller rocket, and a gyroscopically held camera. Its value is in those stated combinations and conditions, not in a retroactive claim that it disclosed liquid engines, de Laval nozzles, or modern stage separation.

Legal Claims Decoder (8 Numbered Claims)

Compare dense legalistic claims directly with decoded plain-English functional specifications.

Claim #1Independent Master Claim

1/8

Verbatim Historical Legal Text

“In a rocket apparatus, in combination, a primary rocket, comprising a combustion chamber and a firing tube, a secondary rocket mounted in said firing tube, and means for firing said secondary rocket when the explosive in the primary rocket is substantially consumed.”

Plain English Engineering Translation

Claim 1 combines a primary rocket with both a combustion chamber and a firing tube, a secondary rocket mounted in that tube, and a trigger that fires the secondary rocket when the primary explosive is substantially consumed. The timing condition and the tube-mounted secondary rocket are both required parts of this claim.

Key Protected Innovations:

primary rocketfiring tubesecondary rocketsubstantial-consumption firing condition

The Historical Bottleneck

The specification's stated bottleneck is reaching extreme heights with recording instruments while converting a larger fraction of a solid explosive charge's heat into the rocket's kinetic energy. It also treats spin and the direction of a carried camera as linked practical problems.

Why Prior Art Failed

•The source contrasts ordinary rockets that discharge combustion gases through a rear opening with the elongated tapered tube 11 used here.
•A spinning outer rocket would rotate a recording apparatus with it unless a separate support and restraint were provided.
•Atmospheric friction reduces the auxiliary rocket's rotation, so initial spin alone does not meet the stated operational goal.

The Breakthrough Insight

“Goddard joins a long, slightly tapered exhaust tube to solid-charge combustion; a pre-launch electrically fired spin system; a reduced auxiliary rocket fired when the main charge is substantially consumed; and a gyroscope-supported recording instrument. The exact claims divide those combinations into eight independently stated legal definitions.”

After the Grant

The printed specification does not document a patent dispute, later settlement, or a particular commercial outcome. This record therefore preserves the historical apparatus and avoids attributing later liquid-engine or interstage-separation claims to US 1,102,653.

Civilizational Impact

The source records an early attempt to make a high-altitude instrument rocket into a coordinated machine rather than a simple firework. Its technical record includes solid-charge exhaust expansion, staged follow-on flight from a firing tube, spin management, and gyroscopic instrument orientation.