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US 1102653Freedom to Build
Public domain since 1933

You can freely build on Robert Goddard's Early Design for Liquid-Fueled Rocket Engines

This patent expired in 1933. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.

Original assignee

Individual

Patent granted

1914

Expired

1933

Forward citations

59

What this patent covers

This patent describes a rocket apparatus designed to improve efficiency by using a combustion chamber and a nozzle to accelerate exhaust gases. It outlines a system where liquid fuel and an oxidizer are injected into a chamber to create controlled thrust. By focusing on the geometry of the combustion chamber and the expansion of gases, it established the fundamental architecture for modern liquid-propellant rockets. This was a significant shift from the solid-fuel rockets used for centuries, as it allowed for more controlled and sustained flight.

What is now free to use

All 0 claims of US 1102653 are in the public domain. Specifically:

    The 0 dependent claims add narrowing limitations and are also free.

    What is NOT covered

    Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

    • Does not cover modern guidance or navigation systems for rockets.

    • Does not cover multi-stage rocket designs or separation mechanisms.

    • Does not cover specific chemical compositions of modern high-performance rocket fuels.

    • Does not cover electronic ignition systems or computer-controlled thrust vectoring.

    Who is building on this today

    Modern aerospace giants like SpaceX, Blue Origin, and United Launch Alliance continue to refine the liquid-propellant combustion cycles pioneered by these early designs. These companies have scaled the basic principles of fluid injection and nozzle expansion to achieve orbital flight.

    Products built on expired version of this technology

    Liquid-fueled rocket engines

    SpaceX Merlin engines

    Blue Origin BE-4 engines

    Early sounding rockets

    How to cite this patent in your documentation

    Individual. US Patent 1102653. Rocket apparatus.. Granted 1914, expired 1933. Now in the public domain.

    Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

    PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.

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