Spacecraft Heat Exchanger Thruster for High-Isp Propulsion

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Solution Overview

Problem

Existing spacecraft propulsion systems face inefficiencies and complexities, such as high propellant mass requirements, low thrust levels, and operational complexities, particularly in combustion-based and electric propulsion systems, limiting their maneuverability and suitability for various space missions.

Innovation Solution

A non-combustive rocket propulsion system utilizing a heat exchanger that transfers heat from a working fluid to a propellant, expelling it through a nozzle to generate thrust, with the heat exchanger manufactured via additive manufacturing using refractory metals like niobium alloys, enabling high-temperature propellant heating without combustion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If combustion-based propulsion systems are used, then high thrust is achieved, but propellant mass requirement increases and specific impulse decreases

Engineering Contradiction:
ImprovethrustVSAvoidpropellant mass
Core Design Contradiction:
ForceVSQuantity of substance

Solution Approach 1:

The patent changes the thermal parameter of the propellant by heating it to high temperatures (above 1000°C) through heat transfer from a working fluid in a heat exchanger, rather than using combustion. This parameter change enables the propellant to achieve high specific impulse (above 400 seconds) while maintaining sufficient thrust, resolving the contradiction between thrust and propellant mass requirement

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the chemical combustion mechanism with a thermal heat transfer mechanism. Instead of combusting the propellant to generate thrust, the system uses a heat exchanger to transfer thermal energy from a working fluid to the propellant, then expels the heated propellant through a nozzle. This substitution eliminates the need for separate oxidizer systems and reduces propellant mass while maintaining thrust capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Weight of moving object

If cold gas propulsion systems are used, then system weight is reduced, but thrust level becomes insufficient for orbit-raising and deorbiting maneuvers

Engineering Contradiction:
Improvesystem weightVSAvoidthrust
Core Design Contradiction:
Weight of moving objectVSForce

Solution Approach 1:

The patent changes the temperature parameter of the propellant from cold gas temperatures to high temperatures (above 1000°C) through heat exchange with a working fluid. This parameter change increases the specific impulse to above 400 seconds and generates sufficient thrust for orbit-raising and deorbiting maneuvers, while the system remains lighter than combustion-based systems because it eliminates heavy combustion chambers, oxidizer tanks, and associated safety systems

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If electric propulsion systems are used, then specific impulse is increased, but thrust capability becomes insufficient for significant in-orbit maneuvers and electrical power requirements increase

Engineering Contradiction:
Improvespecific impulseVSAvoidthrust
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The patent changes the thermal state of the propellant by heating it to high temperatures (above 1000°C) using a heat exchanger system that can be powered by solar arrays or radioisotope thermal generators. This thermal parameter change enables the system to achieve specific impulse above 400 seconds comparable to electric propulsion, while generating much higher thrust levels suitable for orbit-raising and deorbiting maneuvers without requiring complex electrical power systems

Inventive Principle:
Principle #35Parameter changes

4Force

If combustion-based systems use multiplehypergolic propellants, then efficiency and thrust are increased, but system complexity and dry mass increase due to separate fluid systems

Engineering Contradiction:
ImprovethrustVSAvoidsystem complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the oxidizer component from the propulsion system entirely. Instead of using multiple hypergolic propellants (fuel and oxidizer) that require separate storage tanks, pumps, and mixing systems, the system uses a single propellant that is heated by a working fluid in a heat exchanger. This extraction of the oxidizer function simplifies the system architecture, reduces dry mass, and eliminates the complexity of managing multiple propellant systems while maintaining thrust capability through the heated propellant expansion in the nozzle

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves efficient thrust generation with reduced propellant mass and electrical power requirements, allowing for high delta-V maneuvers and operation in diverse orbital environments, including Low Earth Orbit, with improved thrust efficiency and reduced system complexity.

Implementation Method 1

the heat exchanger can transfer heat from a solar collector or other heat source to a propellant

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

the heat exchanger body may be configured to transfer heat from the working fluid to propellant in the propellant channels

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

The heated propellant can be expelled through a nozzle, producing thrust

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

The nozzle may be configured to expel the propellant

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 5

a solar collector may be configured to capture solar energy and heat the working fluid before it enters or after it exits the heat exchanger

Methodology Applied
Scientific EffectSolar energy absorption: Solar Energy

Implementation Method 6

a solar collector may be configured to capture solar energy

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 7

the heat exchanger may be constructed via an additive manufacturing process

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Data Source

PatentUS12521784B2Systems, devices, and methods for spacecraft propulsion with a heat exchanger
Publication Date: 2026.01.13 PORTAL SPACE SYSTEMS INC
  • US12521784B2 patent drawing
  • US12521784B2 patent drawing
  • US12521784B2 patent drawing

AI summary

The present disclosure relates to systems, devices, and methods for spacecraft propulsion. In an embodiment, the present disclosure relates to an apparatus comprising a heat exchanger body defining a plurality of propellant channels configured to contain a propellant, a central cavity configured to contain a working fluid and fluidically connected to a plurality of working fluid channels that extend along a radial dimension of the apparatus, and a nozzle fluidically connected to the plurality of propellant channels and configured to expel the propellant.