Slot Thrust Motor Cavities for Missile Attitude Control

Solution Overview

Problem

Current missile seeker systems face high costs and complexity due to the need for large angles of attack in tracking and endgame maneuvers, which are exacerbated by the volume and weight of conventional attitude control motors (ACMs) that occupy valuable space and increase the missile's airframe maneuver time constant, thereby limiting detection and tracking range requirements.

Innovation Solution

The implementation of a chemical plasma steering system that uses slot thrust motor cavities with chamfered openings to expel gas streams perpendicular or offset from the longitudinal axis, allowing for more efficient steering forces to be generated without the need for high-pressure containment of energetic reactants, thereby reducing the volume and weight requirements within the missile.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional attitude control motors (ACMs) are added ahead of and behind the missile center of gravity and center of pressure to reduce seeker look angle requirements, then the detection and tracking range requirements are reduced, but the flight performance of the missile is significantly affected due to the weight and volume of the ACMs

Engineering Contradiction:

Improveseeker look angle requirementsVSAvoidmissile weight

Core Design Contradiction:

Measurement precisionVSWeight of moving object

Solution Approach 1:

The invention extracts the high-pressure containment function from the attitude control system by using slot thrust motors that expel gas streams directly without requiring high-pressure containment of energetic reactants. This eliminates the heavy ACM components while maintaining the steering function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the conventional mechanical ACM system with a chemical plasma steering system that uses slot thrust motor cavities with chamfered openings to generate steering forces through controlled gas expulsion, eliminating the need for heavy mechanical actuators.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If conventional attitude control motors (ACMs) are added ahead of and behind the missile center of gravity and center of pressure to reduce seeker look angle requirements, then the detection and tracking range requirements are reduced, but the interior volume of the missile is consumed by the ACM components

Engineering Contradiction:

Improveseeker look angle requirementsVSAvoidmissile interior volume

Core Design Contradiction:

Measurement precisionVSVolume of moving object

Solution Approach 1:

The invention extracts the high-pressure containment function from the attitude control system by using slot thrust motors that expel gas streams directly without requiring high-pressure containment of energetic reactants. This eliminates the heavy ACM components while maintaining the steering function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The slot thrust motor cavities are integrated into the missile airframe structure itself, using the airframe walls as the containment structure for the energetic reactants, eliminating the need for separate voluminous ACM housings.

Inventive Principle:

Principle #30Flexible shells and thin films

3Measurement precision

If the missile airframe maneuver time constant is reduced to reduce detection range requirements, then the seeker system cost and complexity are reduced, but adding more ACMs to achieve this reduction significantly affects flight performance

Engineering Contradiction:

Improvedetection range requirementsVSAvoidseeker system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The invention replaces the conventional mechanical ACM system with a chemical plasma steering system that uses slot thrust motor cavities with chamfered openings to generate steering forces through controlled gas expulsion, eliminating the need for heavy mechanical actuators.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental operating parameters of the attitude control system by using low-pressure chemical reactions instead of high-pressure mechanical thrust, enabling faster response times and reduced maneuver time constants without the complexity of conventional ACM systems.

Inventive Principle:

Principle #35Parameter changes

4Adaptability or versatility

If conventional attitude control motors are used for flight maneuverability, then the missile can perform tracking and endgame maneuvers, but the ACM components are relatively heavy and compete for volume in the missile with other missile subsystems

Engineering Contradiction:

Improveflight maneuverabilityVSAvoidmissile volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The slot thrust motor cavities are integrated into the missile airframe structure itself, serving both as structural components and as the attitude control system, eliminating the need for separate voluminous ACM housings.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention extracts the high-pressure containment function from the attitude control system by using slot thrust motors that expel gas streams directly without requiring high-pressure containment of energetic reactants. This eliminates the heavy ACM components while maintaining the steering function.

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

This solution reduces the missile's airframe maneuver time constant, decreases the detection and tracking range requirements, and lowers the complexity and cost of seeker systems by allowing for more compact and lightweight designs, while maintaining effective maneuverability and hit-to-kill capabilities.

Implementation Method 1

igniting, simultaneously, the group of selected STMs, to detonate the ERC

Methodology Applied

Scientific EffectDetonation: Detonation

Implementation Method 2

expelling a stream of gas through the chamfered opening, in response to the detonation of the ERC

Methodology Applied

Scientific EffectGas expansion:

Implementation Method 3

expel a stream of gas in a gas-flow direction which is at least one of perpendicular to and offset from the longitudinal axis

Methodology Applied

Scientific EffectGas flow:

Implementation Method 4

The chamfered opening configured to expel a stream of a gas... to effectuate the amount of the steering force in a force direction which is at least one of opposite and offset from the gas-flow direction

Methodology Applied

Scientific EffectThrust:

Data Source

PatentUS10914559B1Missile, slot thrust attitude controller system, and method

Publication Date: 2021.02.09 LOCKHEED MARTIN CORP

AI summary

The embodiments disclosed include a system comprising a missile segment having a hollow body with an external surface conforming to an external surface of a portion of a missile body. The missile segment comprises a plurality of slot thrust motor (STM) cavities arranged in the hollow body. Each STM cavity being elongated in a first direction relative to a longitudinal axis of the missile body. Each STM cavity includes a chamfered opening at one end of the STM cavity coincident with the external surface of the hollow body. The chamfered opening configured to expel a stream of a gas in a gas-flow direction which is at least one of perpendicular to and offset from the longitudinal axis. The embodiments also include a missile and method for producing a steering force.