Missile Stage Jettison Control via Secondary Flight Computer

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Solution Overview

Problem

Multi-stage surface-launched missiles face challenges in achieving long ranges while minimizing debris impact on friendly troops and assets, as existing solutions either consume significant payload weight for controlled landing hardware or degrade range performance due to energy compromises.

Innovation Solution

A multi-stage missile design featuring an upper stage with a primary flight computer and at least one lower stage with a secondary flight computer, where the secondary computer controls the jettisoned lower stage to glide aerodynamically to a safe landing zone after propellant depletion, rather than falling ballistically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If multi-stage missile design is used to achieve greater range, then range capability is improved, but debris from jettisoned stages falls on friendly troops and assets causing harm

Engineering Contradiction:
Improverange capabilityVSAvoiddebris impact on friendly troops
Core Design Contradiction:
Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful ballistic trajectory of jettisoned stages into a beneficial controlled glide path. By equipping lower stages with secondary flight computers and aerodynamic control surfaces, the previously harmful uncontrolled debris fall is transformed into a controlled descent to safe zones, eliminating the harm while preserving the multi-stage range extension benefit

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the flight parameters of jettisoned stages from uncontrolled ballistic motion to controlled aerodynamic glide. This is achieved by activating control surfaces and using flight computers to adjust trajectory parameters, allowing the stages to glide to predetermined safe zones rather than falling ballistically on friendly forces

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If controlled landing systems are added to jettisoned stages to prevent debris impact, then safety is improved, but significant payload weight is consumed by the hardware

Engineering Contradiction:
Improvedebris impact preventionVSAvoidpayload weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent treats the secondary flight computer and control surfaces on lower stages as disposable components. These systems are activated only during the brief period after stage separation to guide the spent stage to a safe zone, then discarded. This approach provides the necessary safety function without requiring heavy, reusable controlled landing hardware

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The jettisoned lower stages guide themselves to safe zones using their own remaining aerodynamic surfaces and onboard secondary flight computers. This self-service capability eliminates the need for external recovery systems or heavy payload-mounted landing gear, achieving safety without significant weight penalty

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If flight path is tailored to control where jettisoned stages fall, then debris placement is improved, but range performance degrades due to energy consumption

Engineering Contradiction:
Improvedebris placement controlVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The lower stages autonomously control their own descent trajectories using secondary flight computers and aerodynamic surfaces after separation. This self-guided glide to safe zones eliminates the need for the upper stage to expend additional energy on complex trajectory adjustments, maintaining optimal range performance while achieving precise debris placement control

Inventive Principle:
Principle #25Self-service

4Object-affected harmful factors

If secondary flight computer is added to lower stage to control glide path, then safety is improved, but device complexity increases

Engineering Contradiction:
Improvesafe landing zone controlVSAvoidflight computer system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the flight control functionality by placing a secondary flight computer on each lower stage rather than a centralized system. This distributed architecture allows each stage to independently control its own separation and descent, simplifying the overall system design while achieving the safety function of controlled glide to safe zones

Inventive Principle:
Principle #1Segmentation

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 design allows for extended range capabilities while minimizing debris impact risks, maintaining mission performance by optimizing the flight paths of both the upper and lower stages without the need for heavy return or re-use systems.

Implementation Method 1

the at least one jettisoned lower stage glides aerodynamically to a predetermined safe landing zone

Methodology Applied
Scientific EffectAerodynamic glide: Aerofoil

Data Source

PatentEP4200578B1Safe booster jettison for tactical missiles
Publication Date: 2023.12.06 RAYTHEON CO
  • EP4200578B1 patent drawingFigure 1
  • EP4200578B1 patent drawingFigure 2
  • EP4200578B1 patent drawingFigure 3

AI summary

A missile including an upper stage and at least one lower stage is provided. The upper stage includes a primary flight computer configured to control a flight of the upper stage along a missile flight path such that, for example, it reaches a predetermined target. The lower stage is mounted to the upper stage and includes a propellant for initially propelling the upper stage along the missile flight path. The lower stage is configured to be jettisoned from the upper stage when the propellant is spent. The lower stage includes a secondary flight computer configured to receive data from the primary flight computer prior to the propellant of the lower stage being spent, and to control a flight of the lower stage along a jettisoned stage flight path of the jettisoned lower stage such that, for example, the jettisoned lower stage glides to a predetermined safe landing zone