Spacecraft Membrane Packing Method for Uniform Tensioning

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Solution Overview

Problem

Existing methods for packing and unpacking spacecraft membranes, particularly square membranes made of triangular segments, face issues such as uneven tensile stress distribution, crease formation, and inefficient unpacking processes, which hinder effective operation and increase mass and complexity in spacecraft systems.

Innovation Solution

A method involving packing a spacecraft membrane into a transverse package and then a longitudinal package, with freely accessible corners for controlled unpacking using extendable masts, allowing for uniform tensioning and reduced mass by minimizing the need for multiple spool bodies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If spacecraft membranes are made up from four triangular partial membranes, then the width limitation of spool bodies is avoided, but uneven tensile stress distribution and crease formation occur

Engineering Contradiction:

Improvemembrane widthVSAvoidtensile stress distribution

Core Design Contradiction:

Area of moving objectVSManufacturing precision

Solution Approach 1:

The membrane is divided into four triangular partial membranes that are joined together, allowing the overall membrane width to exceed spool body limitations while maintaining manageable packaging dimensions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a central reinforcement element that creates an asymmetric stress distribution pattern, concentrating tensile strength at the center where stress is highest during deployment, thereby compensating for the uneven stress distribution inherent in triangular segment configurations

Inventive Principle:

Principle #4Asymmetry

2Area of moving object

If multiple spool bodies are used to avoid width limitations, then membrane width is increased, but device complexity and mass increase

Engineering Contradiction:

Improvemembrane widthVSAvoidnumber of spool bodies

Core Design Contradiction:

Area of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple spool bodies into a single spool body by using a central reinforcement element that consolidates the winding architecture, thereby reducing device complexity and mass while still achieving the required membrane width

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a two-dimensional spool body arrangement to a three-dimensional central reinforcement structure, allowing the membrane to achieve greater width without proportionally increasing the number of spool bodies

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Strength

If weights are attached to tensioning ropes for unpacking, then the solar sail membranes can be tensioned, but vibrations decay slowly and operation is delayed

Engineering Contradiction:

Improvemembrane tensionVSAvoidvibration decay time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The patent introduces a central reinforcement element as an intermediary structure that provides a rigid framework for membrane attachment, thereby reducing membrane vibrations more effectively than weight-only tensioning systems

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses a composite structure combining the central reinforcement element with the membrane material, creating a hybrid system that provides both tensioning capability and vibration damping, reducing the time required for vibration decay

Inventive Principle:

Principle #40Composite materials

4Ease of operation

If spacecraft rotation is used to centrifuge out membranes, then unpacking is achieved, but high energy effort is required for realignment

Engineering Contradiction:

Improveunpacking mechanismVSAvoidenergy for realignment

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent employs a self-unwinding mechanism where the membrane automatically deploys from the spool body using stored elastic energy or gravitational forces, eliminating the need for energy-intensive rotation and realignment operations

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10934024B2Method for packing and unpacking a spacecraft membrane, spacecraft membrane package and spacecraft membrane handling unit

Publication Date: 2021.03.02 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V

AI summary

In a method for packing a spacecraft membrane (1) which in a plane of extension comprises a longitudinal axis between opposite longitudinal corners (4) and a transverse axis running transverse to the longitudinal axis and through transverse corners into a spacecraft membrane package, two packing steps are executed: In a first packing step, the spacecraft membrane (1) is packed into a transverse package (9) along the transverse axis. In a second packing step, the transverse package (9) is packed into a longitudinal package along a longitudinal axis. The packing of the spacecraft membrane (1) in the first packing step comprises a packing of material of the spacecraft membrane (1) from or on both sides of the longitudinal axis. In the first packing step, the spacecraft membrane (1) is packed in such a way that in the created transverse package (9) the transverse corners are freely accessible. In the second packing step, the transverse package (9) is packed in such a way that in the created longitudinal package the longitudinal corners (4) are freely accessible. The longitudinal package is unpacked by pulling on the longitudinal corners (4). Subsequently, the transverse package (9) is unpacked by pulling on the transverse corners.