52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference<BR> 19th
4 - 7 April 2011, Denver, Colorado
AIAA 2011-2023
Deployable Composite Booms for
Various Gossamer Space Structures
Marco Straubel∗ , Joachim Block † , Michael Sinapius‡ , and Christian Hühne§
DLR - German Aerospace Center, 38108 Braunschweig, GERMANY
Deployable structures are required to either enable orbit transfer of very large structure
or to make the orbit transfer of medium and small size structures more affordable. Hereby,
deployable booms are basic building blocks of such deployable structures. DLR is providing
a concept for deployable booms that utilize very thin CFRP material and which can be
stowed by coiling.
The given paper introduces the concept of the CFRP booms and discusses the problems
of their self deployment tendency. Furthermore, different mechanisms are presented that
are able to control the deployment. Tests under artificial zero-g environment have been
conducted to verify the applicability of the control concepts. Hence, the paper also gives
insight in objectives, setup and the results of the experiment as well as a final evaluation
of the concepts. Finally, an outlook on current and future projects that use the introduced
booms or equivalent systems is given.
Nomenclature
Abbreviations
AOCS
Attitude and Orbit Control System
RF
Radio Frequency
SAR
Synthetic Aperture Radar
I.
Introduction
eployable structures are necessary to realize large but weight-efficient space systems. DLR provides
D
a deployable gossamer mast that can be used either to realize simple 1D structures like long dipole
antennas and instrument booms or to setup 2D and 3D structures that use this mast as basic truss concept.
Gossamer structures are optimized for their intended task. Thus, they provide only the required amount
of stiffness. In combination with the usual large dimensions, a sophisticated dynamic behavior occurs.
Resonance frequencies far below 1 Hz and low damping coefficients are characteristic attributes of those
structures.
This paper shall enable a basic understanding of the concept and of the resulting challenges. A deployment
test series under weightlessness is presented and evaluated to show possible concepts of deployment control.
A.
State of the Art
The currently available deployment systems can be clustered basically in the following three groups: the
pantographic systems, the elastically deformed systems and the inflatable systems. Those three will be
introduced hereunder.
∗ Structures & Mechanisms Engineer, DLR Institute of Composite Structures and Adaptive Systems, Lilienthalplatz 7, 38108
Braunschweig, GERMANY, Member AIAA
† Program Architect Space, DLR Institute of Composite Structures and Adaptive Systems, Lilienthalplatz 7, 38108 Braunschweig, GERMANY
‡ Deputy Director of DLR Institute of Composite Structures and Adaptive Systems, Lilienthalplatz 7, 38108 Braunschweig,
GERMANY
§ Head of Composite Desin Department of DLR Institute of Composite Structures and Adaptive Systems, Lilienthalplatz 7,
38108 Braunschweig, GERMANY, Member AIAA
1 of 11
American
Institute
Aeronautics
Copyright © 2011 by the American Institute of Aeronautics and
Astronautics,
Inc. All of
rights
reserved. and Astronautics
(a) RadarSat II with deployed SAR
antenna and solar array (Courtesy
of Canadian Space Agency)
(b) CoilABLE boom (Courtesy of ATK)
(c) Quadrilateral reticulations in deployed (left) and
stowed (right) configuration (Courtesy of CSA Engineering Inc.1 )
(d) Inflatable mast(Courtesy of
EADS)
Figure 1. Deployment principles
1.
Pantographic Structures
Pantographic or manifold structures are made of stiff parts that are interconnected with hinges. The hinges
are in most cases spring driven and use a locking mechanism that fixes the hinge after reaching its final
position. The start of the deployment is commonly triggered by pyro-mechanical cutters. Motor actuated
mechanisms are only used if the deployment needs to be reversible or the deployment velocity has to be
controlled for technical reasons (e.g. requirement from AOCS (Attitude and Orbit Control System)). Figure 1(a) shows one classical application of such structures. Canada’s Radar Sat II uses one deployable radar
antennas and two unfurlable solar arrays.
2.
Elastically Deformed Systems
A well known and space proven system is the CoilABLE Boom from ATK (see Fig. 1(b)). The mast can
be stowed by twisting. As the boom is under pretension in its compressed state, the deployment needs
to be controlled by a rotating nut. Figure 1(c) shows another building block for deployable structures: In
combination with struts it can be used to design various 1D and 2D structures.1 Here the functionalities
hinge and hinge-driving spring are integrated into the structure to save mass and to reduce the complexity in
order to increase the reliability. Further benefits of this concept are the absence of friction affected bearings
and the resulting robustness against small distortions of the packed structure due to thermo-mechanical
effects.
3.
Inflatable Systems
Inflatable systems (see Fig. 1(d)) are characterized by a low material thicknesses and very low weight.
However, they need an inflation system that contains either gas storing cylinders or pyro-active gas generators
that have to be considered in the mass calculation. Moreover, if an inflatable structure needs to maintain
its stiffness over a longer time period, the gas inflation system needs to provide the pressure during the
entire service time or the structure needs to be rigidized after deployment. Different kinds of rigidization
have been investigated: The curing of a resin impregnated composite by UV-light,2 by implemented resistive
heaters3 or the rigidizing of an aluminum layer by stretching the material beyond its yielding point.4 All
rigidizing concepts have been tested and successfully verified. However, the curing of composites under
2 of 11
American Institute of Aeronautics and Astronautics
Table 1. Trade off between deployment types (++ very good ; + good ; o moderate ; - poor ; – very poor)
stiffness
mass
stowage volume
shape accuracy
controllability of deployment
flight heritage
Pantographic
Structures
++
o
o
++
++
++
Elastic Deformed
Structures
+
++
+
++
++
+
Inflatable
Structures
+
++
++
+
+
space conditions is a very inhomogeneous process that leads, therefore, to asymmetric curing without a
shape giving tool which can lead to unintended distortions of the cured structure.
4.
Trade-Off
Table 1 provides a ranking of the different deployment techniques with respect to characteristic parameters.
As shown in this table the appropriate deployment concept depends on the mission requirements. Stiffer
structures are heavier and need more stowage volume but provide a higher geometrical accuracy.
B.
Applications
Potential application for deployable structures are dipole antennas, array antennas, instrument booms, optical and antenna reflectors, sunshades, solar sails, solar arrays, and deorbiting systems. Four of these
applications will be introduced hereunder.
1.
Solar Sails
Solar sails are an alternative propellantless propulsion system utilizing the Sun´s radiation pressure. At
Sun-Earth distance a pressure of maximal 9.1µP a can be used to accelerate a spacecraft. As this pressure
is relatively small, the spacecraft needs to have a low mass-to-sail area ratio to generate a significant thrust.
DLR has demonstrated in 1999 how to deploy such a solar sail by use of the introduced booms. During an
on-ground demonstration a solar sail of 400m2 size has deployed autonomously from the center module (see
Fig. 2(a)).
(a) On-ground deployment demonstration of a 20m x 20m solar
sail(ESA contract, DLR delivered
booms and sails)
(b) 1:3 sub scale model of a deployable SAR antenna (model size 6m x
1.4m)
Figure 2. Exemplary Applications
3 of 11
American Institute of Aeronautics and Astronautics
(c) Inflatable de-orbit device
(Courtesy of TU Delft)
deployed
stowed
Figure 3. Boom cross section in deployed and
stowed configuration
2.
Figure 4. CFRP Boom wrapped on a foam core
Antennas
Space antennas for radio communication and radar surveillance have always been an application for deployment techniques. Most existing deployable antennas concepts consist of folded arrays-like manifold
structures. These structures were flown many times and have proven their reliability but have the disadvantage of a high mass. To evaluate the lightweight potential of deployable SAR (Synthetic Aperture Radar)
antennas, DLR and ESA decided to establish cooperation for research on this topic. Figure 2(b) shows the
result of this study. The mechanical part of a deployable SAR antenna has been developed. It contains 3
membranes for RF-functionality and one additional service membrane for harness and amplifiers. The four
membranes are tensioned by constant force springs that are attached to a frame made of two coilable booms
(see section II.C.3 for details on used boom concept) and two coiling hubs. The final design is characterized
by deployed dimensions of 18m x 4.3m x 0.3m, stoweded dimensions of 0.6m x 4.3m x 0.3m and a mass of
only 53kg. For further details on the concept please refer to5 .
3.
DeOrbiting
The increasing population of space debris is a problem that needs to be counteracted. Out-of-service satellites
as well as upper stages from launchers generate a risky environment for new satellites passing or sharing the
same orbit. One possibility to decrease the amount of debris is a passive deorbiting of space systems by using
the aerodynamic drag within lower earth orbits. Therefore, the very thin residual atmosphere is used to
generate a constant decelerating force. To use this effect, large surfaces need to be deployed to increase the
area-to-mass ratio which is also known as ballistic coefficient. Figure 2(c) shows a representative Aerobrakestructure designed by the Technical University of Delft in the Netherlands. Very light, deployable systems
can provide this function. However, depending on the structure to deorbit the time period of storage can
reach some years. Such stowage times are a challenge for most deployable systems and need to be respected
during design and material choice.
4.
Solar Arrays
Other well known applications for deployable structures are solar arrays for power generation in space.
Conventional systems use foldable rigid planes or thin carrier foils that are fixed at deployable frames.
II.
Boom Introduction
The rollable CFRP boom has been developed by DLR within the ESA funded solar sail study in the late
1990s.6 With respect to the above defined categories of deployable structures, the boom can be assigned a
member of the Elastically Deformed Systems.
4 of 11
American Institute of Aeronautics and Astronautics
150 mm
60 mm
110 mm
74 mm
Figure 5. True to scale comparison between former Solar Sail (left)
and current GOSSAMER-17 (right) booms
A.
Figure 6.
Simulation results of uncontrolled boom deployment under 0 g
(done by Sickinger, DLR8 )
Design & Functionality
The basic concept of the boom consists of a so called double-Ω shape of the cross section. It enables the
boom to be flattened without material damages. The upper sketch of Fig. 3 shows the cross section in its
deployed state and the lower sketch in its stowed configuration. Due to the flattening the bending stiffness in
one direction decreases significantly which enables the boom to be coiled like a long tape spring (see Fig. 4).
Here it has to be emphasized that the used composite material is completely cured during the manufacturing process. The necessary flexibility of the material is generated by the low material thickness of 0.1mm
which leads to outer fiber strains that can be carried by the used carbon fiber laminate.
The deployed cross section of the former solar sail boom is shown in Fig. 5. The boom has a height of
110mm and a width of 150mm. In flat configuration the height decreases to 0.2mm and the width increases
to 209mm. The specific weight depends on the needed stiffness. Currently available boom of this geometry
require 62g/m. To stabilize the very thin and tensioned material in the coiled state a central core is required.
For the current cross section dimensions and material the core radius shall not fall below 100mm.
However, the entire design is scalable. In combination with the various types of CFRP laminate setups,
the basic concept boom can be adapted to unique mission requirements like stiffness and available storage
volume. Exemplary, a true to scale cross section of the novel GOSSAMER-1a booms is co-displayed in Fig. 5.
B.
Deployment Behavior
The above used analogy towards tape spring is a good explanation for the deployment behavior as well.
As the booms were manufactured in their deployed shape, the state of lowest energy is the deployed one.
Simulations done by Sickinger8 and displayed in Fig. 6 show the expected deployment envelope of a pure
5.25m long CFRP boom. After the release of the coiled boom the deployment process can not be stopped
or even controlled. Furthermore, the autonomous unfolding is not focused in one direction and requires,
therefore, an appropriate free area for deployment.
C.
Deployment Control
To prevent such chaotic deployment and establish a reliable and predictable deployable mast, different
deployment control principles have been created that will be introduced hereunder.
1.
Electric Root Deployment
The basic idea of the electric root deployment is to wrap one or more booms around a motor driven core that is
located in the spacecraft. Like a cable winch the booms are deployed by the rotating central hub that extracts
the booms in a controlled and continuous manner from the module and guarantees a smooth deployment.
This concept has been developed by the German company INVENT within the first Solar Sail study. One
a GOSSAMER-1 is a 5m x 5m solar sail deployment technology demonstrator under DLR and ESA funding. It is one out of
three intended missions of the 3-step GOSSAMER-Roadmap.7 The launch is scheduled for 2014.
5 of 11
American Institute of Aeronautics and Astronautics
Polymer Bladder
Composite Boom
Velcro Stripes
Figure 7. Electric tip deployment mechanism
Figure 8. 14m inflatable boom specimen
advantage of this concept is the possibility to deploy more than one boom with one mechanism. Thus, the past
solar sail design includes a deployable cross like structure of four booms that are simultaneously deployed
from one central hub. This concept is very weight efficient but has one disadvantage: The deploymenttransition zone that is required by the boom to evolve its full cross section and stiffness, is located next to
the central core. Thus, the least stable part of the boom is located at the most loaded region, the boom
root. The collocation of highest load and lowest stiffness results in an increased sensitivity of the deploying
structure against bending moment introducing disturbances.
2.
Electric Tip Deployment
To counteract the above described collocation, the decision has been made to transfer the weak transition
zone from the root to the tip. This is realized by the design of the electric tip deployment mechanism shown
in Fig. 7. It contains a cylindrical part for storage of the coiled boom and is equipped with two wheels that
are driven by a battery supplied electric motor. In contrast to root deployment the mechanism detaches
oneself from the main module after activation of the motor. The partly deployed end of the boom - as seen
left hand in Fig. 7 - is fixed at the center module.
Compared to the previously introduced concept, a single mechanism deploys only a single boom. In
consequence, the specific weight per deployed boom is higher in case of deployment of multiple booms.
However, since the deployment mechanisms are jettisoned after deployment, the total mass of the deployed
structure is lower than of the one utilizing the root deployment principle. Thus, the electric tip deployment
will not be the preferable concept for common Earth orbits (space debris). However, it is the supreme
solution for deployment of solar sails where the ratio between sail area and mass is proportional to the
acceleration achieved by the solar radiation.
3.
Inflating Tip Deployment
The third concept realizes a completely different deployment principle and features no electric motors or
movable parts. It consists mainly of two basic elements that control the deployment. As is shown in Fig. 8
the boom is equipped with a Velcro layer on each side. During coiling the hook part of one boom side
locks into the loop part of the other boom side and prevents a self deployment of the packed mast. To yet
deploy the blocked boom, a gastight polymer bladder of only 12µm thickness is inserted into the hollow
boom already upon manufacturing. Once pressurized the bladder acts as pneumatic actuator that deploys
the boom by locally breaking the Velcro connections. Depending on the level of controllability the needed
inflation gas can be provided by conventional gas tanks in combination with controllable valves or special
gas generators that produce gas by decomposition of solid materials. Compared to the other two concepts
the inflating tip deployment requires the application and insertion of extra material to the booms which
increases the specific mass per length by around 20 % - 40 %. However, the needed mass and the complexity
of the deployment supporting device in the main module are reduced.
6 of 11
American Institute of Aeronautics and Astronautics
III.
Deployment Tests
A zero-g test campaign was performed in February 2009 in order to attest the necessity and to verify the
presented deployment control concepts. The entire experiment area of the test plane Airbus A300 ZERO-G,
operated by the French company NOVESPACE, has been allocated to test deployable booms of realistic size
under realistic conditions. During the flight the pilots are able to generate up to 22 seconds of weightlessness
flying a parabolic trajectory and adjusting the engines thrust. The flight schedule for the test day contains
a total number of 25 experiment parabolas that are grouped in sequences of each 5 parabolas and one initial
test-free zero-g phase to give the experimenters the chance to become familiar with the special environmental
conditions. Therefore, booms with up to 14m length were tested using the following concepts:
Concept I: Free deployment without any control system to verify the expected chaotic behavior
Concept II: Electric Tip Deployment
Concept III: Inflating Tip Deployment
A.
Experiment Objectives
The following objectives for the experiment were defined:
• Demonstrate chaotic boom deployment without deployment control concept
• Show directness of unfolding process using inflating tip deployment concept
• Test repeatability of deployment using inflating tip deployment concept by multiple use of the same
boom specimen
• Test controllability of inflating tip deployment by decrease or total stop of gas supply during deployment
process
• Show directness of uncoiling process by electric tip deployment concept
B.
Experiment Setup
The test of the concepts I and II were started manually by the experimenters. To deploy the inflatable masts a PC controlled test rack (see
Fig. 9) was designed which is able to provide the required pressure and
monitor significant indicators like differential pressure between inflation
tube and cabin, mass flow rate of the inflating gas and a vertical acceleration sensor to log the quality of weightlessness.
The 20m x 5m test area was used as shown in Fig. 10. The test
rack was placed in the right rear section. The left half of the cabin was
reserved for storage of coiled and deployed booms. Since a main intention
for the experiment was the verification of the deployment process, the
observability was guaranteed by a total number of eight video cameras
that recorded each deployment from different angles of view. In addition
to the records done by the test rack and the cameras, the aircraft was
9. Test rack for inflating
able to record data as well. In total 17 sensor channels were logged. The Figure
tip deployment
specimen boom during
test rack incl. cam0
coileded
booms
deployed booms
cam7
...
cam1
Figure 10. Test setup in A300 ZERO-G
7 of 11
American Institute of Aeronautics and Astronautics
Figure 11. Exemplary frame of generated evaluation record showing the deployment of a 14m inflatable boom
data includes information like acceleration in all three special directions,
cabin pressure, cabin temperature, altitude, etc. A special challenge was
the synchronization of the three asynchronous data sources. The test rack records its data using 60Hz, the
cameras have a frame rate of 30Hz and the aircraft board system monitors at 25Hz. Thus, a trigger point
had to be set to merge all the data. To synchronize the autonomous recording cameras to the test rack
several LEDs that were connected in series, were placed in the view fields of the cameras and controlled by
the test racks PC. The diodes were activated for one second by the rack at the start of each experiment.
After the flight these trigger events were used to synchronize the rack and camera data by an accuracy of
one frame or 0.033s. The synchronization between aircraft and rack was done in a comparable manner. In
exchange a radio controlled clock was used as trigger source.
C.
Experiment Results
The test flight was done within the 13th DLR parabolic flight campaign at February 13th, 2009. The results
of the different test are examined next.
1.
Camera and Data Synchronization
The synchronization of the camera and data records has been finally done using the Image Processing
Toolbox of MATLAB. The software also allows a tracing of the central hub of the deploying boom during
the deployment. Therefore, information on deployment speed and vertical height over cabin ground could
be generated.
The results are combined records in form of high resolution movies that contains the synchronized visual
records of all eight cameras, the planes vertical acceleration and altitude sensor, the pressure and gas flow
within the gas supply system, and the mentioned deployment velocity and floating height of the foam core.
Furthermore, the variation of the power level of the supplying pump is marked within the included charts.
Figure 11 shows one exemplary frame of a record. The upper part shows the camera frames and the lower
section contains four charts for general overview on the recorded data and one line at the bottom for the
exact values of the current frame. For a detailed examination of one experiment the record can be opened by
any conventional media player. Point of special interest can be easily investigated by interrupting or slowing
down the playback or even watch the deployment frame by frame.
8 of 11
American Institute of Aeronautics and Astronautics
(a) t = 0.0s
(b) t = 2.0s
(c) t = 4.2s
(d) t = 6.8s
Figure 12. Chaotic deployment of a boom without deployment control concept
2.
Concept I: Chaotic Boom Deployment
The deployment test of booms without any deployment control mechanism generates the expected results
(see Fig. 6 and Fig. 12). An initial impulse, given to the coiled boom by the holding experimenter, provoked
a directed deployment during the first part of the unfurling (see Fig. 12(a) and (b)). 2.5 seconds after release
the boom decreases its velocity in aircraft length direction and in parallel increases the diameter of the boom
spool. More detailed, the deployment starts as a continuous process and passes into a discrete one. The more
the spool diameter increases the more short segments of the boom deploy locally and the more temporary
hinges of non deployed boom parts arise that interconnects the already deployed stiff parts. Summing up,
the spool with an initial circular windings transforms to a wrapped polygon with multiple windings. During
the further deployment process the number of temporary hinges decreases continuously until the last one
transforms to a stiff section.
This behavior generates two major drawbacks: At first, the temporarily formed hinges indicate an overstressing of the material as the bending radius of the boom fall locally below the recommended 100mm to
values between 20mm and 30mm (see Fig. 12(d)). However, a later inspection of the boom did not show
any ruptures. The second disadvantage is the mentioned discreteness of the last deployment parts. The
multiple sudden deployments of small segments act as unpredictable transient excitations that will be a hard
challenge for an AOCS. In addition, the hard stiffness gradients can seriously damage the boom in the highly
dynamic deployment phase.
Although the used boom has only a length of 8m a complete deployment could not be achieved as
the boom strikes against the cabin walls during deployment and became finally clamped. During the 25
test parabolas 5 chaotic deployments had been performed and in summary it can be stated that a total
deployment can be achieved if the initial impulse is high enough or the boom is short enough. But high
initial impulses cause high deployment velocities which conflict with the demand on controllability.
Figure 13. Electric tip deployment 3.73s after motor activation
9 of 11
American Institute of Aeronautics and Astronautics
3.
Concept II: Electric Tip Deployment
The concept performed as predicted and deploys the same test boom five times in a directed manner (see
Fig. 13). The repeatability of the deployment was verified and a later inspection of the used boom did
not show any ruptures of the material or de-bonding of the booms flanges. The separation of boom and
deployment mechanism at the end of each deployment process was also uncritical.
4.
Concept III: Inflation Tip Deployment
A total number of 15 deployments of the inflatable mast were done. Therefore, three different booms
were unfurled each five times. Except for the failed first deployment all other inflations perform well (see
exemplary Fig. 11). As the electric power provided to the gas pump was controlled by the test PC the tests
could be run with different pump power characteristics. Some deployments start using 100 % of the available
power, other start with 80 % or 70 %. Moreover, the pump power was varied during a few deployments and
also stopped and restarted in some cases. The evaluation of the recorded sensor data delivers the following
average values: To start the deployment using full pump power, the differential pressure between boom hose
and cabin rose temporarily up to 25.26mbar. After this peak a stationary value of 6.5mbar was measured
during continuous deployment phase. Furthermore, the required start pressure for 80 % pump power was
20.43mbar and 70 % requires only 13.64mbar. These values indicate that the majority of the initial pressure
is needed to accelerate the coiled booms inertia to the final static deployment speed. The required pressure
to keep a deployment velocity which is an indicator for the necessary introduced energy to break the Velcro
connections, did never rise above 7mbar. The mentioned variation of pump power during deployment also
delivered excellent results. Some deployments successfully demonstrate that a total stop and restart of the
unfurling process is possible by interruption of the gas flow.
5.
Experiment Conclusion
All experiment objectives as defined in section III.A were achieved. The deployment of the boom without
controlling concept was very chaotic as it was previously simulated. The both tested deployment control
principles performed very well. Both concepts enable repeatable, directed and controllable boom deployment.
IV.
Conclusion
The principle of the rollable CFRP boom is a promising concept that combines simplicity with outstanding
properties and easy handling. Various methods for a save deployment had been demonstrated during on
ground test and within an artificial 0g environment. In contrast to conventional pantographic structures no
hinges are necessary the deploy the structure. Thereby, the probability of deployment failures is significantly
decreased. Moreover, the boom material is completely cured on ground. Thus, in comparison to rigidizableinflatable structures, the booms can be tested on ground before launch as an excellent contour accuracy and
repeatability is given. Again, the very low coefficient of thermal expansion of CFRP induces an attractive
thermal behavior of this structural building block. The booms are scalable in cross section, length and
material thickness and can be adapted to various applications. Having in mind their properties, they are
an appropriate choice for antennas, instrument booms, reflectors, sunshades, solar sails, solar arrays, and
deorbiting systems.
V.
Outlook
The presented booms and the electric tip deployment concept will be the design baseline for the upcoming
GOSSAMER-17 demonstrator (see Fig. 14). A modified version of the booms is also foreseen to form the
support structure of the deorbiting system demonstrator DEORBIT-SAIL that will be developed in the next
three years by a broad international consortiumb under funding of the European Community. The launches
of both systems GOSSAMER-1 and DEORBIT-SAIL are scheduled for 2014.
b University of Surrey (leader), DLR - German Aerospace Center, California Institute of Technology, ASTRIUM S.A.S., Stellenbosch University, University of Patras, Athena Research and Innovation Center in Information Communication & Knowledge
Technologies, Middle East Technical University, Surrey Satellite Technology Limited, ISIS - Innovative Solutions In Space BV
10 of 11
American Institute of Aeronautics and Astronautics
Figure 14. GOSSAMER-1 deployment sequence including optional jettison of boom and sail deployment units
Acknowledgments
We gratefully acknowledge Ulrike Friedrich, Ludger Fröbel, Michael Turk and Christoph Sickinger for
their successful efforts on enabling the test flight.
References
1 Footdale,
J. N. and Murphey, T. W., “Deployable Structures with Quadrilateral Reticulations,” 50th
AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Palm Springs, CA, USA, May
4-7 2009.
2 Allred, R., Hoyt, A., and McElroy, P., “UV Rigidizable Carbon-Reinforced Isogrid Inflatable Booms,” 43rd
AIAA/ASME/ASCE/AHS/ ASC Structures, Structural Dynamics, and Materials Conference, Denver, Colorado, USA, Apr
22-25 2002.
3 Sandy, C., “Next generation space telescope inflatable sunshield development,” IEEE Aerospace Conference Proceedings,
Vol. 6, Mar 18-25 2000, pp. 505–519.
4 Fang, H., Lou, M., and Huang, J., “Design and Development of an Inflatable Relectarry Antenna,” Tech. rep., JPL, May
15 2002, IPN Progress Report 42-149.
5 Straubel, M., Sickinger, C., and Langlois, S., “Trade-Off on Large Deployable Membrane Antennas,” 30th ESA Antenna
Workshop, Noordwijk, The Netherlands, May 27-30 2008.
6 Herbeck, L., Leipold, M., Sickinger, C., Eiden, M., and Unckenbold, W., “Development and Test of Deployable UltraLightweight CFRP-Booms for a Solar Sail,” Spacecraft Structures, Materials and Mechanical Testing, Vol. 468, Noordwijk, The
Netherlands, 2001, p. 107.
7 Geppert, U., Biering, B., Lura, F., Block, J., Straubel, M., and Reinhard, R., “The 3-step DLR-ESA Gossamer road to
solar sailing,” Advances in Space Research, Vol. In Press, Corrected Proof, 2010, pp. –.
8 Sickinger, C., Verifikation entfaltbarer Composite-Booms für Gossamer-Raumfahrtsysteme, Dissertation, Technische Universität Carolo-Wilhemina zu Braunschweig, Mar 2009, Publisher: Shaker, ISBN: 978-3-8322-8049-9.
11 of 11
American Institute of Aeronautics and Astronautics