Space Inflatables Division
Formed in the Spring of 2012, SGA-SID partnered with L’Garde, Inc. of Tustin, CA to design and develop space-qualified Next Generation High-Precision Expandable Large Aperture X & KA band antennas for satellites and other spacecraft.
The Requirement: Applications such as HDTV, Mobile TV, Fast Internet and Intranet, and bi-directional satellite to cellular device communication, amongst others, are driving insatiable demand for satellite communications bandwidth. This demand pushes satellite manufacturers to build satellites with bigger reflector sizes, higher transmitting power and higher receiver sensitivity. Volume in launcher canopies limits the maximum diameter of communication reflectors. Sophisticated, costly mechanisms are needed to deploy folded structures; these mechanisms have many fail points, and have a large mass. An innovative technology is needed to both address the technical challenge and enable further expansion of satellite services.
The Proposed Solution: Inflatable technology, the ability to deploy and inflate compact components after the satellite is in orbit, should significantly reduce launch costs and canopy accommodation challenges. Stowing inflatable components aboard satellites for post launch deployment will reduce launcher canopy size limitations.
This system will have profound positive effects in space access and space communications. The large advantages of rigidizable space structures in increased bandwidth capacity, stowage volume and cost reduction will result in significant savings in the cost of space science and communications missions and will enable missions that are presently unaffordable or impossible.
~ Click on the elements in the table below for more information ~
Satellite communications are perhaps the most ubiquitous example of human utilization of space and they have been a crucial part of the global telecommunications infrastructure for decades. They bridge the oceans for international telephone calls, bring live video footage of major events back to television studios, enable banks and retailers to conduct instantaneous financial transactions, and connect the major network hubs that extend the reach of the internet.
Inflatable/Expandable larger aperture space communication antennas are subjects of current research because of their potential for enabling high-bit-rates and reducing launcher canopy volume requirements. The ever growing need for bandwidth and huge launch costs will continue to drive satellite manufacturers and space science mission planners to look for novel solutions.
Deployable lightweight membranes and space rigidizable structures are justifiable mainly because they share the lower construction and launch costs with inflatable structures, when compared to mechanically deployable ones. A strong case can also be made that, when properly engineered, their deployment can be more reliable due to their simpler construction and in the case of inflatables and inflation-deployable rigidizables, continuous presence of the inflation force during deployment does not decrease as the deployment proceeds to its completion. Obviously, for long mission lifetimes, we need structures that do not have to be kept inflated continuously; else purely inflatable structures and apertures could be used.
This effort will culminate in the design and production of a 10 meter to 20 meter class deployable membrane antenna with an RF distortion-correction system. The system is comprised of a metalized low-CTE membrane parabolic dish supported by shape-memory composite or inflatable/rigidizable ribs.
We are researching and trading-off two lightweight antenna configurations: one based on a shape memory composite material, shown in Figure 1 and the inflatable/expandable shown in Figure 2. Among the trade dimensions to be used in the study are (a) system weight, (b) packageability/stowed volume, (c) ease and reliability of deployment, (d) surface accuracy achievable, (e) power needs for deployment and (f) overall cost.
The former configuration uses a structural fabric impregnated with a sub-Tg resin. It rigidizes after it is allowed to cool passively below its glass-transition temperature (Tg). Cooling below the Tg is easily accomplished by a proper choice of resin glass-transition temperature coupled with material surface thermo-optical properties. The latter on the other hand relies on the shape memory property of the composite used. It is as packageable as the former and deploys by virtue of the stored strain energy in the stowed configuration. The innovation in the latter approach is the use of a thermally stable, high-strain, super elastic shape memory carbon composite material for the antenna ribs, perimeter support and struts. This material shall be used as shape memory structural ribs of the parabolic dish aperture antenna.
One advantage of the shape memory deployed antenna over the inflatable/expandable is the absence of a canopy since it is not deployed by pressurization. However, the inflatable/expandable antenna may offer slightly better surface slope continuity because of the smoothing effect of pressure during the rigidization process.
Since the beginning of the space program, membrane inflatable structures held a particular fascination for space scientists and engineers. The high cost of getting even a simple payload into space made them attractive early on due to their potential for being light weight and stowable in very small volumes at launch.
NASA was the first successful developer of simple rigidizable structures with the Echo satellite series of the early sixties. One of them, a mere spherical shape of 135 feet in diameter survived for at least 5 years, preserving its accurate spherical shape on orbit before residual atmospheric drag de-orbited it. About a decade later, the Contraves Company in Europe started designing a 15-meter inflatable-rigidizable off-axis antenna aperture, using a structural fabric impregnated with a UV-rigidizable resin. The result was discouraging as the UV rigidization was not uniform (the UV rays could penetrate only a minute thickness of the composite reflector and support torus material) and the resulting reflector had lost totally its designed-for surface accuracy. And this was after an investment of close to 30-40 million of today’s dollars.
The last commercial large aperture inflatable antenna deployed in space was the Inflatable Antenna Experiment (IAE). Since that space experiment in 1996, no inflatable antennas have been flown. There have been other space experiments using inflatable structures such as the 3.5 m diameter optical calibration sphere for the Air Force and inflatable targets and decoys for the Missile Defense Agency but nothing like the IAE. The IAE was fully inflatable, including support structures. The amount of makeup gas needed to replenish the inflatant lost within the support structures due to meteoroid hits wass prohibitively high. The fully inflatable antenna-canopy system also required inflatant replenishment although not to the same extent needed for the support structures. However, for long duration missions it is not feasible due to the fact that the amount of makeup gas needed rises as the square of the mission lifetime.
Our proposed approach does not require pressurization to maintain an accurate antenna surface shape. No makeup gas is needed for either candidate configuration and the support structures are themselves either rigidizable or made of a shape memory composite. The beginning TRL level of our innovation is between TRL 3 and 4 for the inflatable/expandable and at level 3 for the shape-memory composite. In contrast to the IAE and other space structures that have flown, the material we will use in both our proposed approaches is a low, virtually zero, CTE polyimide. The use of low CTE polymide will affect a more thermally stable antenna reflector and eliminates one source of antenna surface error on orbit.
Ten-meter to 20-meter class foldable membrane apertures are difficult to manufacture with antenna surface quality on the order of a fraction of a millimeter such as those required for use in the Ka-band. Even if we are able to manufacture them accurately and precisely on the ground, orbit-generated surface errors, particularly those due to varying thermal loads cannot be corrected by expert design alone. This is particularly important in the high frequencies at Ka-band. A real-time corrective method is a sine-qua-non for this class of apertures. There has been much previous theoretical work on the subject - electrostatic shaping methods, smart membranes and smart structures imbedded in membranes, and a host of others - but we have not seen any proof that these will work on a real-world inflatable rigidizable reflector system. Thus, we have teamed with L’Garde, Inc. to prove the feasibility and demonstrate what appears to be the most promising approach.
Inflatable/expandable antennas are fabricated using flat gores of metalized polymer materials. The rigidizable gores are seamed together at the edges to form the RF reflective surface.
There are a number of factors affecting the ultimate surface accuracy of the antenna. These can be divided into those due to (a) manufacturing and those due to (b) on-orbit environment.
• Number of (flat) gores
• Gore shape deviation from ideal shape
• Gore seaming errors
• Gore and seam material property variation: thickness, modulus, CTE, etc.
• Antenna mounting errors – (a) radial mounting errors and (b) out-of-plane mounting errors.
On-Orbit Environment Effects:
• Temperature change and temperature gradient over antenna reflector surface
The useful lifetime of the membrane antenna and its support structure in space is a function of time in the space environment. The space environment hazards include micrometeoroids, charged particles and ionizing radiation (UV, VUV, protons, electrons). It is imperative that the materials be resistant to these space hazards. We estimated that a 15-year mission life in Geosynchronous Earth Orbit (GEO) would result in about 109 rads (1 GRad) of absorbed radiation dose. The effect of ionizing radiation resulting in 1 GRad of absorbed dose using 4MeV protons from the tandem Van de Graaf accelerator of the Brookhaven National Laboratory was tested on a sample of urethane elastomeric impregnated Kevlar fabric. The exposure to 1 GRad caused some discoloration and stiffening of the composite as expected. However, the exposed composite held very well and retained its integrity after exposure enabling the performance of ASTM D1043-10 on the irradiated sample.
NASA recently announced granting of “real-estate” on the outside of the ISS to NanoRacks, LLC. Specifically, this is allocation of the JAXA External Facility (EF) that is available as a NASA resource. Working in cooperation with Astrium, NA, NanoRacks is commercially funding the development of the External Platform Program (EPP), which will be operational in early 2014.
Utilization of the EPP allows the SpaceGroundAmalgam team to test in the rigors of space without the cost, time and risk of a stand-alone demonstration. Our systems and hardware will be deployed on the outside of the station for several months, allowing data to be returned and key components of the hardware to be evaluated. Up mass is via NanoRacks’ Space Act Agreement allowing use of any cargo ship deploying to the Station, and down mass, via NanoRacks, will be either the Soyuz or SpaceX Dragon. This is video of the EPP.
We believe using the NanoRacks EPP on the ISS is the best solution for a rapid, low-cost demonstration and qualification of new technologies in space. SpaceGroundAmalgam LLC intends to offer its two initial products within 36 months of funding and launch of the first antenna demonstration to the ISS.
The demonstration will test the inflation in space, the rigidization process and the actual RF performance of the antenna. Our location outside the station is perfect for video monitoring of each stage.
The in-depth familiarity with satellite and component manufacturing and selection of a top polymer and materials company in polymer-inflatable components gives SpaceGroundAmalgam, LLC the highest chances for success in leading the inflatable component market development for satellites. SpaceGroundAmalgam LLC intends to establish standards in inflatable antenna technology for satellite applications.
Years of Experience: 27
Position: President, SpaceGroundAmalgam, LLC
Responsibilities include; overseeing general administrative requirements, budgeting, conduct and manage research efforts, manage technical and business proposal development and develop implementation strategy.
Education: Computer Information Systems, Strayer College Fredericksburg, VA
Project experience includes:
• Managed advanced commercial ASIC technology exploitation, high-speed Type-1 (>10GBps) encryption technology development, advanced optical and wireless internetworking technology developments.
• Created team and led development of Cisco Systems, Inc.’s first small satellite LEO router and custom developed hardware/commercial software based GEO COMSAT router – demonstrating the value of leveraging internet-protocol technologies in space.
• Led development and execution of Cisco’s Internet Routing In Space (IRIS) Joint Concept Technology Development with USSTRATCOM.
• Managed lunar lander technical evaluation team for Odyssey Moon Ltd.’s Google Lunar X-Prize project.
• Designed ground TT&C/data exfiltration system for Sentinel Satellite (commercial L1 solar wind monitoring spacecraft).
Demonstrated Ability: Building engineering and business teams to adapt/customize commercial off the shelf technologies for use on-board satellite/space systems. Develop new technologies and best practices for tightly coupling space and ground systems (sensors, comms, processing & dissemination). Leading new US Tier-1 Ally space systems solutions development and technology adoption. Creating diverse-background global teams to drive technology innovation.
Daniel Kevin Rockberger
Years of Experience: 10
Position: Chief Engineer, SpaceGroundAmalgam, LLC
Mr. Rockberger’s responsibilities are to provide technical guidance to the project and to L’Garde for the design and development the inflatable/expandable antenna. He will also play a major role in constructing the prototype (phase II), testing of the hardware and construction of the verification package.
Education: MSc Space Studies, International Space University, France. B.Sc Mechanical Engineering,Technion Institute of Technology,Israel.
Project experience includes:
• Mechanical design, fabrication, assembly, and testing of spaceflight hardware and specification definition and design of Mechanical ground support equipment (MGSE).
• Mechanical structure Engineer on 3 communication satellites (AMOS series)
• Design and testing of composite structures for the NASA Goddard Lunar Reconnaissance Orbiter.
• Mechanical lead on 8 Nano satellite projects, first to be launched in 2013.
• Founder of NSL Satellites Ltd.
• Unmanned Arial vehicle designer, Engineer and manufacturer.
Demonstrated Ability: Designed and flown numerous mechanical parts and structures on various satellite missions from 2006 -present.
Designed, managed, tested and integrated 3 Innovative cubesat missions.
Has written a full specification for a large communication satellite environment controlled and monitored transportation container and specifications for structure parts (including heat pipes) shipping containers.
Written 5 papers in the satellite development, integration and testing realm.
Dr. Raz Tamir
Years of Experience: 19
Position: Managing Director, SpaceGroundAmalgam, LLC
Dr. Tamir’s responsibilities are to provide technical guidance to the project and to L’Garde for the design and development the inflatable/expandable antenna. He will also be responsible for helping manage supplier and partner relations during the project.
Education: PhD Computer Science, Hebrew University of Jerusalem, Israel. MsC Aerospace Engineering, the Technion University, Israel
Project experience includes:
• Nano-Satellites Department Management (since 2007).
• Leading teams of engineers for novel algorithms for satellite real-time software, including space and ground segments.
• Satellites navigation and control algorithms development
• Development of sensors, actuators and algorithms for satellites command and telemetry.
• CEO and Founder - INSA the Israeli Nano-Satellite Association.
Demonstrated Ability: Integrated various sub-systems on Israeli satellites since 2002. Designed, managed and integrated two Nano-Satellites in the last five years (first to be launched in 2013). Written 14 papers, 6 in the satellite development, integration and testing realm.
Dr. Arthur L Palisoc
Years of Experience: 22
Position: L'Garde VP of Engineering
Dr. Palisoc’s responsibilities as PM at L’Garde include budget and schedule control as well as engineering resource management. He will also direct the technical aspects of the reflector analyses and design in coordination with SGA.
Education: Ph.D. and M.S., Engineering: University of California, Irvine
Project Management Experience:
• Managed the 4-year AFRL Sensor Calibration Device (SCD) program. The objective was to analyze, design and build two spherical calibration objects for the calibration and test of ground and space assets.
• Managed the 2-year Large Inflatable Structures (LIS) program. Objective was to design and build large aperture inflatable antennas. A 3m diameter and a 7m diameter were built.
• Was the program manager on the L’Garde side for DARPA’s ISAT program (Innovative Space-Based Radar Antenna Technology). The antenna was a 304m long truss antenna for use in GMTI applications. It was designed to fit within the 5m-diameter fairing of our larger boosters.
• Designed, coded, tested, and implemented a finite element based software for the nonlinear analysis of structures. Was the program manager of a Phase I and Phase II SBIR from NASA JPL to enhance the L’Garde finite element code FAIM (Finite Element Analyzer for Inflatable Membranes).
• Designed the surface accuracy measurement system used on the IAE. Supervised the analysis, design and build of the entire effort.
Inflatables not only address existing component markets but also create new opportunities to enhance capability. The initial products to be commercialized include inflatable reflectors, booms and solar arrays. These components have no, or a very limited, need for supporting structure and allow storage in a folded position for launch. In the longer term, ongoing R&D processes could generate a large variety of inflatable products to address communications, power, weight, size and launcher faring accommodation needs of satellites and other spacecraft.
Specific nearer term examples could include:
• Small-Satellite class high precision shape memory composite large aperture antennas.
• Cubesat class expandable shape memory composite large aperture antennas (1:5 to 1:8 packing efficiency enabling a ~1m aperture antenna to be launched/deployed from a 1U Cubesat module).
• Contingency Communications antenna for Planetary Mission Systems.
• VSAT class terrestrial-based inflatable antennas (ease of deployment by non-expert users).
SpaceGroundAmalgam LLC enjoys the unique combination of experienced staff with many years of accumulated experience in developing satellites, a deep understanding of both current and future needs of the space market and the ability to quickly launch and test these core technologies on the ISS and Nano-satellites.
Calling across the ecosystem of satellite bus component and subsystem suppliers as well as the satellite manufacturers and operators are a key part of our success metric. While SGA’s inflatable component line isn’t limited to communications satellites, we’ve decided to focus on this sector of the market to establish our initial beachhead accounts.
Additional information about our inflatable/expandable solutions is available after signing an SGA non-disclosure agreement.
Contact us to learn more about the SGA Space Inflatables Division, our products and solutions.
Rick Sanford featured speaker at the Enterprise Innovation Symposium May 8-9, 2013
SGA, LLC wins NewSpace2012 Business Plan Competition.
NBC News coverage of SGA Win.
CBS News coverage of SGA Win.
L'Garde and SGA sign Memorandum of Understanding.