Pushing the Boundaries of Space Antenna Technology

Pushing the Boundaries of Space Antenna Technology

Apr 15, 2019

BY TOM CAMPBELL

Harris’ long-running space antenna reflector business is responding to today’s challenges through an expanded portfolio of solutions that includes innovative new designs—and one not-so-secret ingredient.

From the television programs we watch, to our cell phone conversations, to the internet we access for business and personal use, the world relies on satellite-based antenna systems receiving continuous streams of big data and reflecting them back to locations on Earth reliably and quickly.

Nearly 50 years ago, Harris made a commitment to advancing satellite communications with innovative space antenna solutions—in particular, lightweight reflectors that pack up tightly inside rockets for launch and then unfurl in space once the satellite is in its proper orbit. We started with a radial rib design (something like the classic umbrella) and graphite composite materials for the frame. We developed a unique, highly reflective mesh material that we “knit” ourselves to serve as the reflector surface. And we constructed what is still the world’s largest dedicated assembly, integration, and test facility to be able to produce quality mesh reflectors in quantity. 

Over the decades, our space antenna reflector business has grown rapidly in alignment with the demand for more and better satellite communications, and Harris is now recognized as the most experienced unfurlable mesh reflector manufacturer in the world. But leadership has its challenges, not the least of which is remaining relevant and competitive in a marketplace that is rapidly changing. 

So today, Harris is once again pushing the boundaries of space antenna reflector technology. We are answering the call for higher signal throughput, frequency reuse, faster production, and decreased mission risk with an expanded portfolio of reflector solutions that includes revolutionary new approaches to achieving low-stowed volume constraints, increasing the mission value of smallsats, and reducing costs to satellite owners.

EXPANDING OUR PORTFOLIO 
Harris’ Radial Rib Reflector, with deployed apertures ranging from 3.5 meters to 9 meters in diameter, has been a tried-and-true top performer for satellite communications and broadcast systems working in frequencies from UHF to Ka band. Compared to conventional solid reflectors in the 2-meter to 3-meter class, Harris’ Radial Rib Reflector provides more spot beams for more efficient frequency reuse and greater capacity. 

Our Folded Rib Reflector design—think of the compact foldable umbrella that fits in your briefcase—followed the Radial Rib Reflector. With deployed apertures as large as 18 meters, it stows in even less space for launch. Available for satellite applications from UHF to S band, these larger reflectors serve high-gain missions and accommodate smaller handheld radios on the ground. These workhorse antennas are still vital, particularly for the mobile-satellite service market and science missions.

A few years ago, Harris introduced another lightweight alternative to bulkier, larger solid reflectors: the Fixed Mesh Reflector. “Fixed” refers to the rigid reflector structure, which stores as-is for launch. Spaceflight-qualified versions of the Fixed Mesh Reflector in sizes up to 3.5 meters fit neatly into today’s generation of rockets. Recent improvements enable this reflector to meet V-band requirements. It is the first mesh reflector to operate through 50 GHz. Recently we designed a 5-meter version of the Fixed Mesh Reflector to fit into the large fairing of the next-generation heavy-lifting launch system, New Glenn, to enable future ultra-high-throughput satellites. 

INTRODUCING THE PERIMETER TRUSS MESH REFLECTOR
Demand for even more accurate, compact, and lighter reflectors prompted Harris to design the Ka-band Perimeter Truss Reflector.  Introduced in late 2018, the Perimeter Truss Reflector offers a stowed height that is 30 percent shorter than today’s state-of-the art reflectors and has 50 percent less mass than heritage reflector designs. Scalable from 3 meters to 22 meters, the Perimeter Truss Reflector will support the most technically challenging communication, science, and synthetic aperture radar missions. 

A HIGH-QUALITY ANTENNA FOR SMALLSATS
When configured as constellations, smallsats have the potential to deliver significant benefits to mission owners, like improved mission resiliency and affordable, persistent coverage. Harris’ new Ka-band High Compaction Ratio Reflector Antenna brings big value to smallsats. 

Our 1-meter reflector and feed can fit into a smallsat with a 2U stowed volume, approximately the size of a box of tissues. And yet it is powerful, enabling high data transfer rates typically only available with large-aperture reflectors. By applying the same fabrication and surface-shaping processes as our heritage antennas, we minimize development risk for our customers. 

The High Compaction Ratio Reflector Antenna design can be scaled up to 5 meters in diameter, a size that neatly fits into a quarter of an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) class satellite. 

REDUCING RISK, SCHEDULES, AND COSTS WITH BUILD TO PRINT MODELS
Most big-dollar projects must weigh desired features and capability against cost, and this generally requires trade-offs. Harris is enabling mission owners to get more for their dollars through a “build to print” selection of some of our most successful reflector designs. With their foundational designs completed and with manufacturing facilities and processes already in place, these solutions not only reduce design costs, but also reduce risk for our customers through their proven performance, and they accommodate fast turnaround production schedules. 

Our build to print models meet a wide range of needs, including low-stowed volume and low-mass requirements, and they support UHF to V-band applications. These designs use Harris’ patented, highly reflective mesh surfaces and proven structures for reliable, precision deployment. We streamline manufacturing time and costs by using additive manufacturing and off-the-shelf components when possible—but we never cut corners when it comes to quality. Our reflectors are still manufactured in-house following proven processes and rigorous testing regimes.  

BEYOND DESIGN
Staying relevant and competitive in the fast-paced space industry is never easy. And when it comes to specialized technologies like space antenna reflectors, it takes more than just interesting new designs to be successful over the long haul. I believe that the not-so-secret ingredient to maintaining our leadership position is our highly experienced team of engineers and technicians. These 300 committed men and women work daily behind the high-bay doors of our factory, using proven facilities, following strict processes to the letter, and performing together as a well-oiled machine to deliver reflectors that reliably deploy in space, perform to specification, and advance the state of the art for our customers and their users.

Tom Campbell is general manager of Harris’ Space Antennas and Structures business. Harris is the number-one provider of large, high-accuracy reflectors, with more than 90 lightweight, mesh antennas on orbit.

Click here to view our entire publication on Mission Confidence: Increased resliliency, rapid response, managed risk.