Satellites. Spent rocket boosters. Stray hardware. Debris from in-space collisions. The need to accurately track the estimated 500,000 objects floating in space is only increasing. Lockheed Martin’s Space Fence team recently reached a major milestone by confirming the long-term reliability of its Gallium Nitride high power amplifiers (GaN HPAs) – the technology that will allow for an increase in the amount of space junk tracked by 10-fold over the current system.
Our technology-rich lives depend on the performance of the satellites that are floating in the same space as other objects and debris. Space Fence, which is scheduled to go online from Kwajalein Atoll in the Marshall Islands in 2018, incorporates a scalable, solid-state S-band radar with a higher wavelength frequency capable of detecting much smaller objects than the current system. This improves accuracy, quickens response time and expands surveillance coverage.
Lockheed Martin is working on Space Fence in partnership with Space Military Command and the U.S. Air Force Life Cycle Management Center/Space Command Control and Surveillance Division.
With construction underway and critical design review completed, the Space Fence team is focused on production of technology that will bring the system online. GaN HPAs are integral in meeting the efficiency and availability requirements for Space Fence. After more than 5,000 hours – nearly seven months – of accelerated stress testing, Lockheed Martin demonstrated greater than 99 percent confidence that the Space Fence HPAs will meet the long-term reliability goals for the Space Fence program.
Lockheed Martin is partnering with Wolfspeed, a leading provider of semiconductor products, to provide the GaN HPAs for Space Fence.
“These test results represent the culmination of more than a decade of shared investment in GaN technology,” said Steve Bruce, vice president, Advanced Systems at Lockheed Martin Mission Systems and Training. “GaN HPAs provide a significant advantages for active phased array radar systems like Space Fence, including higher power density, greater efficiency and significantly improved reliability over previous technologies.”
Wolfspeed, a division of Cree Inc., is based in Durham, N.C.
“Wolfspeed is very pleased to be teamed with Lockheed Martin providing GaN Monolithic Microwave Integrated Circuit (MMIC) HPA technology in support of the Space Fence program,” said Jim Milligan, director, Wolfspeed. “Our high performance commercial GaN products have been fielded for many years in a variety of military and commercial applications. The successful completion of this significant reliability milestone further validates that GaN has matured enough to support the 24-hour-per-day coverage needed by the Space Fence system.”
What is GaN?
Gallium Nitride (GaN) is a semiconductor material used in electronic applications as a more efficient medium for conducting electronic current.
Advantages to using GaN technology include:
- Higher Power Density: Smaller die, increased range and sensitivity
- Higher Efficiency: Decreased system demands for power and cooling
- Higher Temperature Operation: More robust, enables new applications
Today, GaN is mature, reliable, and commercially available. Working with its technology partners, Lockheed Martin has significant experience in successfully developing and deploying GaN-based products.