The US Air Force's Space Fence program has been a long time in the works, and will replace the now defunct Air Force Space Surveillance System (AFSSS). Construction of the new Space Fence is currently ongoing at the Kwajalein Atoll site, around 2,100 mi (3,380 km) southwest of Honolulu, Hawaii.
But by first building a smaller test facility, Lockheed Martin is looking to trial its new radar technologies ahead of the Space Fence entering operation. Where the AFSSS was capable of detecting objects around the size of a basketball, the new system will be able to pick up objects as small as a softball by relying on S-band ground-based radars with higher wave frequencies rather than the VHF radar system previously in use.
Among the upgrades is a monolithic microwave integrated circuit technology that includes semiconductors made from gallium nitride (GaN). This versatile material has played a role in numerous advances in LED lamps (including a Nobel Prize-winning blue LED in 2014), along with promising developments in solar cell technology. Lockheed Martin says its use in radar array systems makes for grater power density, efficiency and reliability.
Though Lockheed Martin already has more than 400 S-band ground-based radars in operation around the world, it says there are lessons to be learned from the installation at its new test site. It will also use the facility to validate the hardware, firmware and software designed to detect, track and catalog orbital debris more than 1.5 million times a day to help avoid collisions.
"The opening of this test facility marks an exciting milestone for Space Fence," says Bruce Schafhauser, director, Lockheed Martin Space Fence. "We are one step closer to dramatically improving space situational awareness and increasing orbital debris monitoring by tenfold. By using an open-architecture system, Space Fence can adapt to future missions requiring various tracking and coverage approaches."
Meanwhile, construction of the Space Fence at the Kwajalein Atoll site forges ahead, with 4,500 cubic yards (3,440 cubic meters) of concrete already poured to provide a foundation for the site and the start of ring walls to support the facility's inflatable roof. The Space Fence is slated to begin operations in late 2018. Once complete, it will track hundreds of thousands of satellites and debris orbiting the Earth.