The Lake Kickapoo Field Station, 12 miles west-southwest of Archer City, Texas, has a 1.5 mile antenna operated by the 20th Space Control Squadron, and part of the Air Force Space Surveillance System, used for observing objects passing over the U.S. It is the primary anchor transmitter for the 'Space Fence' network for monitoring the space defense system. It extends east-to-west at about the 33rd parallel. The antenna has no public access. (Torin Halsey)
The Air Force is pressing ahead with funding and intense supportfrom Congress for the “Space Fence” system to track debris in low-Earth orbit, following delays and cutbacks driven by sequestration.
The S-Band radar, commonly called the Space Fence, is built to track objects in orbit that aresmaller than satellites. Gen. William Shelton, commander of Air Force Space Command, has said the program is critical to the health of military and commercial satellites.
It will replace the Air Force Space Surveillance System of VHF radars in place across the southern U.S. Those radars are not capable of tracking objects smaller than 10 centimeters.
“We need better capability to track, which is what the Space Fence is all about,” Shelton said March 12 at a Senate Armed Services Strategic Forces subcommittee hearing. “We need all spacefaring nations to not generate more debris, because our biggest fear is that if you get more and more debris on orbit, eventually you get to the place where debris begets debris. You have a cascading effect, and you’ve polluted the entire [low-Earth orbit].”
The International Space Station and most satellites are in low-Earth orbit, including those used for military and commercial communications and mapping.
The Obama administration’s fiscal 2015 budget request includes about $214 million for research and development for the Space Fence.
Shelton, who ordered the current system to shut down in August because of sequestration-forced budget cuts, said the delay in the replacement system was the right choice. However, work on the new system is needed quickly, he said.
The delay cost the service about $70 million, William LaPlante, the principal deputy assistant Air Force secretary for acquisition, testified last fall.
The Defense Department can track less than 5 percent of about 500,000 objects floating in space, much of which is uncontrollableand poses a threat tosatellites. The replacement system will be able to track objects “the size of a softball orbiting more than 1,200 miles in space,” according to an Air Force explanation of the system.
Space junk has already taken out a satellite. In 2009, a commercial satellite owned by U.S. communications company Iridium was hit by a defunct Russian satellite and “caused catastrophic loss.” Similar incidents could take out U.S. military and other commercial satellites, if debris is not tracked, Shelton said.
“We are so dependent on space these days that we plug into it like a utility,” Shelton said.
The new system includes a ground-based S-band radar system built on the Kwajalein Atoll in the Marshall Islands. Shelton said he expects to award a contract this spring, with initial operating capability in fiscal 2019.
The budget proposal outlines future spending for development of the Space Fence, including $291 million in fiscal 2016, $170 million in 2017, $50.6 million in 2018 and $5.4 million in 2019.
The Air Force is the only entity that looks at the entire picture in space, while individual satellite operators follow what is in the “neighborhood” around their satellites, said William Welser IV, director of research in the engineering and applied science department of Pardee Rand Graduate School.
“To date, the Air Force has been performing this global good in looking and observing what’s up there,” Welser said. “The question would be if the Air Force stops doing that, who would do it?”
Additionally, there are concerns about human safety in space, said Dave Baiocchi, a senior engineer and professor with Rand. The International Space Station has had near misses with space debris that forced the crew to take refuge in Russian-made Soyuz capsules they would use to return to Earth, and any threat could “cause a lot of concern for the future of that program,” he said.
The Navy began operating the most recent iteration of the Space Fence in 1961, with the Air Force taking control in 2004. Since then, the amount of space debris has jumped, both from the Iridium incident and the 2007 test of a Chinese antisatellite missile that destroyed one of that country’s own satellites.■