A Raytheon Co system built into big blimp-like balloons has demonstrated capabilities that could make it easier to detect and track certain enemy ballistic missiles, the company and the US Army's manager of the programme said.
System tests in December at White Sands Missile Range, New Mexico, successfully tracked four targets mimicking tactical ballistic missiles in "high-threat" regions, Raytheon said.
The hardware was known as Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, or JLENS.
It included a targeting radar and a wide-area surveillance radar with a 360-degree look-around capability that could reach out to 540km.
Each radar system flies as high as 3km with a separate, 74m-long aerostat capable of operating aloft for up to 30 days while tethered to mobile moorings.
The bulbous, blimp-like aerostats work in pairs officially estimated to cost about US$450 million (NZ$540m) - though Raytheon has said it could lop a third off of that price.
The December 6-7 tests met all primary and secondary goals, including "launch point estimation, ballistic tracking and discrimination performance," Raytheon, the world's biggest missile-maker, said in a draft press release.
The missiles were tracked during their so-called boost phase, it said, including two that were "ripple-fired" one after the other.
JLENS' "proven capabilities" provided another tool that could help protect US and partner forces from "the growing ballistic missile threat" and other threats, Dean Barten, who managed the programme for the US Army, said in the release.
Barten's statement was confirmed to Reuters by an Army spokesman.
The army was preparing one of its two existing JLENS systems, formally known as an orbit, for a three-year exercise that would tie it in to a high-tech shield designed to protect the Washington DC area from air attack.
The second existing JLENS system could be sent overseas sooner. The system was designed to provide more time to detect and react to cruise missiles, manned and unmanned aircraft and other threats, compared with ground-based radar.
It also had been demonstrated to be capable of picking out moving vehicles that could be used for attacks, including boats, cars and trucks, according to the US Army and to Raytheon.
"We think JLENS is ready for action wherever it may be needed," Mark Rose, Raytheon's JLENS programme director said.
The programme has been scaled back sharply by the government amid Pentagon belt-tightening to help pare trillion-dollar-a-year US deficits.
What will be the main motivation for humanity's future space endeavours?Related story: (See story)
The cost of losing nature