In 2011, the US Government ended SBInet, a major and unsuccessful attempt to build a virtual fence along the border that cost nearly $1 billion before it was killed; DHS is now testing aerostats, and an 80-foot tower with similar surveillance capabilities, for border security as part of an effort to exploit technologies that have been used in the wars in Iraq and Afghanistan.

The US Border Patrol is testing two blimp-shaped helium-filled balloons, which are on loan from the defense department, on the Mexican border. Congressional staff members joined DHS and Defense Department officials recently near the border town of Roma, about 415 km south of San Antonio, to see what the aerostats can do. Members of the media were given a more limited glimpse of the devices’ capabilities.

The technology has already proven successful in Iraq and Afghanistan. Now US officials think the blimps could be helpful in tracking drug smugglers and illegal immigrants on a rugged stretch of the Rio Grande that does not have a border fence.