If successfully developed, the aircraft could play a vital role in surveillance over trouble spots such as Iraq.
Air force chief of staff General John Jumper said on Tuesday that he would meet next week with the head of Air Force Space Command, General Lance Lord, to map out plans to get lighter-than-air vehicles into near space.
Jumper said the air force was working with the Defence Advanced Research Projects Agency (DARPA) to develop a stealthy aircraft without metal that could be equipped with special sensors and remain in the air for months at a time.
That would help meet the demand for persistent surveillance, which is difficult with current satellites which circle the Earth in orbit at altitudes above 300km.
Unlike satellites, the new breed of near-space aircraft could hover for longer periods in one area.
Since they would be closer to Earth, far fewer would be needed to maintain surveillance of the entire globe, Jumper said.
The US military already has some aerostats or blimp-like aircraft in use to raise antennas and provide surveillance over US bases in Iraq.
But in near space, such aircraft could carry out radar and imaging missions, carry communications nodes and even potentially relay laser beams from a ground-based source against a wide variety of targets, industry sources said.
Jumper gave few details, but said one of the remaining issues was dealing with such aircraft on the ground where they could be unwieldy.