NEW YORK — The U.S. Defense Department is investigating whether to field a group of small satellites — perhaps operated by commercial industry — that would assure communications with unmanned aerial vehicles flying on the edge or outside of conflict zones, military and industry officials said.

The project, called Airborne Intelligence, Surveillance and Reconnaissance (AISR), would feature satellites with four beams in Ku- and Ka-band to assure that sufficient satellite bandwidth is available for outrider Global Hawk or other unmanned aircraft without depriving satellite links to those in the thick of a conflict zone, officials said.

Despite the arrival of the Wideband Global Satcom (WGS) X- and Ka-band satellites, whose capacity dwarfs their predecessors in terms of throughput, the U.S. Air Force is concerned that demand on WGS capacity over the years will be greater than what is available on these spacecraft.

AISR would station satellites in geostationary orbit to assure that the unmanned craft would be able to beam their video and other data for relay to ground commanders even if WGS spacecraft were operating at near-saturation levels. The alternative would be to devote a WGS satellite beam to the Global Hawk operating on the periphery of a conflict zone, resulting in a shortage of in-theater capacity.

AISR is one of numerous proposals that the Air Force is weighing in the wake of the Transformational Satellite Communications System’s cancellation.The Pentagon cancelled the T-Sat program in 2009 after the spacecraft designs grew too big, complicated and expensive.

But the requirements that T-Sat was supposed to address have not disappeared, which is why the Air Force is now taking them up, one by one, to distribute among smaller programs whose budgets are less likely to get out of hand.

AISR is one of these mission ideas found in the Air Force’s broad agency announcement dubbed “Milsatcom Commercial Architecture Option,” now out for industry review.

Air Force Col. Charles Cynamon, commander of the Milsatcom Network Integration Group, said AISR, which could be built by, or with, a commercial satellite fleet operator, represents an evolution in the way the Air Force looks at the commercial satellite sector.

Addressing the Satcon conference here Oct. 13, Cynamon said that a decade ago, the U.S. Defense Department and the commercial satellite sector had an equivalent number of communications satellites in orbit. Now, he said, “when you look at the number of payloads going up,” commercial telecommunications satellites far outnumber their military equivalents.

AISR satellites — one for training over the United States and at least two others in orbits over other regions — could be owned by a commercial satellite operator and leased to the military. Alternatively, the military could own an AISR payload that could be placed on a commercial satellite.

Cynamon described the AISR satellite as a free-flying spacecraft carrying four antennas, two in Ku-band and two in Ka-band. Global Hawk aerial vehicles currently operate in Ku-band but are gradually being transitioned to a piece of the Ka-band spectrum that has been reserved for military use.

“We are operationally limited, even if we use military Ka-band, on Global Hawk,” Cynamon said. “It comes down to the sharing of apertures (antennas) for tactical warfighting and AISR users.” He said the U.S. Navy’s Broad Area Maritime Surveillance aerial system also could be a user of the AISR satellite.

Cynamon said initial contracts for studies on AISR could be awarded before the end of this year.

U.S. Air Force Col. Michael Lakos, chief of the Milsatcom division, said the Space Command’s four main missions — missile defense; protected satellite communications; positioning, navigation and timing through GPS; and assured access to space through the Atlas and Delta launch vehicle programs — take up most of the budget.

“After you fulfill those requirements, there is not a lot of money left” for new initiatives, Lakos said here Oct. 14.

Peter B. de Selding was the Paris bureau chief for SpaceNews.