PARIS — Commercial satellite fleet operators are applauding a U.S. Defense Department proposal to lease a full commercial Ku- and Ka-band telecommunications satellite covering the Middle East for 15 years as an example of out-of-the-box thinking but expressed doubts about its feasibility.

These companies said the proposal, made in the form of a request for information by the Defense Information Systems Agency (DISA), illustrates how far the Pentagon’s thinking has come with respect to the use of commercial satellite bandwidth.

“This is an interesting proposal that would have been unthinkable even a year ago or so,” said an official with one satellite operator, speaking of DISA’s Assured Satcom Services in Single Theater, or ASSIST, concept. “But I would not hold out much hope that it can result in a contract, at least not in its current form.”

An official with another satellite operator that also does regular business with DISA expressed a similar view and added that industrial interests in the United States might also play a role in scuttling the ASSIST idea insofar as it might result in fewer military-owned telecommunications satellites being built.

DISA set an April 15 deadline for industry responses to the ASSIST solicitation, which asks the commercial sector to propose building a mixed Ku- and Ka-band telecommunications satellite that would be used by the U.S. Central Command in the Middle East, South and Central Asia, and North Africa. It is this region in which the Department of Defense, which is the world’s single largest buyer of commercial satellite bandwidth, invests most of its annual commercial satellite budget.

The Ku-band frequencies would be used for airborne intelligence, surveillance and reconnaissance systems. The Ka-band would be reserved for tactical ground links.

DISA proposes to spend $440 million over the 15-year life of the satellite, with that sum also including investments in ground terminals as needed to use the selected satellite.

According to DISA, the U.S. Central Command currently uses Ku-band capacity on 20 different commercial satellites in the region. The agency estimates that what it calls its “aggregate sustained demand” is more than 5 gigahertz of bandwidth permitting links with more than 1,200 terminals. Most of this capacity is purchased in small pieces for periods of one year.

Buying commercial capacity this way — multiple contracts, each for a relatively small amount of capacity, for one-year periods — is much more expensive than taking out a long-term lease. Commercial satellite owners and the Defense Department have been discussing for several years how to introduce greater predictability to the military’s bandwidth purchases. This would allow operators to better plan for future satellites with the promise of an anchor customer. For the military, it would lower the cost of bandwidth.

“Buying commercial bandwidth on the spot market is the most inefficient way,” said U.S. Air Force Maj. Gen. John E. Hyten, director of space programs in the Office of the Assistant Secretary of the Air Force for Acquisition. “We need long-term agreements to assure supply.” Hyten made his remarks April 14 during the U.S. National Space Symposium in Colorado Springs, Colo.

But wide agreement on the problem has not, up to now, resulted in bulk purchases of commercial bandwidth over the long term. This capacity supplements bandwidth from the military’s own satellites, such as the fleet of Wideband Global Satcom Ka-band satellites now being deployed.

ASSIST is viewed as a breakthrough in terms of commercial buying practices, even if — as may be expected of a first-time effort — it is seen as infeasible for multiple reasons.

Speaking informally, and under the condition of anonymity so as not to appear critical of one of their biggest customers, industry officials said the DISA deadline for the capacity being available — December 2014 — is too close to allow bidders to respond fully to the requirements in the ASSIST request for information.

First off, they said, Ku-band capacity over the Middle East is already in short supply and is selling for around $1.5 million or more per 36-megahertz-transponder equivalent. Asking an operator without booked capacity to step in with a new satellite whose frequencies are already coordinated and validated by international regulators by December 2014 may be asking too much.

Second, they said the Ka-band component poses problems insofar as few, if any, operators that the Defense Department would be willing to deal with have well-developed plans for Ku-/Ka-band spacecraft in the region.

Yahsat of Abu Dhabi, United Arab Emirates, owned by that government’s investment arm, Mubadala, is a startup operator that just launched a Ku-/Ka-band satellite, Yahsat 1A, and plans an all-Ka-band Yahsat 1B for launch within the year. It remains unclear how much unsold capacity Yahsat has available.

Another difficulty with ASSIST is that DISA reserves the right to redirect the satellite bandwidth to different theaters during the contract’s 15-year life. “How would frequency coordination be handled for such a move?” one industry official asked DISA, according to a DISA fact sheet published after the information request.

DISA’s answer was that while the agency would seek such a change of coverage only as part of a long-duration shift, it nonetheless would be the job of the service provider to assure the frequency coordination needed to allow the change in bandwidth footprint.

This requirement adds a serious complication to any attempt to register Ku- and Ka-band frequencies with the International Telecommunication Union, a U.N. affiliate that coordinates wireless broadcast frequencies and satellite orbital positions.

Responding to another industry question, DISA said it may be willing to have the Ku-band capacity on one satellite, with the Ka-band on another spacecraft. But “industry would be solely responsible for obtaining licensing and orbital allocation using their normal process,” DISA said.

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