WASHINGTON — U.S. industry officials, frustrated by what they say is a dearth of opportunities to host U.S. Defense Department payloads on commercial satellites, appear to be setting their sights on a space surveillance mission slated for launch around 2021.

Although the Space Based Space Surveillance (SBSS) follow-on mission has been described by the U.S. Air Force as one that would feature dedicated government satellites, industry officials say the service recently indicated it is open to a different approach.

Janet Nickloy, vice president of responsive ISR solutions at Harris Space & Intelligence Systems of Melbourne, Florida, said that “there was commentary by Government officials accepting alternative architecture solutions, including hosted payloads,” at an SBSS industry day held by the Air Force in September.

The SBSS is intended to keep tabs on the geosynchronous-orbit belt some 36,000 kilometers above the equator, which is home to the Air Force’s most crucial satellites for missile warning and nuclear command and control. U.S. defense and other government officials, saying space capabilities are increasingly threatened by Russia and China, have placed a high priority on the program.

Geosynchronous orbit also happens to be the operating location of most commercial telecommunications satellites, which by virtue of launching fairly frequently are viewed as good candidates to host government payloads whose schedules can be difficult to predict.

The current SBSS satellite, the Block 10 pathfinder, was launched in 2010 and performs its mission from a sun-synchronous, low Earth orbit. As publicly described by Air Force officials, the follow-on system would consist of three satellites, also in low Earth orbit.

“The system performance requirements reflect the Government’s Reference Architecture, which is a free-flier solution,” Nickloy said via email. “The government will need to demonstrate some flexibility to tap into the value proposition of hosted payloads.”

Kay Sears, president of Intelsat General Corp. of McLean, Virginia, the U.S. government services arm of global satellite operator Intelsat, said there a number of Air Force missions in the planning books that lend themselves to a hosted payload solution. In an Oct. 8 interview here at the Hosted Payload Summit organized by Access Intelligence, she said the SBSS follow-on mission “is probably the first one that is ripe” for that approach.

Industry officials said they expect the Air Force to move forward with two rounds of requests for information on the SBSS program in the coming months. The current satellite is expected to last until about 2017, and Air Force officials are planning to use the service’s Operationally Responsive Space Office to develop an interim satellite that would demonstrate technologies for the follow-on system.

SBSS aside, industry frustration with the lack of opportunities to host military payloads had been voiced both before and during the conference. The Air Force in 2014 created the Hosted Payload Solutions, or HoPS, contracting vehicle to expedite such arrangements by standardizing processes and hardware interfaces, selecting 14 companies as prequalified providers.

But the contracting vehicle’s only user to date has been NASA. In July 2014, the Air Force, acting on NASA’s behalf, awarded three commercial telecommunications satellite makers contracts to design accommodations for an atmospheric sensor, known as Tropospheric Emissions: Monitoring of Pollution, or TEMPO.

“HoPS has become a four-letter word, hasn’t it?” Daniel Lim, a vice president at cubesat integrator TriSept Corp. of Chantilly, Virginia, said as he introduced a panel on the military’s use of hosted payloads.

While praising the Air Force for making progress on the contractual elements necessary to make use of hosted payloads, industry officials were in near-universal agreement that the program was off to a slow start.

Hayley McGuire, deputy director of advanced government space systems at Boeing Space and Intelligence Systems of El Segundo, California, said the company had expected the Air Force to issue about two task orders a year under the contract.

Despite the lack of HoPS utilization, the Defense Department has taken advantage of at least one major hosted payload opportunity in the last year. The U.S. Missile Defense Agency has contracted with an unspecified satellite operator — widely believed to be Iridium, which is deploying a second-generation constellation in low Earth orbit starting next year — to host kill assessment sensors on multiple spacecraft.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.