By 2015, space engineers and managers at Kirtland Air Force Base, N.M., are to be ready with a range of backup options and satellite sensors that could be launched quickly if an enemy were to knock out critical U.S. surveillance satellites, or if regional commanders requested more sensor coverage.

U.S. defense officials call the concept operationally responsive space (ORS). They'd been talking about the idea for years when Congress ordered them to draft a plan in 2007. The Pentagon responded by establishing an Air Force office at Kirtland.

Now it's up to ORS Director Peter Wegner and his colleagues to prove the idea on an annual budget of $110 million - or less, under an Air Force proposal to cut that to just $10 million in 2012.

Advocates hope that projects currently under way will prove they can assemble useful satellites quickly by plugging standard attitude-control systems, power systems, processors and sensors into spacecraft frames. There's a 24-month goal for ORS Sat 1, whose frame is being built by Alliant Techsystems to carry a secret instrument made by Goodrich ISR Systems, Danbury, Conn., best known for building high-fidelity mirrors for imaging satellites.

If the satellite reaches space as planned in 2010, according to the Air Force, it will fill a "critical U.S. Central Command intelligence, surveillance and reconnaissance need."

Technical hurdles include ensuring that parts are compatible and that the satellites are reliable despite streamlined prelaunch testing. But fostering a major cultural change may be more difficult, said Josh Hartman, the senior adviser in the Pentagon's acquisition office, who in his previous job as a congressional staffer wrote the legislation establishing the ORS program.

"The biggest challenge they have in rapidly producing spacecraft is cultural," Hartman said. "It's getting people to understand what the business model and approach is about."

It may be a matter of making ORS tangible, said Air Force Maj. Scott Van Sant, the ORS lead at U.S. Strategic Command, Offutt Air Force Base, Neb.

"Culturally, DoD hasn't determined that small satellites can have a whole lot of utility," he said. "So we're going to struggle with that until we can actually produce something the [combatant commands] can use."

ORS' three tiers were set up in 2007 by Marine Corps Gen. James Cartwright, then the head of Strategic Command, and Ron Sega, then the Air Force undersecretary.

Tier 1 would be the first response to an emergency. Managers would have backup plans to tie together existing hardware - meaning backup satellites or systems on the ground - within hours or days.

If no Tier-1 solutions were available, managers would turn to Tier 2 options: plugging previously built instruments into small satellites and launching them within days or weeks.

Tier 3 would kick in if commanders needed a new type of capability. Engineers would deliver that capability within months to a year. Tier 3 spacecraft would have to cost less than $40 million to build and at most $20 million to launch.

Tier 1 programs are under way, Tier 2 capabilities are two to three years away, and Tier 3 capabilities will come online three to five years from now, Wegner said.

Demand for two distinct types of ORS satellites is becoming evident, said Joe Rouge, director of the Pentagon's National Security Space Office, which coordinates space policies across the Air Force, the other services and the National Reconnaissance Office, which manages spy satellites.

"The issue comes down to immediacy vs. future immediacy," Rouge said. In a crisis, commanders will want to respond immediately, but they'll also want more capability in the future. "By far, the biggest issue is balancing the creation of future capability vs. meeting urgent needs as identified by StratCom."

Wegner said he views efforts such as ORS Sat 1 and a previously planned series of five tactical satellites (TacSats) as a means of testing rapid development techniques while giving troops a taste of how ORS satellites might help them in the field.

ORS and the roughly 30 groups working on ORS initiatives are focusing on ways to apply the concept, he said.

Various spacecraft systems and subsystems must be standardized so engineers can install them into a spacecraft quickly, plug-and-play style. The spacecraft would have to be highly reliable through the temperature swings of orbit despite relatively little prelaunch testing. Think of plugging a camera or hard drive into the USB port on a home computer and then freezing it, cooking it and bombarding it with X-rays occasionally.

ORS engineers have had some success here, Wegner said. An Air Force Research Lab team assembled a modular spacecraft in four hours in August. A month later, ORS staff led a team that took six days to install a dummy spacecraft onto a small Falcon 1 rocket, the partially reusable boosters built by the California firm SpaceX for the operationally responsive satellite market.

Fast-build techniques are to be perfected under a new program called Chileworks after New Mexico's hot peppers combined with Lockheed Martin's Skunk Works and Boeing's Phantom Works.

Still, the U.S. aerospace industry and some of its customers in the military have yet to embrace ORS, several officials said. The space industry fears failure and is prone to test space hardware exhaustively, said Anil Rao, a University of Florida aerospace engineering professor.

"They talk about modular design. They say they want to do modular design," he said. "But they're afraid, in the end, of modular design."

Rao said he questions the space industry and military space establishment's willingness to go through the growing pains to make ORS a reality. "If they were willing to go through them, 10 years from now we'd be better off. We would have a much more malleable space industry. But now, everybody's very rigid."

Getting hardware on the shelf will take cooperation from an aerospace industry still getting to know responsive space. Fred Doyle, a Ball Aerospace vice president and general manager of the company's national defense business unit, said Ball is working with the Air Force to develop a flexible satellite platform designed to launch on various rockets with diverse payloads. But, he said, "We're primarily still trying to understand their true role and responsibilities, mission, priorities and funding."