WASHINGTON — The U.S. subsidiary of British small satellite specialist Surrey Satellite Technology Ltd. is angling to build low-cost replacements for a pair of aging commercial imaging craft that the U.S. government has relied on for almost a decade.

The primary U.S. imagery suppliers, DigitalGlobe of Longmont, Colo., and GeoEye of Dulles, Va., draw the bulk of their revenue these days from relatively new satellites built and launched with Pentagon funding help. But the companies continue to operate less-capable spacecraft that are well beyond their design lives: GeoEye’sIkonos and DigitalGlobe’sQuickBird satellites were launched in 1999 and 2001, respectively.

Kevin Little, director of business development at Surrey Satellite Technology-US (SST-US), said U.S. government agencies, as well as a host of commercial customers, would benefit from continued access to the type of imagery Ikonos and QuickBird provide.

Surrey Satellite Technology Ltd. of Guildford, England, has built 34 small satellites for various government and commercial customers since 1981, but only a few for the U.S. government. Sensing a burgeoning market for satellites in the several-hundred-kilogram class, Surrey in 2008 established SST-US in Englewood, Colo., to compete for U.S. business. SST-US now has 15 employees and has yet to capture any major U.S. government satellite contracts.

For a fixed price of about $35 million, SST-US could build an imaging satellite capable of collecting black-and-white imagery with 1-meter ground resolution and color imagery with 4-meter ground resolution, Little said in a Feb. 9 interview. The company could build a constellation of five such satellites for about $150 million, he said. 

Imagery from these satellites would be similar in resolution to what Ikonos now provides, but not as sharp as QuickBird imagery.

The U.S. government has not indicated it would like Ikonos and QuickBird to be replaced. GeoEye, in a November 2009 filing with the U.S. Securities and Exchange Commission, said it has no plan to replace Ikonos. DigitalGlobe continues to explore its options for follow-on systems but will not comment on any specific requirements for them, company spokesman Chuck Herring said Feb. 11. Little declined to say whether any potential customers, government or commercial, had expressed interest in the proposal.

The military would benefit from having a larger constellation of optical satellites because of the shorter revisit times they would provide, Little said.

“The advantage of a five-satellite or even [larger] constellation is you’re going to be able to image in a cloudy environment,” he said. “Those [satellites] chase each other every 20 minutes, and as the weather changes, there’s an opportunity for a cloud-free image with the higher the number of satellites you have.”

Surrey recently built the satellites for a similar constellation operated by the commercial firm RapidEye AG of Brandenburg, Germany, Little noted. The five-satellite RapidEye constellation, which features color imagery with 6.5-meter ground resolution, was launched in 2008 and collects about 4 million square kilometers of imagery per day. The cost to build the satellites and ground system was $150 million, Little said.

SST-US would build imagery satellites for the United States based on the same 150-kilogram satellite platform, Little said. The dishwasher-size satellites would be about one-fifth the weight of Ikonos and QuickBird, and thus an entire constellation could be launched atop a single rocket, or a single satellite could be launched as a secondary payload, he said.

The smaller size and lower cost relative to Ikonos and QuickBird would come at the expense of pointing agility. The SST-US design would point straight at the Earth, whereas Ikonos is capable of pointing up to 60 degrees in any direction and QuickBird can change its look angle by 30 degrees, according to their respective operators.

SST-US plans to have a U.S.-based satellite manufacturing facility fully staffed with 240 employees by 2012. A contract from the U.S. government to build satellites would enable the company to accelerate its domestic production capability, Little said.