In some cases, cloud-computing vendors don't understand the scope of what government agencies need, said Chris Kemp, CIO at the National Aeronautics and Space Administration's Ames Research Center in California. Some cloud-computing vendors offer a small cluster of computers, while NASA often needs massive clusters to perform scientific research, said Kemp, speaking at forum on new IT approaches for the federal government.

"We operate at science scale, not enterprise application scale," Kemp said at the forum, sponsored by , a government IT discussion site, and Affirm, a nonprofit group focused on improving information management in the federal government.

Kemp and two other government IT managers expressed strong interest in cloud computing, with all three saying they are in some stage of experimenting with it or deploying it. Cloud computing will allow agencies to share computing resources and to cut energy use if done correctly, Kemp said.

The advantages of cloud computing "are so compelling, I don't think there's any going back," added Casey Coleman, CIO at the General Services Administration.

Cloud computing also can help government agencies get access to computing resources much faster than current requisition methods, Kemp said. "If we can provision infrastructure in the cloud and make that a five-minute operation and not a three-month operation," that's a major benefit, he said.