WASHINGTON — The Pentagon’s acquisition czar assumed a key oversight role for an overbudget military satellite launching program because the U.S. Air Force office that previously held that responsibility had been vacated, the service said.

Frank Kendall, U.S. undersecretary of defense for acquisition, technology and logistics, took over the milestone decision authority for Evolved Expendable Launch Vehicle (EELV) program as part of a congressionally mandated review triggered by soaring costs. Milestone decision authority is military procurement terminology that refers to the bureaucratic power to determine whether a weapon system is ready to move to a new phase of development.

Speaking Sept. 5 at a defense conference here, Kendall said it would have been difficult to justify continuation of the program had he not assumed milestone decision authority. The Air Force does not have an acquisition executive in place with the credentials to exercise that responsibility, he said.

Air Force spokeswoman Maj. Tracy Bunko said EELV milestone decision authority would normally rest with Kendall by virtue of its dollar value, but that the responsibility had been delegated to the assistant secretary of the Air Force for acquisition. David Van Buren retired from that post March 31 and it has been vacant ever since. “When that position became vacant, milestone decision authority returned to Mr. Kendall,” Bunko said via email Sept. 6.

Kendall in July recertified the EELV program for continuation as required by law for weapon systems whose acquisition costs grow by 25 percent or more. In the recertification letter to the congressional committees that oversee defense spending, Kendall said the program’s projected cost over 150 launches had more than doubled, to nearly $70 billion.

Continuation of the EELV program is justified in part because no alternatives currently exist to launch satellites that are critical to U.S. national security, Kendall said. He also said the latest EELV cost estimates are reasonable, but at the same time noted that the program’s contract and management structure makes it difficult to find savings.

Denver-based United Launch Alliance (ULA), a Boeing-Lockheed Martin joint venture, is prime contractor on the EELV program and as such has a near-monopoly on U.S. government launch services. The company, created by the merger of the once-competing rocket manufacturing operations of its corporate parents, operates primarily under two EELV contracts, one for hardware and services and one for overhead and engineering work.

The Air Force in 2011 created a program executive officer to oversee the EELV program, which has long been under fire from U.S. lawmakers as well as ULA’s would-be competitors in the government launch services business.

Bunko, citing Kendall’s letter, said most of the EELV cost growth has been attributed to market forces that are beyond the program’s control. She said the Air Force will continue to work with the Office of the Secretary of Defense and Congress to keep program costs under control while introducing competition in the military launch business.

U.S. Rep. Michael Turner (R-Ohio), who chairs the House Armed Services strategic forces subcommittee, said he will continue to watch the EELV program closely. “I am confident the Air Force is developing a clear path forward for controlling costs and ensuring competition opportunities are available for those providers that can meet established mission assurance requirements to protect the warfighter and the taxpayer’s investment in multibillion dollar critical national security platforms,” he said in an emailed statement.