Protection of U.S. and friendly assets in space remains a top priority for the U.S. Air Force, though budget pressure may determine the pace of progress in this area, says Gen. William Shelton, Air Force Space Command chief.

Shelton is keenly interested in pursuing a follow-on to the Ball/Boeing Space-Based Space Surveillance (SBSS) satellite now surveiling objects in geosynchronous orbit. But he provided no firm plans for when an analysis of alternatives to look at options will be finished or an acquisition strategy developed to buy a new system. Plans will likely be revealed in the fiscal 2014 budget request being released April 10 by the White House.

“We have got to have a better ability to keep track of what is going on in geosynchronous orbit, and [this is] why SBSS follow-on is just a must-do,” Shelton told reporters during an April 9 briefing at the 29th National Space Symposium here. Shelton said he is particularly concerned about the fragility of plans to field only four Space-Based Infrared System (Sbirs) early missile warning satellites and Advanced Extremely High Frequency (AEHF) communications spacecraft. These are used in the event of a major national security crisis for the U.S., and an in-orbit failure or hostile attack would cripple U.S. responsiveness.

SBSS, launched in 2010, was designed with a gimbaled optical sensor to collect data on satellites orbiting in the crowded geosynchronous belt. Shelton says many lessons were learned in developing and fielding the pathfinder satellite. Estimated to cost just more than $800 million, the total price was closer to $1 billion. Suffering from sticker shock, the service punted on the follow-on program every year since then in favor of studies.

Shelton says the follow-on system needn’t be as “exquisite” as the pathfinder SBSS satellite. “We unfortunately let requirements creep get the best of us … We ended up building a pretty complex satellite. It was far more expensive than it needed to be.”

Improving space situational awareness — considered key to protecting U.S. and allied satellites — is a “very high priority” for Shelton.

Also in limbo are plans to announce a winner to design the future Space Fence, a series of ground-based radar sensors designed to track objects in space, Shelton says. Though a downselect was anticipated soon between Lockheed Martin and Raytheon, it is on hold. Money has been set aside for this contract, but Shelton says there has been debate about whether funding should be dedicated to higher-priority projects.

He has established a new Space Security and Defense Program office at Air Force Space Command to oversee activities in this arena. Though there was previously an office to handle this, he says this new organization will have a “more robust” role and the “broadest umbrella possible” in overseeing these activities.

Space control programs are largely classified, so much of the office’s work will not be visible. However, Shelton said he is satisfied with the level of work in this area.