Letter | Selling WGS Short on Performance
The SpaceNews article entitled “U.S. Air Force Expects Performance Boost on Newest WGS Satellites” [Dec. 3, page 5] reported on a Nov. 28 presentation on the status of the Wideband Global Satcom (WGS) program given at the Global Milsatcom conference. Unfortunately, the author of the article appears to have misinterpreted data extrapolated from other sources to draw the incorrect conclusions that WGS “has not been able to produce the amount of bandwidth expected of it” and generates “less than … the program’s baseline specification.”
SpaceNews referenced the WGS Selected Acquisition Report written by this office to derive capacity requirements and demonstrated performance. The report states the threshold and objective requirements for capacity as 1.2 gigabits per second (Gbps) and 3.6 Gbps, respectively, with demonstrated performance of 2.1 Gpbs. These performance values were confirmed by the chairman of the Joint Chiefs of Staff in the original WGS Operational Requirements Document.
A threshold requirement is the minimum acceptable value considered achievable within the available cost, schedule and technology at low-to-moderate risk. An objective requirement is the desired operational goal, if it can be achieved within program resources, and represents the maximum capability which would provide military utility. Programs are expected to meet the threshold requirements, and may pursue capability up to the objective only when the cost/risk/benefit trade provides a clear benefit to the government.
Since our first satellite launched in 2007, WGS’s demonstrated capacity of 2.1 Gbps remains well above the threshold requirement of 1.2 Gbps. The four on-orbit satellites are performing admirably in theaters around the world supporting global operations of the United States and six international partners. Because of its excellent performance, six more satellites are in various stages of production, including two scheduled to be launched in 2013. The WGS presentation at the Global Milsatcom conference explained that cost-effective enhancements to satellites 8 through 10 will provide even greater capacity, bringing these new satellites much closer to the objective of 3.6 Gbps.
Unfortunately, this article incorrectly characterized these exceptional satellites as failing to meet expectations or baseline specifications.
David W. Madden
The writer is director of the Milsatcom Systems Directorate at U.S. Air Force Space and Missile Systems Center.