The Defense Department announced Tuesday that it would eliminate the selective availability feature on new Global Positioning System satellites. That decision coincides with the view expressed earlier this year by the National Space-based Positioning, Navigation, and Timing Advisory Board. The Pentagon stopped using the SA feature, which permitted satellite operators to intentionally degrade the GPS signal, in May 2000, but the advisory group believes that the continued inclusion of the SA feature generated international mistrust at a time when alternatives to GPS are emerging.
Celebrating 100 Years of Liquid-Fueled Rockets
March 11, 2026
March 16, 2026, marks 100 years since Dr. Robert H. Goddard launched the world’s first liquid-fueled rocket. Over the past century, new and ever more capable liquid-fueled rockets have literally propelled humanity into space. Why liquid-fueled rockets?