The Air Force completed on-orbit checkout of HEO-3, the third Space Based Infrared System sensor built for a US intelligence satellite operating in highly elliptical orbit, announced service officials on Monday. “I am extremely proud of the hard work and perseverance of the launch team, the operations team, and the countless other professionals whose dedication to the warfighter made this success possible,” said Lt. Gen. Samuel Greaves, commander of the Space and Missile Systems Center, the Air Force’s space acquisition arm, at Los Angeles AFB, Calif. “This sensor is a critical component of the on-orbit constellation of missile warning sensors, and enhances the combined constellations of Defense Support Program and SBIRS satellites,” he said. HEO-3 is a sophisticated infrared scanning sensor. It’s been in space since last year, resident on a spacecraft over the northern hemisphere, said the officials. HEO-3 is meant to replace HEO-1, which has been operating on orbit for years. HEO-2 is also functioning on orbit, along with GEO-1 and GEO-2, two SBIRS satellites in geosynchronous orbit. Both of them have a scanning sensor and a staring sensor. (See also When Staring is Proper.)
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?