Satellites are instrumental components in any nation’s defense strategy, providing monitoring and countermeasures capabilities against any long-range attacks. Satellites are often designed and constructed for relatively long operating lifetimes, such as a few years. But as recent reports on the Space Tracking and Surveillance System (STSS) satellites have shown, well-conceived satellites can far outlast their design lifetimes. Built by Northrop Grumman Corp. for the U.S. Missile Defense Agency (MDA), the STSS satellites had an initial four-year on-orbit design life but recently completed their 10th year of space operations.
This artist’s rendition shows how STSS satellites can track and destroy long-range warheads. The satellites, which were designed for an initial four-year stay in space, recently passed the 10-year mark in low Earth orbit (LEO). (Courtesy: Northrop Grumman)
The two “stereo” low-Earth-orbit (LEO) STSS satellites were launched on Sept. 25, 2009 on a Delta II launch vehicle from Cape Canaveral, Fla. They were placed in a 1350-km-altitude orbit with 58-deg. inclination and 120-min orbital period. The two satellites contain a sensor payload capable of detecting visible and infrared (IR) light. Designed as experimental space trackers for the Ballistic Missile Defense System (BMDS), the stereo satellites provide accurate tracking of midcourse of re-entry vehicles to BMDS interceptors and can perform stereo collection of birth-to-death missile flight information.
As Bob Mehltretter, vice president of military and civil space for Northrop Grumman explains: “STSS proved that space-based assets could significantly improve our nation’s missile defense capability and paved the way for future systems. Being able to track missiles from low Earth orbit allows threats to be engaged earlier in the process using existing interceptors.”