Defense Support Program The Defense Support Program ( DSP ) is a program of the U . S . Air Force that operates the reconnaissance satellite s which form the principal component of the " Satellite Early Warning System " currently used by the United States . DSP satellites , which are operated by the Air Force Space Command , detect missile or spacecraft launches and nuclear explosions using sensors that detect the infrared emissions from these intense sources of heat . During Desert Storm , for example , DSP was able to detect the launches of Iraqi Scud missiles and provide timely warnings to civilians and military forces in Israel and Saudi Arabia . The satellites are in geostationary orbit s , and are equipped with infrared sensors operating through a wide - angle Schmidt camera . The entire satellite spins so that the linear sensor array in the focal plane scans over the earth six times every minute . Typically , DSP satellites were launched on Titan IV B boosters with Inertial Upper Stage s . However , one DSP satellite was launched using the Space Shuttle Atlantis on mission STS - 44 ( November 24 , 1991 ) . The last one ( flight 23 ) was launched in 2007 aboard the first operational flight of the Delta IV Heavy rocket , as the Titan IV had been retired in 2005 . All 23 satellites were built by prime contractor Northrop Grumman Aerospace Systems , formerly TRW , in Redondo Beach , CA . The 460th Space Wing , with headquarters at Buckley Air Force Base , Colo . , has units that operate DSP satellites and report warning information , via communications links , to the NORAD and USSTRATCOM early warning centers within Cheyenne Mountain , Colorado . These centers immediately forward data to various agencies and areas of operations around the world . Air Force Space Command ' s SBIRS Wing at the Space and Missile Systems Center , Los Angeles AFB , California is responsible for development and acquisition of the satellites . History . The Defense Support Program replaced the 1960s space - based infrared Missile Defense Alarm System ( MiDAS ) . The first successful launch of MiDAS was May 24 , 1960 and there were twelve launches before the DSP program replaced it in 1966 . The first launch of a DSP satellite was on 6 November 1970 and since then it has become the mainstay of the United States ballistic missile early warning system . For the last 40 years they have provided an uninterrupted space - based early warning capability . The original DSP satellite weighed 2 , 000 pounds ( 900 kg ) and had 400 watts of power , 2 , 000 detectors and a design life of 1 . 25 years . Throughout the life of the program , the satellite design has undergone numerous improvements to enhance reliability and capability . The weight grew to 5 , 250 pounds ( 2 , 380 kg ) , the power to 1 , 275 watts , the number of detectors increased threefold to 6 , 000 and the design life has been increased to a goal of five years . The numerous improvement projects have enabled DSP to provide accurate , reliable data in the face of evolving missile threats . On - station sensor reliability has provided uninterrupted service well past their design lifetime . Recent technological improvements in sensor design include above - the - horizon capability and improved resolution . Increased on - board signal - processing capability improves clutter rejection . Enhanced reliability and survivability improvements were also incorporated . The 23rd , and last DSP satellite was scheduled to be launched on April 1 , 2007 , aboard a Delta IV Heavy rocket , but the launch was postponed until mid - August 2007 after two structural cracks were found in the metal launch table at pad 37B , caused by a fuel leak during testing . Further delays forced the launch back to November 11 , 2007 , when the satellite launched at 01 : 50 : 00 GMT ( 20 : 50 EST on 10 November ) . This satellite died in space sometime during 2008 , for reasons unknown . It is now adrift in geosynchronous orbit and remains a potential hazard to other craft . The Department Of Defense sent a MiTEx spacecraft to inspect DSP 23 sometime in 2008 . Another DSP satellite was lost in 1999 , after its Inertial Upper Stage failed following launch from a Titan 4 booster . DSP satellites will be replaced by the Space - Based Infrared System ( SBIRS ) satellites . The project was originally to have had a life of 25 satellites , but the last two have been canceled , mainly due to SBIRS . There were five major improvement programs prior to the current block : More recently , there has been some effort put into using DSPs ' infrared sensors as part of an early warning system for natural disasters like volcanic eruptions and forest fires . Limitations . The DSP constellation may have offered an excellent vantage point for an early warning system against state - centric threats such as missiles , but military analysts warn its ability to collect intelligence on non - state actors is severely limited .