Defense Support Program
The Defense Support Program (DSP, engl. For Defence Support Programme ) is an early warning satellite program of the U.S. Air Force. It is the main component of the U.S. early warning devices against attacks by ballistic missiles.
The satellites are equipped with an infrared telescope to detect launching missiles and sensors that can detect nuclear explosions. During Operation Desert Storm, the DSP satellites were able to locate launches of Iraqi Scud missiles, and thus to provide advance warning to civilians and military units in Israel and Saudi Arabia.
All generations of the DSP satellites were developed by TRW ( Northrop Grumman since 2002 ) and built.
Technology
The cylindrical DSP satellites rotate around its own axis to scan the entire surface of the earth by means of the inclined built- Schmidt telescope of the infrared sensor. However, the satellites are not spin- stabilized, since the axis of rotation of the satellite must be always aligned perpendicular to the earth's surface. The satellites use an internal inverted flywheel to compensate for the angular momentum.
The primary satellite sensor consists of an array of lead (II ) sulfide infrared detectors.
The satellite, in contrast to most geostationary satellites not have its own rocket engine ( apogee ) to make the bullet in the geostationary orbit, so that the satellite from the launch vehicle must be stopped there itself. For the former satellites while a Titan -3 ( 23 ) C was used, and later the uprated Titan 34D Transtage. For the much larger satellites of phase 3, the Titan 4 rocket was used primarily with IUS upper stage, but could alternatively be made of the start with a space shuttle and IUS upper stage. For the last satellite came after the withdrawal of the Titan rocket, a Delta IV Heavy for use.
The ground control for the DSP satellites exerted by the 460th Space Wing at Buckley Air Force Base in Colorado. From there are some communication facilities both for North American Aerospace Defense Command ( NORAD ) and the Warning Center of the U.S. Strategic Command in Cheyenne Mountain in Colorado Springs. From these centers, the information is forwarded to various government agencies and the emergency services around the world.
History
The Defense Support Program was developed in the late 1960s as the successor of also working with infrared sensors MIDAS system. In contrast to the earlier, experimental system, the DSP satellites are in geostationary orbit, so they are always watching the same part of the globe.
Since the launch of the first DSP satellite on 6 November 1970, the system became the backbone of the U.S. Missile Early Warning System. Since the satellite constellation reached a near- global coverage with the exception of the polar regions with three satellites unnoticed missile launches had become virtually impossible. This included beside launched in intention to attack missiles and ballistic missile test with a satellite launch.
The DSP satellites have been developed in the course of the program steadily increased from initially 900 kg take-off mass and 2000 detector elements to 2380 kg take-off mass and 6000 detector elements. The planned lifetimes of the satellites were increased from 1.25 years to 5 years, with the majority of the satellites exceeded the planned service life by several times.
Other technological improvements were introduced in the course of time, such as To reduce signal processing on board the number of false alarms and detectors to protect the sensors against blinding laser attacks.
Since the phase II MOS / PIM - generation satellites can also be used in high elliptical orbits to allow an improvement of the warning against missile launches from the Arctic Ocean. In practice, this possibility has never been used.
As a follow-up project has been developed since the 1990s, the Space-Based Infrared System ( SBIRS ). This new generation of early warning satellites has instead of scanning sensors staring sensors with significantly faster reaction time.
Use
The first use in an emergency occurred during Operation Desert Storm, when DSP satellites could track the launches of Iraqi Scud short-range missiles and thus a warning to the population and the armed forces in Saudi Arabia and Israel was made possible.
Over the period of use proved that a number of other events except rocket launches can also be registered. Thus, the burning up of meteorites have been observed regularly with the system. Similarly, events which present a strong thermal radiation, registered. Thus, volcanic eruptions, forest fires and explosions can also be reported by the DSP satellites.
Generations of satellites
DSP - offs
Swell
- Air Force Space Command DSP Factsheet
- Major James J. Rosolanka, USAF, " Defense Support Program (DSP ) - A Pictorial Chronology 1970-1998 " (PDF file, 26.76 MB)