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Defense Support Program

The Defense Support Program (DSP) satellites provide early warning for Intercontinental Ballistic Missile launches. This once classified satellite, now known as DSP, became the first of many to be launched over the next 30 years. It uses infrared detectors that are capable of sensing heat from missile plumes against the cooler background of the earth. Since 1970, the DSP has been a critical component of the North American Aerospace Defense Command’s (NORAD) Tactical Warning and Attack Assessment System.

The satellites orbit the earth approximately 35,780 kilometers over the equator. The DSP constellation is operated from the Space Based Infrared Systems (SBIRS) Mission Control Station (MCS) at Buckley Air Force Base, Colo. The Defense Support Program is managed by the Infrared Space Systems Directorate at the Air Force Space and Missile Systems Center at Los Angeles Air Force Base, California.

DSP Evolution

The Defense Support Program grew out of the successful 1960s space-based infrared Missile Defense Alarm System known as MIDAS. The first successful launch of MIDAS was May 24, 1960. Between 1960 and 1966, 12 MIDAS launches deployed four different types of increasingly sophisticated sensors -- leading the way to the development, launch and use of DSP.

On November 6, 1970, the U.S. Air Force launched a classified satellite on a Titan IIIC rocket from Launch Complex 40 at Cape Canaveral Air Force Station, Fla. This was the first of many DSP satellites to be launched over the next 30 years.

In response to the evolving threats, DSP has undergone five major upgrades that allow it to provide more accurate and reliable data to the warfighter. For example, the addition of a medium wavelength infrared capability has provided enhanced missile warning mission utility. This upgrade marked the first space sensor application of mercury cadmium telluride infrared sensors -- the material of choice for today's infrared sensors. The current DSP spacecraft is more survivable than its predecessors, accommodates 6,000 detectors, uses 1,274 watts of power and weighs 5,200 pounds.

Phase I, 1970-1973, 4 satellites
Phase II, 1975-1977, 3 satellites
Multi-Orbit Satellite Performance Improvement Modification (MOS/PIM), 1979-1984, 4 satellites
Phase II Upgrade, 1984-1987, 2 satellites
DSP-1, 1989 - present, 9 satellites launched to date

Launches and Satellite Data

DSP has a history of launching atop Titan III and IV family of launch vehicles (to include the Titan addition of the Solid Rocket Motor Upgrade) with one exception to date. DSP-16 was launched aboard NASA's Space Shuttle Atlantis in November 1991. The most recent launch, DSP-22, was carried into geosynchronous orbit by Lockheed Martin's Titan IVB launch vehicle and the Boeing's Inertial Upper Stage in February 2004.

The 23rd and final DSP satellite launched in December 2007. DSP-23 was the first operational satellite to launch atop Boeing's Delta IV Heavy Evolved Expendable Launch Vehicle (EELV).

In recent years, scientists have developed methods to use DSP's infrared sensor as part of an early warning system for natural disasters like volcanic eruptions and forest fires. In addition, researchers at The Aerospace Corporation have used DSP to develop portions of a hazard support system that will aid public safety in the future.

DSP Overview

Primary mission: Strategic and tactical missile launch detection

Contractor team:
Northrop Grumman Space Technology and Northrop Grumman Electronic Systems

First Deployed: November 6, 1970

Last Launch: February 14, 2004

Final Launch: December 2007

Current Status
Though many of these satellites were launched, there are only five that are optional as of late Spring of 2013. They were launched in the mid- to late-80s, and three function while the other two serve as backups. The satellites feed information to bases and control centers all around the world.

Recently, the United States looks to phase out the use of DSP and replace it with a system called Space-Based Infrared System-High (SBIRS-High) that more conducive to U.S. missile defense. The new system would consist of a network of five satellites in geosynchronous earth orbit, two sensors on host satellites in highly elliptical orbit, and associated fixed and mobile ground stations. SBIRS-High will provide missile warning information and support the missile defense, technical intelligence, and other military purposes.