Science and Technology News

Monday, June 29, 2015

DSP satellites: bell ringers for national security

by Airman 1st Class Samantha Meadors
460th Space Wing Public Affairs


6/17/2015 - BUCKLEY AIR FORCE BASE, Colo.-  -- Since the early 1970s, the Defense Support Program has been the backbone of the U.S. ballistic missile early warning system.

This once classified satellite first launched in 1970 providing strategic surveillance with an infrared capability to detect long-range ballistic missile launches.

The mission of the DSP satellite is to detect missile launches using its infrared telescope that recognizes heat against the Earth's surface.

"In 1991, there were 12 foreign ballistic missile programs in the world," Wagner said. "Today over three dozen countries openly acknowledge a ballistic missile program and we have seen the catastrophic effects when these countries use ballistic missiles against each other or even against their own people. These missiles are increasingly lethal and mobile with more reliable, accurate and effective guidance systems. Technology enabled smaller, faster, more accurate, more storable, and inherently more deployable missiles with longer ranges."

During Operation Desert Storm, the growth of nations with tactical ballistic missile capability increased and DSP began to support troops in the Persian Gulf War. After detecting Iraqi Scud launches and providing timely warning to downrange users, DSP began to be used for tactical detection as well.

Scientists are currently in the process of developing methods to use the satellite as part of an early warning system for natural disasters like volcanic eruptions and forest fires.

The DSP constellation was first put in place to address the missile threat posed by the former Soviet Union.

"To understand and counter the threat of a surprise nuclear attack against the United States, we looked to air and then space because we truly needed global reach to see deep into the Soviet Union," said Col. John Wagner, 460th Space Wing commander.

"This was at a time when Soviet missile power was in our faces daily - particularly after the launch of Sputnik."

The early warning system took 15 minutes to provide warning of ballistic missile attack, so national priority was placed on the space-based system known as the Missile Defense Alarm System.

MIDAS was the first infrared detection technology that later became the basis for the DSP.

However, it took millions of taxpayer dollars and nine failed test flights before MIDAS 7 achieved the planned circular orbit in 1963. Since then, the DSP has been used to protect the U.S. and its allies from smaller and faster threats.

"After these initial MIDAS hard lessons, we enjoyed over 40 years of success with DSP," Wagner said. "This program was the first to use mercury cadmium telluride -- the material of choice for today's infrared sensors. Today's DSP spacecraft accommodates 6,000 detectors, uses 1,274 watts of power, weighs 5,200 pounds and is roughly the size of a Greyhound Bus."

The DSP satellites orbit the earth approximately 22,000 miles over the equator. The current DSP spacecraft is more survivable than its predecessors, lasting much longer than designed. It was originally intended to last 30 years, but has exceeded its lifespan over 15 years.

The DSP will eventually be replaced by the Space-Based Infrared System. SBIRS is composed of highly elliptical orbit and geosynchronous Earth orbit satellites.

The satellites' extreme accuracy and precision are designed to deliver timely and precise warning for missile launches to the U.S. government and allies.

"Imagine you're on a bus," said Col. Michael Guetlein, Remote Sensing Systems Directorate program director. "You're 22,000 miles away. You're moving 6,000 miles an hour. You're swinging a 1,000 pound telescope left and right at 10 times a second, 100 percent accuracy, and I want you to do that for 10 years. I want you to be looking down at the earth and I want you to pick out any heat event on the entire face of the earth.  And I want you to discriminate that event from the background. I want you to be able to tell me, is it a missile launch or is it a reflection off the ocean surface?"

That's what our satellites are out there doing, he added.

The SBIRS constellation falls under the Overhead Persistence Infrared program. The constant surveillance of the satellites keeps the U.S. and its allies safe.

"OPIR is not in our face, but it's the one thing that's keeping us safe on a day-to-day basis," Guetlein said. "It is the cornerstone of nuclear deterrence."

(Information from www.losangeles.af.mil and the Air Force Association Mitchell Institute Friday Space Group Seminar "Space Support to the Warfighter" was used in this article)

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