Abstract
On November 6, 1970, the earth shuddered and the dark, morning sky lit up like an early dawn. In the bright orange light, spectators miles away could see the massive Titan III rocket slowly lift from its launch pad and lean toward the Atlantic Ocean as it began its long journey to the heavens. It was the blastoff of one of America's most secret satellites, accomplished in typical American style.
Throughout the week, as air force officials denied that any launch was planned, the sign on a local bank in downtown Cocoa, Florida, blinked its message on and off: “Spy Satellite Goes 5:47 A.M. Friday, Titan 3 Rocket.” Motels around Cape Canaveral, hoping to attract guests, proudly and publicly promoted the upcoming mission. “All one had to do was to go to dinner at the restaurant down the road,” recalled one former official, “and see all the visitors' faces, uniforms, and especially, raucous talk. The crowds on the beach on the night of the launch were quite large.” The next day, the New York Times declared, “Reliable sources disclosed that the 1,800-pound satellite … would provide roughly 30 minutes warning of approaching intercontinental missiles.” It was a very public sendoff for a very unusual satellite.
A century earlier, up and down the East Coast, soldiers and sailors stood atop tall forts and peered through spyglasses in search of invading ships. With the launch of the “secret” satellite that dark November morning, early warning moved into the space age. The nose cone on the rocket contained an oddly shaped, 1,800-pound spacecraft designed to flash an alert to American defense officials seconds after the launch of a missile or the explosion of a nuclear weapon. The long, expensive, and risky effort to give the nation a few minutes warning of impending doom is the subject of Jeffrey Richelson's comprehensive history of the Defense Support Program (DSP), America's Space Sentinels.
As Richelson, a senior fellow at the National Security Archives, tells it, the struggle to launch early warning satellites was as much one of bureaucracy as of science. In 1955, two years before the Soviet's launch of Sputnik, Rand scientists proposed detecting ICBMs “with a satellite-borne infrared search set.” The scientists determined that heat emitted by a rocket during takeoff and reentry could be detected by infrared equipment. This led to the development, by the Advanced Research Projects Agency, of the MIDAS (Missile Defense Alarm System) program, which envisioned placing a constellation of 10 early warning satellites into orbit as soon as July 1961. But to many in the Pentagon, the idea was more pie in the sky than spy in the sky. “There has been and continues to be strong opposition to the Operational Plans,” wrote Gen. Thomas D. White, the air force chief of staff. “Approval of the MIDAS plan is being delayed because of the doubt … in our ability to achieve necessary system reliability.”
“I always like to knock at exactly three a.m.”
“You should have called me sooner.”
Among the alternative concepts was a system involving 84 infraredequipped U-2 spy planes flying 3,000-nautical-mile missions around the periphery of the Soviet Union at up to 70,000 feet.
The MIDAS program got a boost from an unlikely source in 1960. That year Soviet Premier Nikita Khrushchev boasted of a series of ICBM tests, which were confirmed by telemetry intercepts. The missiles, launched from the Soviet Union, traveled 8,000 miles to the South Pacific, landing only 1,000 miles southwest of Hawaii. Khrushchev threatened to aim his missiles at Washington if the United States intervened militarily in Cuba. As a result, NORAD and the Air Defense Command pressed the air force to accelerate the MIDAS program as much as possible.
The goal of the massive effort, costing billions of dollars, was not to build a system that would save the nation or its population from nuclear annihilation. The best that was promised was that the satellites would add a brief 10 minutes to the notice provided by the early warning radar systems surrounding the Soviet Union—and far less notice of submarine-launched ballistic missiles. Instead, as Richelson points out, the extra warning would be useful only to save bombers for a counterattack. “The difference between what you do with 10 minutes warning, 20 minutes warning, 15 minutes or 25 minutes, is not really that great, I think,” said Pentagon official Harold Brown, who would later become defense secretary.
A string of failures, however, almost killed the program. One congressman, reacting to a 1963 Pentagon report to Congress, remarked that it sounded “like the kiss of death” for the program.
Success finally came in May 1963 with the launch of MIDAS 7. Operational for 47 days, the satellite was able to detect a series of planned missile tests from both the land and sea. The readout data “unequivocally established actual detection of each of the launches,” said a report. More success followed and the United States began building secret ground stations on opposite sides of the earth—one in central Australia and another near Denver. The interior locations were chosen to protect the signals flowing in and out of the stations from Soviet eavesdropping trawlers stationed off the coasts of the United States and other nations.
The November 1970 launch of the first DSP satellite was followed by three more. From their perch in geostationary orbit, 22,300 miles above the earth, the satellites were able to watch for missile launches and nuclear tests around most of the globe. The satellite's sensor package, which was able to spot a missile's plume against the backdrop of the earth, weighed about 700 pounds. Its infrared telescope, shaped like a 12-foot-long megahorn, was covered with 2,048 lead sulfide detectors that had the appearance of small, reddish mosaic tiles. Over the years, the red-eyes-in-the-sky detected Soviet missile tests at the Tyuratam launch site, sea-launched tests from the White Sea, French nuclear tests in the Pacific, and even explosions during Israel's Yom Kippur War in 1973. Eventually, the technology progressed so far that the DSP satellites could even monitor aircraft and spacecraft, as well as provide measurement and signature intelligence on a number of targets.
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More recently, however, the DSP satellite system has begun to show its age. According to Richelson, the air force told Congress in 1994 that the spacecraft were having difficulty detecting certain new classes of tactical missiles. Over the next decade, the Space-Based Infrared System (SBIRS) satellites will replace the DSP satellites. Among other new capabilities, the SBIRS satellite's improved eyesight will enable greater detection of Scud-class missiles.
The need to maintain early warning satellites was made clear as recently as last November, when Russia test-fired two nuclear-capable ballistic missiles from a submarine in the Barents Sea. The warhead sections successfully hit a Russian testing ground on the Kamchatka peninsula a short time later.
For three decades, the DSP satellites have stood their lonely watch in the coldest corner of the Cold War, locked in a stationary orbit far above the earth. In America's Space Sentinels, Richelson, who has in the past chronicled much of the darker side of the military space program, pays tribute to the thousands of nameless engineers and technicians who developed, launched, and ran America's nuclear-war sentry post in space.