Naval Research Laboratory engineers stand around a late model POPPY signals intelligence satellite, ca. 1970. The last POPPY satellite operated until 1977. (credit: National Reconnaissance Office)

A flower in the polar sky: the POPPY signals intelligence satellite and ocean surveillance

by Dwayne A. Day
Monday, April 28, 2008

The Lockheed Constellation was one of the most graceful propeller driven airliners to ever take to the skies, considered by many to be the pinnacle of the propliner in the 1950s, soon to be replaced by faster and larger jets. Long and slender, with a gentle curve to its back, like a greyhound, the “Connie” was big for its day and had long range. The US Navy had stuck a shark fin on its back and a squat dome on its belly with radars inside, called it the EC-121M Warning Star, and used it to spy on other countries.

On a cold January day in 1969 one of the Navy’s Warning Stars turned south over the Sea of Japan as the pilot slammed his throttles forward and tried to coax every bit of power he could out of the aging propeller-driven airplane. The plane had been on a routine mission, known as Beggar Shadow, to intercept North Korean radar and communications transmissions. But now the pilot was fleeing for safety from two North Korean MiG fighters that had been scrambled to intercept it, even though the plane was far out in international waters. The MiGs caught the Navy plane over a hundred kilometers from the North Korean coast and fired their cannons to blast it out of the sky. In a double stroke of bad luck, the Warning Star had carried a second crew for training, a total of 31 men, and they all died that day. The shootdown was proof, for those who had forgotten the lesson, that signals intelligence collection could be a very dangerous job indeed.

Such aircraft shootdowns were not uncommon during the Cold War. Neither were other incidents at sea that placed humans who were trying to gather sensitive signals at risk. But by the time of the Warning Star attack, satellites had increasingly taken over the duty of collecting the signals emitted by Soviet and other radars. The Warning Star attack helped to spur the Navy toward further development of its own signals intelligence satellite system, known as POPPY. Only now, over four decades later, is POPPY’s history slowly being revealed.

GRAB everything you can get

A decade ago the US government declassified the GRAB signals intelligence satellite program. GRAB was created in the weeks following Sputnik, when everybody in the military was thinking about new ways to capture the high ground—and the bundles of money that they expected to be hurled at space projects. GRAB was a small spacecraft, not much bigger than a basketball, with an official—and legitimate—cover story that it was intended to monitor solar radiation under the name SolRad. Five GRAB satellites launched between 1960 and 1961, although only two successfully achieved orbit. They produced real scientific results. But GRAB’s electronics also hid another mission: grabbing signals from Soviet radars and sending them down to ground stations ringing the Soviet Union. GRAB was built by the Naval Research Laboratory (NRL) for the National Reconnaissance Office (NRO), and both the National Security Agency (NSA) and the Air Force’s Strategic Air Command (SAC) were involved in analyzing and utilizing the signals it collected.

When GRAB was declassified in 1998 another secret signals intelligence satellite program known as POPPY was also slated to be publicly revealed. POPPY was the immediate follow-on to GRAB. But because of objections within the intelligence community, POPPY was not declassified until 2005. Exactly what those objections were has not been disclosed, although the most likely culprit was POPPY’s connection with ocean surveillance—detecting ships at sea.

Although it has been ten years since GRAB was declassified and two and a half years since the POPPY declassification, the amount of information released by the government on both programs has been relatively thin compared to other declassifications of satellite programs. In particular, the government has released very little information on satellite operations and technical design, indicating remaining government sensitivity about satellite signals intelligence capabilities. But recently, new information has been released on POPPY that adds some more details and provides a fuller picture of what this tiny cold warrior did.

From GRAB to POPPY

POPPY started out as a straightforward follow-on to GRAB, although exactly how it improved upon its predecessor is unclear. GRAB helped to demonstrate the densities of ground-based radars in the Soviet Union and produced a good first estimate of the geographic distribution of warning and air surveillance radars. It also identified several new Soviet radars. But GRAB’s major contribution was demonstrating that the Soviet air defense network included far more radars than SAC had expected, and this forced changes in SAC’s offensive strategy for fighting nuclear war.

POPPY’s improvements probably concerned things like the radar frequencies that the spacecraft scanned and its ability to precisely locate the target’s position on the Earth. GRAB intercepted all frequencies within a certain range from the territory that was visible below it and then sent this information to the nearest receiving station. The signals intelligence experts used various techniques to determine the location of the radar that was being intercepted. One technique used a limitation of the GRAB satellite, or more precisely, a limitation on the way that radars worked. Because Soviet air search radars rotated, their signals traveled out in a beam that swept around in a circle. But they did not travel straight up, creating a “hole” in GRAB’s donut-shaped coverage. Thus, if the signals experts detected a signal that vanished and then restarted again, they could determine that the satellite had flown overhead and the radar was located within that gap. Repeated orbits would allow them to pinpoint the location.

POPPY 1 launched on December 13, 1962, atop a Thor-Agena rocket. But the Agena’s engine did not shut down at the proper time, placing the satellite into an elliptical rather than circular orbit. Despite the less than ideal orbit the satellite provided useful information and was finally shut off 28 months later.

Six months later the Navy tried again. POPPY 2 was launched on June 15, 1963, into an incorrect elliptical orbit, but its perigee was so low that the atmosphere soon dragged the satellite down and it reentered after only six weeks of operation. On January 11, 1964, POPPY 3 was successfully launched into the proper orbit. POPPY 4 was launched on March 9, 1965, and it and subsequent satellites began lasting significantly longer in orbit than their predecessors. The POPPY ground station component was operated by the Naval Security Group under the designation SISS ZULU and included several fixed facilities around the world.

Hunting the ABM

In 1962 something occurred during one of the satellite missions that remains classified to this day. Apparently it involved an important signal that was not detected until much later. GRAB was a “bent pipe” system that instantly relayed the signals that it collected down to the ground without recording them for later playback, and POPPY probably used the same approach, at least initially. But the ground stations only recorded the received transmissions and did not process them. The recordings were then physically shipped back to the United States, but delays in processing could last up to three months. As a result, the Naval Security Group ordered its field sites to immediately report unusual signals, transmitting this information back to the United States ahead of the normal delivery of magnetic tapes, so that the NSA could begin assessing new radar signals much more quickly. POPPY benefitted from this new approach.

In mid-1966 the Johnson administration began pressing the intelligence community to locate the signals from anti-ballistic missile (ABM) radars. By this time POPPY 5 was nearly complete, scheduled for a February 1967 launch. But an NRL official asked for permission to delay the launch and modify the satellite to improve collection of ABM radar signals. This required equipment better able to detect the signals, more overlap in the suspected ABM frequency ranges, and upgrades to the ground system and recorders to improve quality. The head of the NRO granted the extension and NRL redesigned the satellite. POPPY 5 was launched on May 31, 1967, and stayed operational for a long period of time.

In addition to the ABM mission, POPPY also apparently had a role in detecting and monitoring Soviet space tracking radars—in other words, the same radars that were monitoring POPPY as it flew overhead. In fact, a significant portion of the American satellite signals intelligence effort in the 1960s was devoted determining the Soviets’ ability to spot American satellites overhead and possibly attack them. GRAB and POPPY continued to target primarily land-based emitters of interest to the US Air Force through the 1960s.

Hunting the Red Navy

From a bureaucratic standpoint, POPPY was unusual—it was a Navy program that primarily benefitted other government agencies. The Air Force and NSA used POPPY’s data more than the Navy. But by the late 1960s several things happened that caused Navy officials involved with POPPY to ask if it could also serve naval needs.

In June 1967 the intelligence ship USS Liberty was attacked by Israeli warplanes. In January 1968 the intelligence ship USS Pueblo was seized by North Korean naval forces and its crew held captive. And in April 1969 the Navy EC-121M Warning Star was shot down by a North Korean fighter jet. A lot of US Navy personnel lost their lives in these incidents. Whereas the Soviet Union could generally be expected to act with some restraint regarding American intelligence collectors operating on the Soviet periphery, other nations were not so predictable. The Navy faced the difficult option of having to provide protection for its intelligence monitoring systems, or of migrating at least some of their functions to safer platforms, such as satellites.

Those events highlighted the dangers of human involvement in collecting signals, but there had already been a push within the naval community to expand the use of satellites. In 1967 a classified report suggested that the NRO should consider using satellites to track hostile ships at sea. POPPY had already produced a few intercepts of Soviet ships at sea, but had never been specifically tasked with this mission. Soon the Navy began to experiment with POPPY. The details of these experiments remain classified, but they probably involved using American ships as test targets and determining POPPY’s ability to detect and possibly track them at sea. However, technical problems with the satellite made the tests inconclusive and this undercut the argument for using these vital assets for a new mission.

By December 1967 an experimental program involving POPPY, apparently directed against the Soviet Fifth Eskadra Fleet in the Mediterranean (based in the Black Sea), began to produce results and the Navy began work on a concept paper that outlined a plan for using satellites to locate hostile naval forces. By spring 1969 this proposal had worked its way up the chain of command. Adapting POPPY to the new mission would significantly increase its cost. But the NSA produced a report that compared system productivity to cost and demonstrated that productivity was rising far faster than cost. The system had also improved targeting information instead of simply providing area reports of intercepted signals.

In June 1969 General Andrew Goodpaster, who was then the commander of US forces in Europe, formally requested all-source intelligence support to locate Soviet units of the Mediterranean squadron. The Soviet Navy had increased its operations in the Med, which had concerned NATO officials. Goodpaster’s formal request now provided the high-level justification for turning the POPPY experiments into a regular program for conducting ocean surveillance from space.

It is unclear if Goodpaster was prompted to make his request because he was aware of POPPY’s newly-developed capabilities. But the Mediterranean also had another feature that made it more suitable to early ocean surveillance efforts—it was surrounded by land. This meant that POPPY would be in range of American military facilities in places like Italy and Libya during its transits over the Med. It is unclear if these early efforts also included putting receiving antennas on US naval vessels, but considering that the early GRAB ground stations were relatively small trailers, and it was common to equip ships as small as destroyers with trailers full of signals intelligence collection equipment, it seems likely that a POPPY collection capability was tested at sea relatively early in the development of its ocean surveillance capability.

From POPPY to PARCAE

POPPY 6 was launched on September 30, 1969, and replaced POPPY 5 as the primary in orbit collector. POPPY 6 had several improvements, including a wider frequency range. POPPY 7 was launched on December 14, 1971 and operated until August 1977. But by this time it was a mature system that was being overtaken by newer satellites.

By late 1971 the POPPY satellites in orbit were showing their age. POPPY 5 was near the end of its lifetime, while POPPY 6 had suffered some degradations. But a follow-on system was apparently already in the works. Known as PARCAE, with the unclassified cover designation White Cloud, part of the Naval Ocean Surveillance System (or NOSS), this program remains classified. Each PARCAE launch placed three satellites into orbit, flying as a constellation. Using three satellites probably increased the system’s ability to precisely locate targets because the satellites could now take multiple bearings on a target instead of only one, and also cover more area for a longer time. This was more important for the ocean surveillance role, as radars on ships would not sit still for the satellite to identify their location. PARCAE satellites were launched aboard Atlas rockets throughout the 1980s before being replaced in the 1990s by an upgraded system using the Titan 4. Today a two-satellite descendent of this system is launched aboard Atlas rockets.

Answers and more questions

The new revelations about POPPY raise some interesting questions. During the 1960s the Air Force had its own series of signals intelligence satellites, commonly referred to as “ferrets”. These had several distinct classes and subclasses and were launched in significant numbers throughout the decade—many more of these ferrets were placed in orbit than POPPY satellites. According to a newly declassified history of American cryptology, the Air Force’s ferrets were intended to support the Strategic Air Command’s Single Integrated Operational Plan (or SIOP), a bureaucratic euphemism for its plan for global thermonuclear war. By the early 1960s there was a rough division of labor between the GRAB/POPPY satellites and the Air Force’s ferrets—the Navy satellites collected general overall intelligence data on emitters in the Soviet Union, looking for new and unusual signals, whereas the ferrets focused on specific types of emitters, presumably to assist the Air Force in developing methods of jamming them.

Clearly the two systems had some overlap. When US intelligence officials became concerned about Soviet ABM capabilities in 1966, the satellite operators responded in different ways. Whereas the launch of POPPY 5 was delayed so that it could be altered to search for these new signals, the Air Force accelerated a ferret satellite program that was apparently already in the works, but it is unclear how these two efforts worked together.

Only the outlines of this relationship are sketched out and none of the details have been released. Whereas POPPY has at least been described in official histories and government press releases in general terms, the Air Force program has never been described at all, and knowledge of it comes from sporadic and disjointed document releases primarily from the late 1950s and early 1960s. These declassified documents have provided some tantalizing clues, however. For instance, both declassified documents and a government history have revealed that the Air Force first started experimenting with adding communications interception capabilities to its satellites in the early 1960s, and later developed this into a dedicated high-altitude system known as CANYON.

Another question concerns the other payloads that were launched alongside POPPY. The POPPY satellites themselves were small and each POPPY launch included several other satellites, some of them apparently entirely scientific or engineering projects. But until the recent declassification of information, most observers had assumed that POPPY was a multi-satellite system, like its successors. Could these other satellites have been other signals payloads? Radiation detectors? Something associated with tracking submarines? Or something even more unexpected?

Unfortunately, given the incredibly slow pace of declassification on these programs, those questions may remain unanswered for a long time to come.

Dwayne Day is currently writing a history article on POPPY for Spaceflight magazine. He would appreciate any information people are willing to share about it, and is also interested in information on Soviet naval operations in the Mediterranean in the 1960s. He can be reached at zirconic1@cox.net.

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