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FEATURE HISTORY OF TECHNOLOGY

A SPY
SATELLITE
YOU’VE
NEVER HEARD
OF HELPED
WIN THE
COLD WAR
The Parcae project revolutionized electronic eavesdropping

BY IVAN AMATO

21 JAN 2025 13 MIN READ  

NRO

I
N THE EARLY 1970S, the Cold War had reached a
particularly frigid moment, and U.S. military and
intelligence officials had a problem. The Soviet Navy
was becoming a global maritime threat—and the United
States did not have a global ocean-surveillance capability.
Adding to the alarm was the emergence of a new Kirov class
of nuclear-powered guided-missile battle cruisers, the largest
Soviet vessels yet. For the United States, this situation meant
that the perilous equilibrium of mutual assured destruction,
MAD, which so far had dissuaded either side from launching
a nuclear strike, could tilt in the wrong direction.

It would be up to a top-secret satellite program called Parcae

to help keep the Cold War from suddenly toggling to hot. The
engineers working on Parcae would have to build the most
capable orbiting electronic intelligence system ever.

“It was becoming obvious what the challenges were,” says

Lee M. Hammarstrom, an electrical engineer who over a 40-
year period beginning in the 1960s was in the thick of
classified Cold-War technology development. His work
included the kind of satellite-based intelligence systems that
could fill the surveillance gap. The Soviet Union’s expanding
naval presence in the 1970s came on the heels of its growing
prowess in antiaircraft and antiballistic missile capabilities,
he notes. “We were under MAD at this time, so if the Soviets
had a way to negate our strikes, they might have considered
striking first.”

A Parcae satellite was just a few meters long but it had four solar panels
that extended several meters out from the body of the satellite. The rod
emerging from the satellite was a gravity boom, which kept the orbiter’s
signal antennas oriented toward Earth. NRO

Reliable, constant, and planetwide ocean surveillance

became a top U.S. priority. An existing ELINT (electronic
intelligence) satellite program, code-named Poppy, was able
to detect and geolocate the radar emissions from Soviet ships
and land-based systems, but until the program’s last stages it
could take weeks or more to make sense of its data.
According to Dwayne Day, a historian of space technology
for the National Academy of Sciences, the United States
conducted large naval exercises in 1971, with U.S. ships
broadcasting signals, and several types of ELINT satellites
attempting to detect them. The tests revealed worrisome
weaknesses in the country’s intelligence-gathering satellite
systems.

That’s where Parcae would come in.

Even the mere existence of

the satellites, which would
be built by a band of
veteran engineers at the
U.S. Naval Research
Laboratory (NRL) in
Washington, D.C., would
remain officially secret
until July 2023. That’s
when the National
Reconnaissance Office
One of the big advances of the Parcae
declassified a one-page
program was a three-satellite acknowledgment about
dispenser that could loft three
satellites, which then functioned Parcae. Since its
together in orbit as a group. Seen
here are three Parcae satellites on establishment in 1961, the
the dispenser. ARTHUR COLLIER
NRO has directed and
overseen the nation’s spy-
satellite programs, including ones for photoreconnaissance,
communications interception, signals intelligence, and radar.
With this scant declassification, the Parcae program could at
least be celebrated by name and its overall mission revealed
during the NRL’s centennial celebration that year.

Aspects of the Parcae program had been unofficially outed

over the years by a few enterprising journalists in such
venues as Aviation Week & Space Technology and The Space
Review, by historians like Day, and even by a Russian military
advisor in a Ministry of Defense journal. This article is based
on these sources, along with additional interviews and
written input from Navy engineers who designed, built,
operated, and managed Parcae and its precursor satellite
systems. They confirm a commonly held but nevertheless
profound understanding about the United States during that
era. Simply put, there was nothing quite like the paranoia and
high stakes of the Cold War to spur engineers into creative
frenzies that rapidly produced brilliant national-security
technologies, including surveillance systems like Parcae.

A Spy Satellite with a Cosmic

Cover Name
Although the NRO authorized and paid for Parcae, the
responsibility to actually design and build it fell to the cold-
warrior engineers at NRL and their contractor-partners at
such places as Systems Engineering Laboratories and HRB
Singer, a signal-analysis and -processing firm in State
College, Pa.

Parcae was the third Navy satellite ELINT program funded

by the NRO. The first was a satellite called GRAB, about as
big as an exercise ball. GRAB stood for Galactic Radiation
and Background experiment, which was a cover name for the
satellite’s secret payload; it also had a bona fide solar-science
payload housed in the same shell [see sidebar, “From
Quartz-Crystal Detectors to Eavesdropping Satellites”]. On
22 June 1960, GRAB made it into orbit to become the world’s
first spy satellite, though there was no opportunity to brag
about it. The existence of GRAB’s classified mission was an
official secret until 1998.

A second GRAB launched in 1961, and the pair of satellites

monitored Soviet radar systems for the National Security
Agency and the Strategic Air Command. The NSA,
headquartered at Fort Meade, Md., is responsible for many
aspects of U.S. signals intelligence, notably intercepting and
decrypting sensitive communications all over the world and
devising machines and algorithms that protect U.S. official
communications. The SAC was until 1992 in charge of the
country’s strategic bombers and intercontinental ballistic
missiles.

The GRAB satellites

tracked several thousand
Soviet air-defense radars
scattered across the vast
Russian continent, picking
up the radars’ pulses and
transmitting them to
ground stations in friendly
countries around the
world. It could take months
to eke out useful
intelligence from the data,
which was hand-delivered
to NSA and SAC. There,
The Poppy Block II satellites, which
had a diameter of 61 centimeters, were analysts would examine
outfitted with antennas to pick up
signals from Soviet radars [top]. The
the data for “signals of
signals were recorded and
interest,” like the
retransmitted to ground stations, such
as this receiving console photographed proverbial needle in a
in 1965, designated AXGRX2800. NRO
haystack, interpret their
significance, and package the results into reports. All this
took days if not weeks, so GRAB data was mostly relevant for
overall situational awareness and longer-term strategic
planning.

In 1962, the GRAB program was revamped around more

advanced satellites, and rechristened Poppy. That program
operated until 1977 and was partially declassified in 2004.
With multiple satellites in orbit, Poppy could geolocate
emission sources, at least roughly.

Toward the end of the Poppy program, the NRL satellite team
showed it was even possible, in principle, to get this
information to end users within hours or even less by
relaying it directly to ground stations, rather than recording
the data first. These first instances of rapidly delivered
intelligence fired the imaginations, and expectations, of U.S.
national-security leaders and offered a glimpse of the ocean-
surveillance capabilities they wanted Parcae to provide.

How Parcae Inspired Modern

Satellite Signals Intelligence
The first of the 12 Parcae missions launched in 1976 and the
last, 20 years later. Over its long lifetime, the program had
other cryptic cover names, among them White Cloud and
Classic Wizard. According to NRO’s declassification memo, it
stopped using the Parcae satellites in May 2008.

Initially, Parcae launches

relied on an Atlas F rocket
to deliver three satellites in
precise orbital formations,
which were essential for
their geolocation and
tracking functions. (Later
launches used the larger
Titan IV-A rocket.) This
triple launching capability
was achieved with a
satellite dispenser designed
Originally designed as an
intercontinental ballistic missile
and built by an NRL team
(ICBM), the Atlas F was later led by Peter Wilhelm. As
repurposed to launch satellites,
including Parcae. PETER HUNTER PHOTO chief engineer for NRL’s
COLLECTIONS
satellite-building efforts for
some 60 years until his
retirement in 2015, Wilhelm directed the development of
more than 100 satellites, some of them still classified.

One of the Parcae satellites’ many technical breakthroughs

was a gravity-gradient stabilization boom, which was a long
retractable arm with a weight at the end. Moving the weight
shifted the center of mass of the satellite, enabling operators
on the ground to keep the satellite antennae facing
earthward.

The satellites generally worked in clusters of three (the name

Parcae comes from the three fates of Roman mythology),
each detecting the radar and radio emissions from Soviet
ships. To pinpoint a ship, the satellites were equipped with
highly precise, synchronized clocks. Tiny differences in the
time when each satellite received the radar signals emitted
from the ship were then used to triangulate the ship’s
location. The calculated location was updated each time the
satellites passed over.

A GRAB satellite was prepared for launch in 1960. Peter Wilhelm is standing,
at right, in a patterned shirt. NRO

Transmissions from the GRAB satellites were received in “huts” [left],

likely in a country just outside Soviet borders. In between the two banks of
receivers in this photo is the wheel used for manually steering the
antennas. These yagi antennas [right] were linearly polarized. NRO

The satellites collected huge amounts of data, which they

transmitted to ground stations around the world. These
stations were operated by the Naval Security Group
Command, which performed encryption and data-security
functions for the Navy. The data was then relayed via
communications satellites to Naval facilities worldwide,
where it was correlated and turned into intelligence. That
intelligence, in the form of Ships Emitter Locating Reports,
went out to watch officers and commanders aboard ships at
sea and other users. A report might include information
about, for example, a newly detected radar signal—the type
of radar, its frequencies, pulse, scan rates, and location.

The simultaneous detection of signals from different kinds of

emitters from a single location made it possible to identify
the class of the ship doing the emitting and even the specific
ship. This kind of granular maritime reconnaissance began in
the 1960s, when the NRL developed a ship surveillance
capability known as HULTEC, short for hull-to-emitter
correlation.

Early Minicomputers Spotted

Signals of Interest
To scour the otherwise overwhelming torrents of raw ELINT
data for signals of interest, the Parcae program included an
intelligence-analysis data-processing system built around
then-high-end computers. These were likely produced by
Systems Engineering Laboratories, in Fort Lauderdale, Fla.
SEL had produced the SEL-810 and SEL-86 minicomputers
used in the Poppy program.

These machines included a “real-time interrupt capability,”

which enabled the computers to halt data processing to
accept and store new data and then resume the processing
where it had left off. That feature was useful for a system like
Parcae, which continually harvested data. Also crucial to
ferreting out important signals was the data-processing
software, supplied by vendors whose identities remain
classified.

This analysis system was

capable of automatically
sifting through millions of
signals and discerning
which ones were worthy of
further attention. Such
automated winnowing of
ELINT data has become
much more sophisticated
in the decades since.

The most audacious

The SELX810 minicomputer was the heart requirement for the Parcae
of a data-processing system built to
scour the torrents of raw data from
system was that the
the Poppy satellites for signals of “intercept-to-report”
interest. COMPUTER HISTORY MUSEUM
interval—the time between
when the satellite detected a signal of interest and when the
report was generated—take no more than a few minutes,
rather than the hours or days that the best systems at the
time could deliver. Eventually, the requirement was that
reports be generated quickly enough to be used for day-to-
day and even hour-to-hour military decision making,
according to retired Navy Captain Arthur “Art” Collier. For
six years, Collier served as the NRO program manager for
Parcae. In a time of mutual assured destruction, he notes, if
the intercept-to-report delay was longer than the time it took
to fry an egg, national security leaders regarded it as a
vulnerability of potentially existential magnitude.

Over time, the Ships Emitter Locating Reports evolved from

crude teletype printouts derived from raw intercept data to
more user-friendly forms such as automatically displayed
maps. The reports delivered the intelligence, security, or
military meaning of the intercepts in formats that naval
commanders and other end users on the ground and in the
air could grasp quickly and put to use.

Parcae Tech and the 2AMinute

Warning
Harvesting and pinpointing radar signatures, though difficult
to pull off, wasn’t even the most sobering tech challenge.
Even more daunting was Parcae’s requirement to deliver
“sensor-to-shooter” intelligence—from a satellite to a ship
commander or weapons control station—within minutes.

According to Navy Captain James “Mel” Stephenson, who

was the first director of the NRO’s Operational Support
Office, achieving this goal required advances all along the
technology chain. That included the satellites, computer
hardware, data-processing algorithms, communications and
encryption protocols, broadcast channels, and end-user
terminals.

A key figure in the

From Quartz-
development of those user
Crystal Detectors
terminals was Ed Mashman,
to Eavesdropping
an engineer who worked as a
Satellites
contractor on Parcae. The
terminals had to be tailored
 according to where they
would be used and who would
be using them. One early
series was known as
Prototype Analysis Display
Systems, even though the
“prototypes” ended up
deployed as operational units.

Howard Lorenzen U.S. NAVAL Before these display systems

RESEARCH LABORATORY

The seed technology for the U.S. became available, Mashman

Navy’s entire ELINT-satellite story
goes back to World War II, when the
recalled in an interview for
Naval Research Laboratory (NRL) IEEE Spectrum, “Much of the
became a leading developer in the
then-new business of electronic data that had been coming in
warfare and countermeasures.
Think of monitoring an enemy’s from Classic Wizard just went
radio-control signals, fooling its
electronic reconnaissance probes, into the burn bag, because
and evading its radar-detection
system.
they could not keep up with
NRL’s foray into satellite-based the high volume.” The
signals intelligence emerged from a
quartz-crystal-based radio-wave intelligence analysts were still
detector designed by NRL engineer
Reid Mayo that he sometimes
relying on an arduous process
personally installed on the to determine if the
periscopes of U.S. submarines. This
device helped commanders save information in the reports was
their submarines and the lives of
those aboard by specifying when alarming enough to require
and from what direction enemy
radars were probing their vessels. some kind of action, such as
In the late 1950s, as the Space Age positioning U.S. naval vessels
was lifting off, Mayo and his boss,
Howard Lorenzen (who would later that were close enough to a
hire Lee M. Hammarstrom), were
perhaps the first to realize that the Soviet vessel to launch an
same technology should be able to
“see” much larger landscapes of
attack.
enemy radar activity if the detectors
could be placed in orbit. Lorenzen
was an influential, larger-than-life
To make such assessments,
technology visionary often known the analysts had to screen a
as the father of electronic warfare.
In 2008, the United States named a huge number of teletype
missile-range instrumentation ship,
which supports and tracks missile reports coming in from the
launches, after him.
satellites, manually plotting
Lorenzen’s and Mayo’s engineering
concept of “raising the periscope” the data on a map to discern
for the purpose of ELINT gathering
was implemented on the first GRAB which ones might indicate a
satellite. The satellite was a secret
payload that piggybacked on a high-priority threat from the
publicly announced scientific
payload, Solrad, which collected
majority that did not. When
first-of-its-kind data on the sun’s the “prototype” display
ultraviolet- and X-ray radiation.
That data would prove useful for systems became available,
modeling and predicting the
behavior of the planet’s ionosphere,
Mashman recalls, the analysts
which influenced the far-flung radio could “all of a sudden, see it
communication near and dear to the
Navy. Though the United States automatically plotted on a
couldn’t brag about the GRAB
mission even as the Soviet Union map and get useful
was scoring first after first in the
space race, it was the world’s first information out of it…. When
successful spy payload in orbit,
beating by a few months the first
some really important thing
successful launch of Corona, the came from Classic Wizard, it
CIA’s maiden space-based
photoreconnaissance program. would [alert] the watch officer
and show where it was and
what it was.”

Data overload was even more of a problem aboard ship or in

the field, so NRL engineers developed the capability to
deliver the data directly to computers onboard ships and in
the field. Software automatically plotted the data on
geographic displays in a form that watch officers could
quickly understand and assess.

These capabilities were developed during shoulder-to-

shoulder work sessions between end users and engineers like
Mashman. Those sessions led to an iterative process by
which the ELINT system could deliver and package data in
user-friendly ways and with a swiftness that was tactically
useful.

Parcae’s rapid-dissemination model flourished well beyond

the end of the program and is one of Parcae’s most enduring
legacies. For example, to rapidly distribute intelligence
globally, Parcae’s engineering teams built a secure
communications channel based on a complex mix of
protocols, data-processing algorithms, and tailored
transmission waveforms, among other elements.

The communications network connecting these pieces

became known as the Tactical Receive Equipment and
Related Applications Broadcast. As recently as Operation
Desert Storm, it was still being used. “During Desert Storm,
we added imagery to the…broadcast, enabling it to reach the
forces as soon as it was generated,” says Stephenson.

According to
Hammarstrom, Parcae’s
communications
challenges had to be solved
concurrently with the core
challenge of managing and
parsing the vast amounts
of raw data into useful
intelligence. Coping with
this data deluge began with
Over the course of a 40-year career in
national security technologies, Lee M. the satellites themselves,
Hammarstrom rose to the position of
chief scientist of the National which some participants
Reconnaissance Office. U.S. NAVAL
RESEARCH LABORATORY
came to think of as
“orbiting peripherals.”

The term reflected the fact that the gathering of raw

electronic signals was just the beginning of a complex system
of complex systems. Even in the late 1960s, when Parcae’s
predecessor Poppy was operational, the NRL team and its
contractors had totally reconfigured the satellites, data-
collection system, ground stations, computers, and other
system elements for the task.

This “data density” issue had become apparent even with

GRAB 1 in 1960. Those who saw the first data harvests were
astonished by how much radar infrastructure the Soviet
Union had put in place. Finding ways of processing the data
became a primary focus for Hammarstrom and an emerging
breed of electronic, data, and computer engineers working on
these highly classified programs.

Collier notes that in addition to supporting military

operations, Parcae “was available to help provide maritime-
domain awareness for tracking drug, arms and human
trafficking as well as general commercial shipping.”

Those who built and operated Parcae and those who relied
on it for national security stress that so much more of the
story remains classified and untellable. As they reminisced in
interviews that can’t yet be fully shared, engineers who made
this spy satellite system real say they had not been more
professionally and creatively on fire before or after the
program. Parcae, though a part of the Cold War’s prevailing
paradigm of mutual assured destruction, proved to be a
technological adventure that gave these engineers joy.

This article appears in the February 2025 print issue.

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ABOUT THE AUTHOR

Ivan Amato is an author and freelance writer based in South Orange, N.J.
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FEATURE HISTORY OF TECHNOLOGY

THE FORGOTTEN STORY OF

HOW IBM INVENTED THE
AUTOMATED FAB
Fifty years ago, a brash middle manager had a vision: a chip in a day

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The Project SWIFT fabrication line was based on sectors, as shown in this patent diagram of the system from 1973. Each sector contained in an enclosure
all of the wafer-processing equipment needed to accomplish a segment of the fabrication process between lithographic-pattern exposures. IBM/U.S. PATENT
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