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The Cold War’s Classified Skyhook Program: A Participant’s Revelations


B.D. Gildenberg

Skeptical Inquirer Volume 28.3, May / June 2004

Classified high-altitude, long-duration flights of huge Skyhook balloons, which often returned their secret payloads to the surface, began in 1947 and continued for several decades.
This secret Cold War program was the likely progenitor of many key aspects of UFO mythology.

I was busy calibrating instrumentation for top-secret Project Mogul in the spring of 1947. In retrospect, I was totally unaware of the project’s actual identity. My security clearance was for the lower rating of confidential. I was unaware of the project title for another forty-eight years, until 1995.

Welcome to the arcane world of classified Skyhook programs and Cold War intrigue. In this review, I hope to reveal many of those once-classified programs, how they generated UFO mythology, and why that relationship has not been fully addressed.

I write from a thirty-five-year professional career as a Skyhook balloon specialist and direct experience with most of the programs in these revelations. I was also an investigator for a special Project Blue Office and years later worked on the Pentagon Roswell report.

A Skyhook balloon provides constant-level performance at a predetermined altitude. It is usually constructed of special plastics and can lift tons of payload for durations of days or longer. The latter capability was once highly classified. Skyhook balloons were huge. The average size of those discussed in this article was double the six million cubic feet of the Hindenberg. Their diameters were about 300 feet with a flaccid length of 430 feet. Primarily cruising in the stratosphere, the balloons change color at high altitudes during sunrises and sunsets, while the Earth below is almost dark. These characteristics equate to a superb UFO generator.

It is therefore more than a coincidence that the birth of this vehicle in 1947 coincided with the origin of the twentieth century UFO epidemic. That epidemic was highlighted by the Roswell incident, with Project Mogul the prime seed. That relationship has already been detailed in a number of Skeptical Inquirer articles (for example, Thomas 1995).

The Skyhook Program

The prime launch site for Project Mogul was Alamogordo Air Base in New Mexico, west and therefore upwind of Roswell. The 1947 launches were in June and July, but there were initial UFO reports around the East Coast prior to the summer (Brookesmith 1995). These were preliminary test launches from New Jersey and Long Island.

There were also sightings in the summer of 1947 in the western and northwestern United States. A 1949 Air Force investigation (Trakowski 1949) could not correlate those sightings with Project Mogul, but the Air Force was unaware of a Navy program launching cluster balloons in Colorado that same summer. Coordination between branches of the military was limited in the years just following World War II. Accordingly, the dilemma of that 1949 report added fuel to a developing UFO mythology.

Clusters of weather balloons launched from both New Mexico and Colorado triggered reports of flying saucers sighted in formations throughout the West. They briefly preceded plastic Skyhook balloons, but their performance as constant-level vehicles was marginal.

An initial government coverup for Project Mogul saw an assembled crew not associated with the project launching a similar configuration, but without the classified payload. Newspapers were invited to the launch again at Alamogordo Air Base. Years later, as the Roswell legend resurfaced, UFO proponents denounced Project Mogul as a cover-up for their alien event.

At Alamogordo AFB headquarters, Mogul was listed as a guided-missile program. That represented a further cover-up procedure. The actual purpose of the project was stratospheric detection of distant nuclear bomb tests. Unknown to Roswell enthusiasts were classified programs that operated for decades afterward, based on Project Mogul technology.

One unclassified derivative was Project Blue Book, the Air Force investigation of UFOs. An initial sponsor was the Air Material Command, headquarters for Project Mogul. Blue Book originated in January, 1948, under the title Project Sign. Project Mogul prompted the initial development of a USAF Skyhook facility at Alamogordo AFB (today Holloman AFB). It was eventually governed by the Cambridge Research Laboratories in Massachusetts and became the prime USAF Skyhook launch site, still active today. Project Blue Book had outlying reporting offices throughout the country. Their function was to gather UFO reports and send them to the Blue Book main office at Wright Field, Ohio.

At Holloman AFB, the Blue Book office was situated in our Skyhook Balloon building. That choice was biased by the significant percent of reports generated by our relatively new vehicle. This office was also unique in that it, like the Wright Field Center, analyzed reports. I joined the Holloman Skyhook group in 1951 for a thirty-year tour and immediately became involved with Project Blue Book.

There was a more discrete reason for this special Blue Book role. In 1951, we became the primary center for unclassified Project Moby Dick. In at least one pro-Roswell book that project was erroneously dated 1947 and classified as secret (Randle 1994). Such misinformation contributes to the mythology of government cover-ups.

Rumors and Cover-ups

Project Moby Dick’s stated purpose was to study stratosphere wind trajectories, as defined via three-day Skyhook flights. After training for over a year at our location, crews and equipment moved to three West Coast sites for the operational phase. Although the announced purpose did result in final reports containing those stratospheric trajectories, there was actually a secretive phase. Moby Dick was in fact a cover-up for top-secret project WS-119L.

Beside the alphanumeric title, secret projects have secret names that vary for different phases. This program was called Project Gopher at our Alamogordo AFB launch site. It later accumulated titles including Grayback, Moby Dick Hi, Gentrix, and Grandson.

Even the WS prefix was a cover-up, since it was not a weapon system. The actual project goal was balloon reconnaissance of the Soviet Union. The entire subject is extensively covered in an excellent book by historian Curtis Peebles (Peebles 1991). Project Moby Dick was actually gathering trajectory data for Project Gopher, although the information also generated unclassified data for meteorological applications.

We flew five Gopher (WS-119L) test flights in 1951 and 1952 from our Air Force Skyhook Center. The payload was kept in a hanger during flight preparation under continuous armed guard. Outsiders noticed this and ensuing rumors eventually generated tales including a secret Project Aquarius. In Randle’s UFO Casebook (Randle 1989) he notes, “a possible Project Aquarius; Headquarters may be in Alamogordo with an important Branch in Montana.” In fact, we did have an auxiliary training camp in Montana. The mythology of Project Aquarius is nebulous but has something to do with an MJ-12 committee maintaining communications with Roswell aliens.

All this intrigue came to a head when the CIA suddenly showed up at our office and at launches. UFO reports peaked in 1952, as our local Skyhook activity increased from ninety-two hours the previous year to 694 hours aloft. Moreover, launches from the Moby Dick West Coast sites were commencing. Eventually they, along with additional sites in Missouri and Georgia, contributed 640 flights.

The CIA requested that we not identify most of those sharply increasing Skyhook reports. The strategy was to generate a UFO outbreak over the USA extending to the USSR when our WS-119L Skyhooks arrived there. Ironically, the ploy initially worked, since the Soviet Air Force could not intercept the first wave. They allowed their public to play our UFO game. The strategy ended after a few leaking Skyhooks were shot down and the payloads were exhibited, along with protests, to President Eisenhower.

Thus, complex interplay of Moby Dick, WS-119L, and UFO reports defined the unique role of our Blue Book office in that era. Since top-secret WS-119L was not declassified until more than thirty years later, that intrigue can only now be addressed.

Although initial phases of WS-119L were launched from Europe and Turkey, a final phase, WS-461L, was launched from the Pacific. There was a direct parallel to Moby Dick, where unclassified Project White Cloud launched Pacific flights to obtain trajectory data for WS-461L. In the April 1994 issue of Omni magazine, a retired airman proclaimed solid proof of UFO activity. He had glimpsed logs from the European NATO Command Center for 1958. They reported UFOs coming out of the USSR at 100,000 foot altitudes. That nicely described WS-461L flights cruising in from the Pacific Ocean launches.

The entire Skyhook reconnaissance program produced marginal data, but its recovery techniques phased into satellite programs. Moreover, the Soviets were so impressed they actually developed several high-altitude aircraft dedicated to intercepting our Skyhooks! In the 1960s, Premier Khrushchev developed a habit of banging his shoe on the table in protest at the UN. In one such case, he exhibited a WS-119L payload, perhaps with some of our trainees’ initials on it.

Late in 1952, I spent a month at Edwards AFB, California, to forecast three-day trajectories for Moby Dick flights, as specified in my travel orders. Forty years later, I discovered from Peebles’s The Moby Dick Project (Peebles 1991) that I actually had been working on a top-secret program called Flying Cloud, WS-124A!

Skyhooks were to be evaluated as a balloon bomber in the event of an actual war. Proposed payloads included nuclear warheads, but the program was abandoned as intercontinental ballistic missiles became viable.

UFO Mythology

There were a number of peripheral events associated with these programs. At Alamogordo AFB in 1952, we dispatched F-86 jet aircraft to see if they could intercept our Skyhooks at various altitudes. The exercise was designed to evaluate what Soviet interceptors might experience when our reconnaissance balloons arrived. The event was described in Timothy Good’s Above Top Secret (Good 1988), published thirty-six years later. It represents a classic example of how portrayals of classified military testing can become transformed over decades into something out of this world. Date and aircraft type were correct but the latter were described as trying to intercept an evasive UFO that featured hovering and accelerations up to 700 mph.

Alamogordo Air Force Base was renamed Holloman AFB in 1953. On October 27 of that year, we launched an unclassified payload. It failed to terminate at the scheduled twelve-hour flight duration, and, six days later, it was detected by the Royal Air Force over the Atlantic headed for London! This of course generated UFO hysteria (Good 1988). Newspapers announced it could not be a Skyhook since there was presently no such activity in Europe, but altitude and performance reports agreed with our vehicle’s capabilities. Ironically, British intelligence officers also knew that but would not disclose the object’s identity. They too were involved with the WS-119L program, and test flights were to be launched from Scotland. Yet this incident is still highlighted in UFO literature as a classic case for their cause.

We flew a few classified programs in the late 1950s and 1960s which included special flares at night from twenty-mile altitudes. That was a predictable UFO generator.

Philip Corso’s book The Day after Roswell (Corso 1997) contained many significant errors including movements of some of Wernher von Braun’s German scientists, who shared our building at Holloman AFB. Sixty pages were dedicated to a once-secret U.S. Army project for a lunar base called Project Horizon. Plans were initiated in 1959 but were finally cancelled because Project Apollo had exhausted space funds. The story was suspiciously infused with hints of alien activity on the Moon. That was interesting because that same year my Skyhook Center was flying a classified Army project, code named . . . Project Horizon! It had nothing to do with lunar bases and involved photographic studies of the horizon. The purpose was to obtain calibration information for guided missiles.

In 1967 and 1969, we flew ever more advanced, classified reconnaissance cameras. These cameras were huge, weighing from 6,000 to 8,000 pounds, and encased in ten-foot cylinders. They were tracked by several helicopters carrying armed military police to surround the payload after landing. With Roswell often downwind, this very likely contributed to that UFO story line, and time compaction is a vital ingredient in creating such myths and legends.

Skyhook incidents near to or on the ground, like this previous case, provoked more UFO tales than balloons at an altitude. There was a cluster of this type of event in the 1960s (Peebles 1994), which evoked much media coverage. It persists today as a hallmark UFO case, and features the most detailed witness descriptions.

One of those events had serious overtones, involving sensitive military sites, with no obvious revelations to this date. It is noted in Good’s book, Above Top Secret (Good 1988). “A metallic disc-shaped UFO with bright flashing lights moving slowly over the site. It stopped and hovered at 500 feet then the UFO climbed vertically and disappeared at high speed” (this was in March, 1967). The location was a Minuteman missile site at Minot, North Dakota. I became suspicious after reading this, aware of a top-secret Skyhook program in that era, with one launch site in the Dakotas. There were other descriptions that rather precisely identified the program, despite scattered inclusions of media mythology.

The program was Project Grab Bag, also called Sky Dipper or Cold Ash. Again, there was a cover-up unclassified program, Program Ash Can. Both programs involved sampling radioactive fallout debris in the stratosphere. After a brief Navy test sequence, Grab Bag, now under the USAF, became operational in 1956, extending briefly into the 1970s. Its highly classified signature was due to the fact that a final product involved establishing details of Soviet plutonium production. Even our Project Ash Can attracted more than the usual Skyhook attention, since parachute and payload were snatched in midair by USAF cargo aircraft. That prompted stories of aircraft being attacked by a UFO while the mother ship (the Skyhook) hovered high above.

Grab Bag was a special UFO generator. After stratospheric sampling, lifting gas was partially released through a valve in the apex of the Skyhook. The entire ensemble was thus lowered to within a few thousand feet of the ground. Then it released a parachute with the payload while the under-loaded balloon rocketed upward to eventually shatter. Since most of these activities occurred at night, Grab Bag generated probably the most detailed UFO events in the literature. For instance, “A conical shaped object descended from the sky. It hovered at an estimated 3,000 feet. A smaller UFO landed within fifty feet” (Brookesmith 1995).

That is a precise description of the basic Grab Bag profile. The Minuteman case with a UFO climbing vertically to disappear at high speed sounds very much like the under-loaded balloon zooming skyward to disappear as it self-destructed.

Project tracking included three helicopters. If the winds were light, the entire ensemble would be valved to the surface. Again, UFO reports clearly identified the process. “Floating red lights which moved over a highway and into a field at night. It appeared like a two-story building, with other lights grouped around it. The latter sometimes hover around the central object” (Fawcett and Greenwood 1984).

The payload did indeed have red lights. The other hovering lights were the helicopters. Just before landing the sample would be transferred to another container via a powerful centrifugal blower. That noise amplified the mystery. Occasionally the tracking crew would transfer the sample into metal cylinders, engendering even more strange noises in the dark. Other activity was also reported: “Radiation fields and other forms of energy have appeared to be directly connected with a hovering or landed UFO” (Brookesmith 1995). The radioactivity, although slight, was from the sample being transferred by recovery personnel to another container.

Readers may wonder why, after recovery, Grab Bag personnel would not have notified local authorities without disclosing classification. The answer is that proceedings were so classified that they could not identify their mission under any circumstance. The program was a natural for engendering mystery and a treasury of lucrative narratives for UFO folklore.

Meanwhile, at our Holloman AFB Skyhook Center, we continued to launch a variety of classified reconnaissance cameras, now with loads up to five tons. Again, there were tracking helicopters with armed military police (MPs). People in southern New Mexico were used to seeing military helicopters on various missions. However, we flew a number of reconnaissance camera missions in 1975 in northeastern New Mexico where military helicopters were seldom seen. This created some suspicion. “Unidentified helicopters” had also helped to amplify Grab Bag as a UFO generator, triggering later myths involving military helicopters.

There was an outbreak of mutilated cattle stories in Colorado and northeastern New Mexico in 1975. Strange helicopters were part of the scenario. The Albuquerque Journal reported “ghost copters” buzzing ranches (Peebles 1994). The presence of armed MPs onboard added to the frenzy. The FAA Area Coordinator announced an investigation of this outbreak but never revealed what it had found. The FBI also became involved with similar results. Both agencies had quickly discovered it was our highly classified program. Their “case closed” reaction is still highlighted today in government cover-up tales.

Clearly, secret Skyhook balloon programs magnified government cover-ups and engendered numerous UFO stories, sightings, and myths. Classified aircraft also contributed to UFO folklore during the Cold War. The U-2 reconnaissance aircraft followed WS-119L operations over the USSR. It triggered similar UFO reports, even while training in the U.S. However, unlike supersonic aircraft, Skyhooks remained within sight for long durations, landing with strange payloads, far from their origin.

It is important that all this activity be revealed. Project Grab Bag generated the most detailed descriptions of UFOs in the literature. Even relatively skeptical individuals might have wondered about those sightings, believing them to be too complex to dismiss. I hope these revelations provide a vital insight into what was “behind the looking glass” of secret Cold War activities.

The Pentagon published the first two detailed reports in 1995 (Weaver and McAndrew 1995), demonstrating how top-secret Project Mogul became the initial trigger for the Roswell mystery. Readers may wonder why that effort has not been repeated for once-classified events detailed in this article. Actually, it was only at the urging of a congressman, the late Steve Schiff of New Mexico, that the Pentagon began work on the Roswell affair. Having participated in the preparation of the final report (McAndrew 1997), I can reveal there was substantial resistance to the whole process. A number of times we thought the enterprise would be cancelled. It was only via last-minute intervention by the Secretary of the Air Force that the report was finally published. Many Pentagon authorities believed that the Roswell and UFO investigations in general were not worthy of distraction from more pressing matters of national importance.

Despite providing accurate hardware descriptions of the programs we have covered, some reports included stories of onboard aliens and other typical elements of UFO mythology such as stalled cars and skin burns. They were imitating numerous UFO witnesses with a tendency to repeat stories that preceded their own sightings.

We can deplore or marvel at the persistent thirst for otherworldly fantasies, but a sage in Elizabethan England had an apt comment that can categorize even contemporary mythology:

So full of shapes is fancy, that it alone is high fantastical.

—Shakespeare, Twelfth Night, Act I, Scene 1


B.D. Gildenberg

B.D. Gildenberg has had thirty-five years of continuous experience with Skyhook operations and an additional twenty-two years as a consultant. He has authored or co-authored articles in many skeptical magazines. His other background experiences include cryptography in the World War II Pentagon, work on the Pentagon Roswell reports, and involvement in astronaut tests prior to NASA. E-mail: