Last year, The War Zone published a piece exploring a bizarre, unexplained, superweapon-like phenomenon referred to as the “Dome of Light” associated with launches of the Soviet Union’s RSD-10 Pioneer intermediate-range ballistic missile, also known as the SS-20 Saber, in the 1980s. Now, we have obtained previously classified intelligence documents that show U.S. intelligence analysts were equally perplexed by these rapidly expanding walls of light, which could have been intended as a countermeasure against early warning satellites and missile defense systems. They look to have been concerned about it becoming a feature of other Soviet ballistic missile launches, as well.
The War Zone received the documents, which the Air Force’s Foreign Technology Division (FTD) produced, through a Freedom of Information Act request. FTD was established in 1961 as a component of Air Force Systems Command and quickly became the service’s premier Foreign Materiel Exploitation (FME) unit, charged with analyzing and evaluating foreign aerospace technology, including various flyable and non-flyable foreign aircraft. FTD was notably responsible for maintaining a working fleet of Soviet bloc and Chinese-made combat jets, which were later turned over to the storied and secretive 4477th Test and Evaluation Squadron, better known as the Red Eagles, at Tonopah Test Range Airport, which you can read more about in this past War Zone piece.
FTD, which has since evolved to become part of the Air Force’s present National Air and Space Intelligence Center (NASIC), was the go-to entity within the service to try to explain the Dome of Light, which was also referred to in some of the documents simply by the abbreviation DOL. A heavily redacted section of one 1986 report describes the basics of the phenomenon as follows:
“Although reports differ, most observers describe the phenomenon as a small white sphere on the horizon that expands uniformly outward and upward while maintaining its dome-like shape. It is initially opaque, but as it expands it becomes transparent, and the stars can be seen through the center of the dome. As it begins to fade, the outer boundary remains brighter forming a rainbow-shaped arc. At full extent it has been reported as being tremendously large, filling more than half of the sky. Approximate calculations [redacted] indicate is is on the order of 1,900 km [approximately 1,180.6 miles] wide, with its center 1,000 km [approximately 621 miles] high. Most Domes of Light are visible for around 20 minutes but events lasting up to 100 minutes have been reported. In almost all cases the Domes of Light have been seen while observers were in darkness or twilight [redacted]”
This fits with the first-hand account of the Dome of Light that Robert Hopkins, a veteran Air Force pilot and author of The Boeing KC-135 Stratotanker: More Than a Tanker, who flew the RC-135S Cobra Ball missile tracking aircraft, among other types, shared with The War Zone last year.
Hopkins described what he saw in 1988 as follows:
“As we looked for traffic, we noticed what appeared to be a translucent, milky white wall moving from the left, over the USSR, to the right, toward the Northern Pacific Ocean. It covered the entire sky from ground level to as far up as we could see looking out the front windows of the airplane. It moved very quickly—far faster than crossing airplane traffic—and rapidly approached us. The wall of light passed across our flight path and then continued eastward, leaving the empty and dark night sky in its wake. Our programmed turn time arrived and we began our bank to the left to collect on the RVs. Once we rolled out southbound the wall of light was no longer visible to the east.”
It’s not clear when the Air Force, or any other branch of the U.S. military or element of the Intelligence Community, first encountered the Dome of Light or how many total instances American analysts and other personnel observed or were otherwise aware of. However, the unredacted portions of FTD’s 1986 report describe a relationship between the phenomenon and the road-mobile RSD-10/SS-20 intermediate-range ballistic missile (IRBM).
First deployed by the Soviets in 1976, this was that country’s most advanced IRBM design, with the final versions having a range of 4,700 miles and up to three Multiple Independently Targetable Reentry Vehicle warheads, or MIRVs.
While FTD saw a clear link between the RSD-10/SS-20 and the Dome of Light, its analysts, scientists, and engineers struggled to define exactly how the two were related. Every recorded instance of a Dome of Light at the time the 1986 report was written had been associated in some way with an RSD-10/SS-20 launch, but not all launches of this missile featured the phenomenon. On top of that, in some cases, the light show appeared before there was a launch, while other sightings were reported to have occurred after the missile blasted off.
“To date. no satisfactory explanation exists that does not conflict with some portion of the reported observations,” the 1986 FTD report states bluntly. “Speculations range from a naturally occurring phenomenon as a result of venting unused rocket fuel to the release of ion clouds to simulate a post-nuclear attack environment for the purpose of communication experiments.”
“Observations of the dispersion can then be used to calculate physical properties of the upper atmosphere such as density, temperature, and particle flow rates,” the unredacted portions of the report continue, offering additional details about the ion cloud theory. “These experiments differ from the reported Domes of Light observations in several respects, most importantly in appearance, size, and observed duration. The domes do not appear to contain charged particles since there is no striation or tendency for the particles to follow the magnetic field lines as in ion release experiments. Additionally, the domes are much larger and are visible for a longer period of time than any known ionization experiment.”
A passage detailing a “second explanation” is entirely redacted. However, an uncensored portion of the report that follows refers to a computer model a Russian mathematician developed to predict the formation of “an ethylene cloud of spherical shape created at an altitude of 141 km [approximately 87.6 miles]” and that was the subject of an “unclassified article.”
One of the documents that The War Zone received via FOIA was a copy of FTD’s official translation of this article, titled “Stochastic Mathematical Model of a Chemiluminescent Artificial Cloud in the Upper Atmosphere,” which was published in a Soviet scientific journal in 1983. The work is attributed to Ye. G. Slekenichs of the Obninsk Branch of the Moscow Engineering Physics Institute.
“A prevalent method of studying the upper atmosphere today involves observing the behavior of artificial luminescent clouds in it,” Slekenichs wrote. “Specifically, observations of artificial chemiluminescent clouds allow determining the concentrations of the minor components of the atmosphere.”
However, the paper notes that creating these clouds is difficult and requires significant preparation, making it valuable to use mathematical modeling to work out various particulars in advance. “This article examines a stochastic mathematical model of a spherical chemiluminescent cloud formed by ejection of a reagent at an altitude of over 120 km [approximately 74.5 miles],” Slekenichs explained.
In addition to describing, theoretically, how one would go about creating this cloud, Slekenichs notably mentions that “this probability algorithm was used to calculate the radiance brightness of a chemiluminescent ethylene cloud, the prototype of which was obtained experimentally.” That sentence includes a footnote that cites another report, dated 1974.
“Unfortunately there is no discussion of any possible purpose for the  experiment,” FTD said of Slekenichs’ paper. It’s also interesting to note that there were reported sightings in Afghanistan of Dome of Light-like phenomena, emanating from what was then the neighboring Soviet Union, as early as 1976.
One of the most compelling theories, of course, remains that the Dome of Light was some kind of countermeasure against American early warning or anti-ballistic missile capabilities, a possible explanation for the phenomenon that was publicly discussed in newspapers and other publications in the late 1980s. It’s certainly very plausible that the cloud could blind or otherwise confuse early warning satellites watching for missile launches or make it hard to spot and track incoming re-entry vehicles for a possible interception – or at least that the Soviets hoped it would be able to do these things.
The RSD-10/SS-20’s range and MIRVed warhead already presented a major challenge for NATO and had prompted the United States to deploy Pershing II medium-range ballistic missiles (MRBM) and BGM-109G Gryphons, a ground-launched derivative of the Tomahawk cruise missile, to Europe in response. Getting rid of the RSD-10/SS-20s was a key objective of the now-defunct Intermediate-Range Nuclear Forces Treaty (INF), which the two countries signed in 1987.
Still, while the INF did lead to the destruction of the RSD-10/SS-20s, save for a small number of them that were decommissioned and put on display, the U.S. military clearly had concerns that the Dome of Light, whatever it was, would become associated with other Soviet ballistic missiles. In 1990, FTD published an engineering memorandum titled “SS-25 DOL Flights.”
The copy of this report that The War Zone obtained via FOIA is heavily redacted, but appears to discuss computer modeling of flights of the road-mobile SS-25 Sickle intercontinental ballistic missile (ICBM), also known as the RT-2PM or RS-12M, as well as by the name Topol, producing a Dome of Light-like effect. “The computer model used [redacted] in this memo has been prepared to generate performance estimates of the SS-25 system for various scenarios,” one unredacted passage reads.
“This phenomenology [the Dome of Light] has been the center of much discussion, and various researchers have attempted to explain it with varying degrees of success,” this document also noted. “By folding in sun and moon angular data, as well as weather data, one should be better prepared to unravel more of the DOL associated mystery.”
We don’t know if FTD or any other element of the U.S. military or Intelligence Community was aware of any actual sightings of a Dome of Light associated with an RT-2PM/RS-12M/SS-25 launch at that time or has been made aware of any such event since then. This ICBM is in increasingly limited service in Russia, but has been publicly used to test new countermeasures against ballistic missile defenses as recently as 2017.
You can find the full copies of the three Dome of Light-related documents we obtained via FOIA here.
These documents, taken together with what had already been known, certainly offers more insight into the Dome of Light, though a conclusive explanation, at least publicly, remains elusive. The 1990 memo also raises interesting questions about whether the Soviets, or subsequently the Russians, continued to experiment with chemiluminescent clouds or other such phenomena after dismantling the RSD-10/SS-20s.
When we at The War Zone initially wrote about this last year, we raised the possibility that, if the concept was indeed a countermeasure against ballistic missile defense systems and was at all viable, that the Russians might be interested in revisiting it in light of new early warning and other missile defense efforts that the United States is pursuing now. The Kremlin has certainly shown a proclivity for exploring other “superweapon”-esque concepts in recent years.
In the meantime, we are continuing to dig into this absolutely fascinating mystery.
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