ROT54 or the Herouni Mirror Radio Telescope

The ROT54 radio-optical telescope is located in Orgov village, Aragatsotn Province of Armenia, at an elevation of 1,700 meters. It was designed by the Armenian physicist and engineer Paris Herouni, who spent 17 years navigating Soviet bureaucracy to bring his vision to life. Despite strong pressure to build the project in Crimea rather than in Armenia, Herouni secured approval to construct the observatory in Armenia—an achievement that reflects his persistence and deep devotion to his homeland.

Herouni Mirror Radio Telescope (Зеркальный радиотелескоп геруни) Patent No. 1377941 Image credits: База патентов СССР (USSR Patent Database)

Herouni was known for his innovative approach to radio engineering and his dedication to advancing scientific knowledge in Armenia. Over his career, he published around 353 scientific works, including 248 papers, four monographs, and 25 patents. He was also a passionate science communicator, frequently appearing in newspapers, magazines, radio, and television, with media coverage about him spanning the USSR, Russia, Armenia, USA, France, and Italy.

ROT-54 in winter

Herouni carried out several expeditions along the southern slopes of Mount Aragats before selecting this site as the future location for the telescope. The natural, crater-like shape of the landscape was ideal for installing the dish, while the 13th-century Tegher Monastery and the biblical Mount Ararat formed a dramatic backdrop. At the time, there were plans to relocate the village—a common practice during the Soviet industrialization era. Rather than investing in roads, gas supply, or other essential infrastructure for remote mountain communities, Soviet authorities often chose to resettle villagers in nearby towns. By launching the ROT54 project, Herouni built a road from scratch, connected the village, and ultimately saved Orgov from being erased.

Inside the control room of ROT-54

While Paris Herouni patented many inventions, this project became his Mona Lisa—the first Radio-Optical Telescope (ROT-54/2.6). The structure is a massive antenna with a diameter of 54 meters (177 ft), boasting some of the finest technical parameters among large antennas worldwide.

Aerial photo of ROT-54 telescope

Constructed between 1975 and 1985, the telescope was active from 1986 to 1990 before ceasing operations around 1990. In the mid-1990s, there was a proposal for the restoration of the telescope. Between 1995 and 2010, it underwent modernization with new control computers and feeds, and observations resumed in collaboration with the Astronomical Society of Russia and the National Technical University of Athens.

Me sitting in the control room of ROT-54

However, in 2012, the operations ceased again when a control arm failed, immobilizing the secondary mirror. The Armenian state couldn't cover the cost of repairs, leading to the mothballing of the research complex. Future operation requires further upgrades to the control systems, comprehensive adjustments, replacement of outdated analog sensors with digital ones, and modernization of the data processing systems. According to experts, these upgrades will cost approximately $25 million.

A historical photo shows the newly installed telescope with a helicopter hovering above it. The small trees planted at the time have since grown taller than the surrounding buildings, turning the site into a surprisingly pleasant and shady place during the hot summer months.

The ROT-54/2.6 radio-optical telescope enabled a wide range of advanced radio astronomy observations, including:

• Studies of ultra-distant objects such as quasars and radio galaxies

• Observations of pulsars, supernovae, and their temporal changes

• Investigation of radio sources with angular sizes smaller than 1 arcsecond

• Analysis of fine inhomogeneities with angular sizes below 1 arcsecond

• Study of thermal radiation from newly formed stars

• Research on nebulae and T Tauri stars

• Organization of simultaneous radio and optical observations of well-known celestial objects, allowing results from leading radio observatories to be combined into a new unified catalog

• Searches for new molecules in comets and planetary atmospheres within the Solar System
  

Thanks to its exceptionally low intrinsic noise temperature of approximately 5 K, the telescope’s radio noise level did not exceed 1–2 mJy. With a receiver bandwidth of 1 GHz and an integration time of just 1 second, ROT-54/2.6 was capable of detecting extremely faint objects. Its sensitivity was comparable to that of major facilities such as the Very Large Array (VLA) in New Mexico, despite the VLA consisting of 27 antennas.

"Arev" solar power station

Another giant “dish” comes into view as soon as you enter the site. Many visitors mistakenly assume it’s a telescope, but it’s actually a solar power station—another remarkable invention by Paris Herouni.

“Arev” is an unfinished solar thermal power station designed by Paris Herouni

In the 1990s, during Armenia’s energy crisis—when the country’s nuclear power plant was offline, the war in Artsakh was ongoing, and the nation faced a blockade—Paris Herouni set out to develop efficient solar energy systems. In 1991, he presented his “Arev” thermal power plant project, protected by seven international and two Armenian patents, demonstrating higher efficiency than comparable international projects. The project attracted attention from major international organizations and investors, particularly from the United Kingdom, and construction began. However, when the project was nearing completion, the investors attempted to claim Herouni’s patents. The matter went to court, construction was delayed, and the project was never resumed.

An aerial view of Herouni Mirror Radio Telescope

Today, this place attracts tourists from around the world. For urban explorers visiting Armenia, this place is a must-visit!

The "Orbita" Antenna

I am standing near the giant "Orbita" antenna and pointing towards west

Within the territory of the Herouni United Space Center, visitors can also see a massive antenna known as “Orbita.” The Orbita (Орбита) system was the world’s first national satellite television network, launched by the Soviet Union in 1967. Because the USSR covered an enormous territory, laying cables to every remote region was impractical. Instead, a network of ground stations equipped with large, iconic parabolic antennas was built to receive signals from Molniya satellites. Armenia was also part of this network and had several Orbita antennas. At least three are known to me, with two surviving to this day. According to available information, the Orbita station in Armenia became operational in November 1977, though it is unclear whether this date refers to this specific station or another antenna; further verification is required.

The launch of this station coincided with the construction of the 311.7-meter Yerevan TV Tower, which allowed Armenia to receive the Second Program of Central Television from Moscow via the Molniya and Raduga satellite constellations. More on this you can read in the following article...

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