Somewhere in Argentine Patagonia, in the Lonco Pué Department of Neuquén Province, amid scorched grass and a wind that does not let up for months, stands a white dish thirty-five meters across, pointed at the sky. It listens to space—or perhaps to something else.
To control a spacecraft on the Moon or en route to Mars, one antenna is not enough. The Earth rotates, and any ground station can see a particular patch of sky for roughly a third of the day. For the other sixteen hours, the craft is silent—or talking, but with no one there to listen. That is why every serious space agency builds networks of three stations, spaced roughly 120 degrees apart in longitude: as one slips beyond the horizon, another picks up the signal. NASA has the Deep Space Network—antennas at Goldstone, California; outside Madrid; and in Canberra. The European Space Agency has a similar trio. The logic is always the same: the Earth is round, so geometry is required.
By the middle of the 2010s, China had deep-space communication stations in Kashgar, in the country’s west, and Jiamusi, in the northeast, as well as an antenna in Namibia. The coverage was uneven: a vast hole yawned over South America and the southern Pacific. For missions in low Earth orbit, that is tolerable—a satellite circles the planet in an hour and a half, and a communications window will always turn up. But an interplanetary craft moves slowly relative to the Earth’s rotation, and if it ends up in a zone no station can see, mission control goes blind for hours. Argentina, at roughly 70° west longitude and 38° south latitude, closed that gap almost perfectly.
That is why, in 2014, Buenos Aires and Beijing signed an agreement to build the station. A two-square-kilometer site was leased for half a century—the contract had been drawn up back in 2012, before the official signing of the intergovernmental agreement. Argentina’s Congress approved the project in 2015, and three years later, in 2018, the Espacio Lejano station began operating. For China, it was the missing vertebra in the spine of its deep-space communications network.
What personally fascinates me is how much you can understand about a station’s purpose simply by looking at the frequencies it uses. Espacio Lejano is equipped with transmitting and receiving hardware in three bands: S (2–4 GHz), X (8–12 GHz), and Ka (27–40 GHz). Each is a separate tool, honed for its own kind of task.
The S-band has been the workhorse of space communications since the sixties. Signals in this band pass well through the atmosphere, do not suffer too badly from rain, and make it possible to maintain a stable link with spacecraft hundreds of millions of kilometers away, albeit at low data rates. This is the band normally used for telemetry and control commands—the bare minimum without which a mission is dead.
The X-band offers greater bandwidth. It can pump through images, scientific data, measurement results—all the things the spacecraft is actually flying for. The Chang'e 4 mission, which landed on the far side of the Moon in January 2019, needed relaying through the Queqiao satellite, and ground stations received its data in precisely this band. Without an antenna in the Southern Hemisphere, reception windows would have narrowed—not to zero, but noticeably.
The Ka-band is the highest-frequency of the three, and therefore the fussiest: rain and clouds muffle it, but in Patagonia’s dry climate it works beautifully. This band is used for high-speed data transmission and radiometry—the precise measurement of distances and velocities. Put bluntly, it is also the most interesting from the standpoint of dual use: some military communications satellites and signals-intelligence systems operate in the Ka-band.
This distinction often gets lost in newspaper headlines: a deep-space communications station is not the same thing as a satellite-control station. A satellite in low orbit can be controlled with a small antenna; its signal is powerful, the delay is negligible, the pass is brief. Deep-space communication is different physics: a signal from Mars takes anywhere from four to twenty-four minutes to reach Earth depending on the relative positions of the planets, the power at the antenna input falls to utterly minuscule fractions of a watt, and to pull the signal out of the noise, you need a large dish with cryogenic receivers. A thirty-five-meter antenna is the minimum caliber for serious interplanetary work; NASA has a seventy-meter one at Goldstone.
Formally, the station’s operator is CLTC—China Satellite Launch and Tracking Control General. The name sounds civilian, but the organization’s history begins within the People’s Liberation Army of China. For decades, CLTC ran the ground infrastructure for Chinese space launches, tracked satellites, and maintained communications with crewed Shenzhou spacecraft. When Beijing created the Strategic Support Force in 2015—a service branch bringing together space, cyber, and information operations—CLTC became part of its structure. Then came another reorganization in 2024: the Strategic Support Force was disbanded, and CLTC ended up within the PLA Aerospace Force.
The practical meaning of this whole shuffle is simple: the operator of the Argentine station is a unit of a foreign state’s armed forces. For comparison: NASA is a civilian agency; ESA is an intergovernmental organization; even Russia’s Roscosmos is formally separate from the Ministry of Defense, though the boundaries there are blurred too. China’s space program is structured differently: military and civilian infrastructure are intertwined so tightly that they can be separated only on paper.
The government of Mauricio Macri tried to make that paper as specific as possible in 2016. An additional document was signed, establishing that the station would be used exclusively for peaceful purposes. The document prohibited military use and, according to the Argentine side, granted the right to conduct inspections. But then comes the realm of uncertainty: exactly how can Argentina control what is transmitted and received through the antenna? A radio signal is not cargo in a container; you cannot inspect it at customs. The data are encrypted, the control protocols belong to the operator, and the specialists working at the station are Chinese.
The station’s critics—chiefly in the United States and among Argentine opposition politicians—point to several theoretical scenarios for military use. An antenna operating in the S- and X-bands can track satellites in high orbits, including geostationary ones, where communications satellites and missile-attack early-warning systems sit. In the Ka-band, signal interception is theoretically possible—although a single antenna is not enough for a full-fledged signals-intelligence station; you need a network. Another scenario is using the station to calibrate and guide ballistic missiles or hypersonic vehicles in the Southern Hemisphere, though this seems the least likely option: China does not conduct test launches over South America.
It must be said honestly: none of these scenarios has been confirmed by evidence. None of the public inspections has found military equipment. The problem, though, lies in the very format of those inspections. In 2024, the administration of Javier Milei conducted an inspection of the station that lasted five hours. For a facility with two square kilometers of territory and a complex radio-electronic core, that is a courtesy call, not an audit. Independent experts, including those at American think tanks, note that Argentina has neither the personnel nor the technical means to fully monitor what is happening at the station in real time.
The line between civilian and military space communications is thinner than either side of the argument would like. The same antenna that receives images of lunar soil from Chang'e 4 is physically capable of receiving telemetry from a reconnaissance satellite—the difference lies only in software and the schedule of communications sessions. This is not unique to the Chinese station: NASA’s Deep Space Network antennas are also sometimes used for national-security-related tasks. The difference is in the degree of transparency and institutional safeguards, and those work very differently in Argentina and China than they do in Australia and the United States.
Suppose that in 2015, Argentina’s Congress had said no. What would have happened to China’s lunar and Martian program?
The answer is duller than lovers of geopolitical thrillers might wish. The Chang'e 4 mission would have happened. So would the Tianwen-1 mission to Mars. China had stations in Kashgar, Jiamusi, and Namibia, as well as Yuanwang-class space-tracking ships, which can operate from anywhere in the ocean. Coverage would have been worse: “blind zones” would have emerged, where communications with the spacecraft would be interrupted for several hours. For automated missions, this is unpleasant but not fatal—the onboard computer can operate autonomously. It would have been more critical during landing: if a spacecraft touched down on the Moon at the moment Patagonia was the only station able to see the necessary patch of sky, losing communications in those minutes could cost the mission. But the landing trajectory can be chosen to prevent that—at the price of restrictions on the choice of place and time.
The more serious problem would have been strategic. Without the Argentine station, China would have faced a choice: build additional antennas on its own territory—which does not solve the longitude problem; expand the fleet of Yuanwang ships—expensive and less reliable than a fixed station; or seek another partner in South America. Chile, Brazil, Uruguay—each country has its own political calculations, and none would have offered conditions as comfortable as Argentina under Cristina Fernández de Kirchner, who signed the original agreement. An attempt could have been made to place an antenna in the Pacific—on some island state—but logistics and climate are more difficult there.
In essence, a congressional rejection would not have brought the program crashing down, but it would have forced Beijing to spend several extra years and considerable money rebuilding the network. The timing mattered: Chang'e 4 was flying in 2018–2019, and if an alternative station had not been ready by then, the mission would have had to be either postponed or carried out with degraded coverage. What surprises me is how rarely discussions of this station raise the simple question: why, exactly, did China not build it earlier—and somewhere else?
In 2024, when the Milei team sent inspectors to the station, a revealing scene unfolded: the visit lasted five hours, after which the Argentine side declared that no violations had been found. American diplomats and analysts reacted skeptically. Members of Congress in Washington continued to call the station a threat, while Argentine officials continued to affirm its peaceful status. Both sides were dealing less in facts than in degrees of trust: can an operator that is a unit of a foreign army be trusted on the basis of a five-hour inspection?
The problem goes deeper than one particular antenna. Twenty-first-century space infrastructure lives in a gray zone: the same parabolic dish, the same frequency band, the same operator can serve a scientific mission to Mars on Monday and a communications session with a reconnaissance satellite on Tuesday. These functions can be separated only through institutions: independent monitoring, the permanent presence of inspectors, access to communications-session logs. None of that exists in Lonco Pué—at least, no evidence of it has appeared in the public sphere.
Argentina has found itself in a position familiar to dozens of countries hosting foreign infrastructure: from military bases to undersea cables. Sovereignty is formally preserved—the land is leased, the agreement is signed, inspections are possible. But real control over exactly which photons enter and leave the antenna remains with the operator. This is not a conspiracy—it is architecture. The thirty-five-meter dish in the Patagonian steppe receives signals from hundreds of millions of kilometers away, and for every one of those signals, the host country has neither a decoder nor a key. The question it poses still has no good answer: how do you create transparency in a world where the very object of oversight is an invisible beam between an antenna and a point in space?