How do missile early-warning systems work, and can Europe replace the U.S. for Ukraine?

On the night of October 12, Russia launched a ballistic missile strike on Kyiv, and the following evening it attacked the capital again, targeting residential areas in particular. According to Ukrainian President Volodymyr Zelenskyy, Ukraine did not receive advance warning from its partners about the missile threat. This occurred amid a deterioration in relations between Kyiv and Washington over U.S. President Donald Trump’s demands that Ukraine cease its strikes on Russian oil refineries.

According to The Kyiv Independent, during talks with Ukrainian representatives, the U.S. side allegedly threatened to restrict the exchange of intelligence if Kyiv did not stop its attacks on Russian energy infrastructure. At the same time, Ukrainian Foreign Minister Andriy Sibiga stated that intelligence cooperation with the U.S. is continuing, and Trump himself publicly denied that the transfer of information had been halted. 

Therefore, it is currently unknown whether the lack of warning was due to technical issues, a delay in data transmission, or other reasons. Early warning of missile strikes depends on the operation of satellites, ground-based radars, data processing systems, and communication channels. Detecting a launch is not the same as quickly determining the missile’s trajectory and relaying the information to the country under threat. 

UA.News explains how these systems work, which companies are behind their development, and whether Europe will be able to create an alternative source of information for Ukraine.

How the early warning system works

Early warning of a missile attack relies not on a single satellite or radar, but on a complex of interconnected technologies. It must detect the launch, confirm the presence of a threat, determine the missile’s trajectory, and transmit the information to those responsible for the response.

The first level consists of space-based infrared sensors. When a missile engine is operating, it emits a significant amount of heat, creating a distinctive signal that can be detected from orbit. Specialized satellites monitor large areas of the Earth and search for such signals against the backdrop of other sources of infrared radiation.

Detecting a thermal signal does not immediately mean that the system knows the exact target of the missile. First, it is necessary to distinguish a possible launch from other phenomena, process the data, and assess how reliable the information is.

The second level involves radar surveillance. Ground-based radars emit radio waves and analyze the reflected signals to determine an object’s position, speed, and direction of travel. Successive measurements make it possible to refine the trajectory and predict the likely impact area.

The third level consists of data processing and transmission centers. These centers consolidate information from various sensors, assess the threat, and transmit alerts to the military. For international cooperation, it is not only technical capabilities that are important, but also secure communication channels, system interoperability, and rules for accessing intelligence data.

These stages can occur simultaneously. Satellites detect the launch, radars refine the trajectory, and software systems update the threat assessment. However, detecting a launch, calculating the impact site, and transmitting a warning to another country are distinct tasks.

Why a warning might come too late

The time available to respond depends on the type of missile, flight range, launch site, trajectory, and sensor availability. Ballistic missiles can cover a significant portion of their path in a very short time, so even a fully functional system cannot provide an unlimited amount of time.

A satellite may detect the engine’s thermal signature before a ground-based radar receives enough data to reliably track the target. At the same time, satellite sensors have their own limitations: their sensitivity, observation geometry, the frequency of coverage of a specific area, and the speed of data processing all play a role.

Weather can also affect individual sensors and the overall quality of observation, although capabilities depend on the specific technology. Infrared satellites, radars, and optical systems operate on different principles, so it cannot be said that any cloud cover automatically makes it impossible to detect a launch.

After the first attack on Kyiv, adverse weather conditions were cited as one of the possible explanations for the lack of warning. However, this explanation does not resolve questions regarding the timeliness of information sharing. To determine the causes of the delay, it is necessary to know exactly when the sensors detected the launch, when the warning was generated, and whether it was transmitted to the Ukrainian military in time.

SBIRS Satellites and Next-Generation Systems

The U.S. SBIRS system—Space-Based Infrared System—was developed to detect missile launches, assess threats, and support missile defense. It combines satellites in geostationary orbit, infrared sensors in highly elliptical orbits, previous generations of Defense Support Program satellites, and ground-based infrastructure. 

Geostationary satellites are located at an altitude of approximately 35,786 km above the equator and remain over roughly the same area of the planet. This allows for long-term observation of large regions. Satellites in highly elliptical orbits complement this picture by providing observations of areas that require a different orbital geometry.

The system uses infrared sensors to detect thermal launch signatures. The data collected is transmitted to Earth, where it is processed and cross-referenced with other observations. A key advantage for the U.S. lies not only in its satellites but also in its decades of experience integrating space-based sensors, ground systems, command centers, and military communication channels.

One of the main industrial partners is Lockheed Martin, which developed the SBIRS GEO geostationary satellites. Northrop Grumman is involved in the development of satellite technologies and ground infrastructure. Other defense contractors are also involved in the development of data processing systems.

The U.S. is already developing the next generation—Next Generation Overhead Persistent Infrared, or Next-Gen OPIR. It is intended to enhance the capabilities for detecting and tracking complex missile threats. The program includes new geostationary satellites from Lockheed Martin and polar-orbiting satellites being developed by Northrop Grumman.

At the same time, the U.S. is expanding the Tracking Layer—a satellite component in lower orbits designed to track missiles in greater detail. The idea is to combine observations from different orbits, increase the number of available measurements, and make the system more resilient to the loss of individual components.

Ground-based software also plays an important role. In particular, the FORGE system is designed to process data from satellites of different generations using a modular architecture that can be upgraded without completely replacing the system. U.S. defense companies, including SciTec and BAE Systems, are working on its development.

Thus, the U.S. advantage lies in global coverage and the integration of many components into a single infrastructure. It does not merely detect thermal signals but helps form an operational picture of the missile threat.

Europe has powerful radars, but its satellite system is still under development

European countries possess significant capabilities in radar surveillance and missile defense. For example, the British RAF Fylingdales station uses a powerful early-warning radar capable of detecting and tracking ballistic targets at long ranges.

The French company Thales is developing the Ground Fire radar for integrated air and missile defense. It features an active phased-array antenna and is designed, in particular, to detect ballistic threats. The system is part of the European SAMP/T NG program, which is being developed by France and Italy. 

The German company HENSOLDT manufactures the TRML-4D radar, designed to detect and track air targets. It can operate within air defense systems, but it should not be equated with a global satellite early-warning system: it is a different class of equipment with a different purpose. 

Europe’s problem lies not in a lack of technological expertise, but in the fact that national radars, satellites, and control centers do not yet form a fully autonomous pan-European space-based missile launch detection system comparable to the American one.

Satellite-based early warning requires specialized infrared sensors, continuous surveillance, secure communication channels, and ground-based processing infrastructure. European countries have conducted technology demonstrations and developed individual components, but this does not yet mean they have a fully-fledged system capable of providing operational warnings around the clock.

JEWEL and Odin’s Eye: Plans for a European System

One of the key projects is JEWEL—Joint Early Warning for a European Lookout. France and Germany are developing it as the foundation for creating a European capability to detect missile launches from space and transmit data in real time.

The project involves developing its own satellite component and integrating it with ground-based radars and control centers. Its goal is to reduce Europe’s dependence on U.S. systems and strengthen European countries’ early warning capabilities.

JEWEL is linked to the Odin’s Eye research initiative, which is coordinated by the German company OHB System. Companies and research organizations from several countries participated in developing the project’s technological foundation, including Airbus Defence and Space, ArianeGroup, Diehl Defence, HENSOLDT, Leonardo, GMV, and Fraunhofer-Gesellschaft.

The European program is expected to gradually achieve initial operational capability in the early 2030s.

Technically, Europe aims to build a system based on the same general principle as the U.S.: satellites detect a launch, radars refine the trajectory, and control centers consolidate the data and issue warnings. However, the final specifications of the future constellation and its capabilities cannot yet be compared to the already deployed U.S. infrastructure.

How the U.S. and European systems differ

The main difference lies in the maturity and scale of the infrastructure. The U.S. has a fully deployed global space surveillance system, ground-based processing centers, and well-established military procedures. European countries have strong radar and industrial capabilities, but their own satellite-based early warning component is still under development.

The U.S. system is gradually transitioning from SBIRS to Next-Gen OPIR and new satellite constellations. Europe, on the other hand, must create a common framework that integrates national capabilities and new space-based sensors. This requires not only technology but also agreements on funding, governance, standards, and access to classified data.

At the same time, satellites do not replace radars, and radars do not replace satellites. The space component can detect a launch at an early stage, radar systems refine the trajectory, and command systems integrate the information. Without rapid data transmission, even the best sensor cannot provide a complete warning cycle.

Europe’s lag in this area is primarily due to the lack of a fully deployed, autonomous space component. The continent has the industrial resources to build its own system, but its development, the launch of satellites, and integration with national structures will take time. In the short term, Europe will not be able to fully replace the U.S. infrastructure.

Why Suspicions Arose Regarding the U.S.

The lack of advance warning about the October missile strikes on Kyiv has become a politically sensitive issue amid new disagreements between the Donald Trump administration and Ukrainian leadership. The issue escalated following reports of possible threats from Washington to restrict the exchange of intelligence due to Ukrainian attacks on Russian oil refineries.

On October 13, Volodymyr Zelenskyy stated that Ukraine had not received advance warning from its partners about the Russian ballistic missile strike on Kyiv, during which five missiles struck civilian infrastructure. The president emphasized that information about ballistic missile launches is critical for saving lives. 

He also noted that following the energy ceasefire announced by Trump, Ukraine refrained from striking Russian oil refineries, while Russia continued to attack Ukrainian energy and critical infrastructure. 

The day before, according to Euronews, during talks between the Ukrainian delegation and U.S. representatives in Florida on October 9, Trump’s special envoys Steve Witkoff and Jared Kushner allegedly warned of a possible suspension of intelligence sharing and U.S. arms purchases under the PURL program if Kyiv did not stop strikes on Russian oil refineries. 

On October 13, Trump publicly denied that the exchange of intelligence with Ukraine had been suspended. Responding to reporters’ questions about whether the U.S. had stopped sharing such information, he said, “No, we didn’t do that,” adding that Washington continues to assist Ukraine and is working to end the war. On the same day, Ukrainian Foreign Minister Andriy Sibiga stated that the exchange of intelligence with the U.S. is continuing. 

However, the denial of a complete halt to intelligence sharing does not in itself explain why Ukraine did not receive a warning about a specific missile strike. General intelligence sharing can continue even if certain data did not arrive on time or was not transmitted in a specific instance. There is currently no public evidence that Washington deliberately withheld information about the missile launch targeting Kyiv.

To clarify the circumstances, we must distinguish between at least three scenarios: U.S. or other partner systems failed to detect the launch in time; the data was received but could not be processed or transmitted in time; or the information was available, but a decision was made not to share it with Ukraine. The latter scenario would imply a political or operational decision, but it can only be confirmed if there is relevant evidence.

In March 2025, the Trump administration had already temporarily suspended part of the intelligence-sharing with Ukraine during a diplomatic row, though cooperation was later resumed. It is precisely this precedent that explains why the new reports are causing concern in Kyiv. A UA.News article on the risk of leaving Ukraine without intelligence data examines in greater detail Ukraine’s dependence on U.S. capabilities and the consequences of a potential restriction on such cooperation.

Thus, while the political context raises questions about the reliability of intelligence sharing, it does not allow us to automatically link the lack of advance warning to a decision by the White House. To determine the cause, data is needed on the detection of missile launches, the time it took to process the information, and its transmission to the Ukrainian side. These details generally remain classified.

Can Europe Replace the U.S. for Ukraine?

In the short term—absolutely not. European countries can provide Ukraine with information from their radars, intelligence assets, and other sources. However, this is not the same as having its own global space-based missile launch detection system.

JEWEL is intended to serve as the foundation for European autonomy, but before it can become operational, a satellite component must be developed, integrated with ground-based sensors, and data transmission established. Even after the first satellites are launched, it will take time to test the entire system and establish a fully functional network.

Until then, Europe can strengthen its existing capabilities: modernize radars, improve information sharing between countries, and establish backup warning channels. This will not replace the U.S. system, but it can make the overall architecture more resilient.

For Ukraine, it is important not only who detects the launch but also how quickly the information reaches the Ukrainian military. Even the best sensor will be of no use if the warning is delayed during processing or transmission.

The October attacks demonstrated just how crucial the reliability of international data exchange is. At the same time, without access to technical information about how partner systems operate, it is premature to draw definitive conclusions about the reasons for the lack of warnings. 

The strategic objective for Ukraine and its partners is to ensure that sensors, command centers, and communication channels interact in such a way that information about a missile threat is received as early as possible.