X-37B: the secret mini-spacecraft returns for key tests

X-37B

The X-37B will take off again in August for its eighth mission, which will include tests of laser communication and GPS-free quantum navigation.

The X-37B, an automated space plane developed by Boeing for the Pentagon, will begin its eighth mission in August 2025. Entrusted to the U.S. Space Force, this unmanned aircraft will this time be used to test two cutting-edge technologies: optical communication via laser in low Earth orbit, and a new quantum inertial sensor capable of navigating without GPS. This type of technical demonstration is part of the US strategy to strengthen the resilience of its space systems in a context of growing competition and risks in orbit. The X-37B remains a central tool for US military orbital experimentation, with more than 3,700 cumulative flight days since 2010.

The X-37B, a secret program with proven technical performance

The X-37B Orbital Test Vehicle program, initially developed by NASA, came under the control of the Department of Defense in 2004. It is a mini-shuttle-type spacecraft measuring approximately 8.8 meters long and weighing 4.5 tons, capable of performing long missions in Earth orbit before returning to land autonomously on a runway, like an airplane.

Launched for the first time in 2010, the X-37B has completed seven missions for a cumulative total of more than 3,774 days in orbit, or more than ten years. Its last mission, OTV-7, ended in March 2025 after 434 days in flight, demonstrating its exceptional endurance. During this last flight, one of the major technical objectives was to demonstrate orbital airbraking capabilities, a technique that allows altitude or trajectory to be changed using the atmosphere without excessive fuel consumption.

The U.S. Space Force, which operates the program through the 5th Space Operations Squadron, uses the X-37B to test strategic technologies, many of which are classified. Although not an operational system, this aircraft plays a key role in evaluating future orbital architectures, with a growing focus on the militarization of space capabilities.

Laser communication: towards more secure data transfer in orbit

The main new feature of this eighth mission is an experiment in laser communication between satellites. The aim is to demonstrate the X-37B’s ability to exchange data via infrared light beams with a network of satellites in low Earth orbit (LEO), at an altitude of approximately 2,000 kilometers.

Unlike conventional radio transmissions, laser communications enable much higher data rates (several gigabits per second) and are less vulnerable to interception or jamming. This technology is already being studied by operators such as SpaceX (Starlink) and Airbus (OneSat), but its integration into a military framework is a challenge in terms of securing critical data flows.

By using multipoint relay networks—known as proliferated relay networks—the Space Force aims to strengthen the resilience of US orbital systems by avoiding dependence on a single point of communication. This responds to scenarios where an enemy could target a single strategic satellite to disrupt an entire system. By increasing the number of relays and opting for optical transmissions, network integrity is preserved even in the event of a technological attack.

This approach is part of the Pentagon‘s strategy of distributed orbital architectures, which are less vulnerable to anti-satellite strikes (ASAT) and better suited to operations in contested environments, particularly against powers such as China and Russia.

X-37B

Quantum navigation: testing inertia without GPS in an orbital environment

The second innovation being tested is a quantum inertial sensor. This is a device capable of measuring movement with extreme precision by relying on the behavior of cold atoms subjected to magnetic fields. This type of sensor, still in the demonstration phase in most cases, could eventually replace or supplement GPS systems.

This development is of strategic importance. In situations where access to GPS signals is denied, whether through jamming or destruction of the corresponding satellites, an autonomous on-board navigation system becomes critical for the maneuvering autonomy of satellites and orbital platforms.

According to the Space Force, the sensor on board the X-37B is the most powerful ever tested in space. Its sensitivity would allow it to maintain a precise orbital position for long periods of time, even without external assistance. This would apply in particular to missions in cislunar space, a strategic zone between Earth and the Moon that is targeted by the major powers for their future orbital bases and missions to Mars.

There is also a military stake: a satellite capable of navigating without relying on external signals is more difficult to detect and intercept, and can continue its mission even in a jammed or hostile environment. This advance heralds a generation of autonomous space vehicles with expanded capabilities.

A tool for strategic influence in the orbital geopolitical context

The activation of the X-37B for a new mission comes at a tense time: tensions in outer space are growing. For several years, the United States, Russia, China, and India have been developing space military capabilities, including anti-satellite weapons, inspector satellites, and dual-use platforms.

The launch from the Kennedy Space Center is both a technological and political act. It shows that the United States is continuing to develop disruptive technologies to maintain its strategic advantage in space. General Chance Saltzman, head of US space operations, emphasized that this mission was intended to make the US joint force “more connected, more resilient, and ready to act against any threat.”

The X-37B is also a deterrent: its partially classified capabilities, long mission durations, orbital mobility, and technological testing make it an unpredictable tool that complicates adversarial planning.

Finally, these missions reinforce the influence of US manufacturers in the military space sector. Boeing, a long-standing partner, is strengthening its position in the autonomous orbital vehicle segment. But beyond that, the entire space defense industrial chain benefits from these campaigns: suppliers of optics, quantum sensors, ground stations, and onboard processing software.

A technical milestone toward US orbital autonomy

This eighth flight of the X-37B represents an important step towards autonomous, modular and resilient space capabilities. Through experiments in laser communications and GPS-free navigation, the Space Force is validating essential technological building blocks for the military orbital architecture of the 2030s.

As the militarization of space progresses rapidly, the United States is seeking to secure its access, maneuverability, and communication capabilities in all conditions. If conclusive, the results of this mission could redefine the standards for future reconnaissance, command, and deterrence satellites.

The logic is clear: in an orbital space that has become contested, congested, and strategic, technological autonomy is becoming the foundation of the survivability of US platforms.

War Wings Daily is an independant magazine.