“The OTV-8 demonstration of laser communications will be a significant milestone in the U.S. Space Force’s ability to leverage proliferated space networks as part of a diversified and redundant space architectures,” said Chief of Space Operations Gen. Chance Saltzman. America’s Space Force is preparing to send its enigmatic X-37B spaceplane aloft on August 21, and the mission’s technical goals are nothing short of outrageous: the flight testing of a quantum inertial sensor and a laser communications system that would revolutionize the ruggedness and autonomy of future space vehicles. The X-37B, or the Orbital Test Vehicle, is blasting off on its eighth trip to space aboard a SpaceX Falcon 9 rocket from Kennedy Space Center.
The launch comes just a 5.5-month span after its previous 434-day mission ended, demonstrating the rapid-rate turnaround and operating capability of the platform. While much of the information is still classified, Space Force authorities stated that OTV-8 will be carrying two payloads that promise to set new records for data transfer and navigation in space. The highlight of the mission is a laser communications demonstration that will link up with “proliferated commercial satellite networks in low Earth orbit (LEO),” terminology that unambiguously applies to SpaceX’s Starlink constellation, which now has over 8,000 operational satellites in LEO.
The advantages of laser communications over radio frequencies are deep: higher throughput, reduced power, reduced terminal size, and enhanced security. The infrared lasers have a narrow beam, which makes them inherently more difficult to intercept or jam and offers a high degree of protection against eavesdropping and signal interference. But the technical hurdles are enormous. The LEO satellites travel at approximately 17,000 miles per hour, and there has to be split-second coordination to create and sustain laser links. Even minute mechanical vibrations or environmental fluctuations will ruin the connection, so high-reliability performance is a daunting engineering challenge. The X-37B demonstration is intended to demonstrate that such connections can be established in the real-world operating environments with commercial constellations’ assistance to create a redundant, fault-tolerant mesh for military communications. The second payload consists of a quantum inertial sensor, the most capable device of its kind ever deployed to space. Classical inertial measuring devices make use of mechanical gyroscopes and accelerometers, whereas quantum sensors use the wave properties of ultracold atoms.
By sensing interference patterns of rotated and accelerated atoms, these devices are able to determine orientation and position with unworldly precision—completely independent of external signals like GPS. This is done through atom interferometry, in which atoms are cooled and manipulated with lasers, split and recombined, and employed to sense phase shifts induced by motion. Measurements created in this manner are immune to electromagnetic spoofing and jamming, a challenge growing increasingly serious as an adversary acquires more sophisticated electronic warfare capabilities. Col. Ramsey Horn, commander of Space Delta 9, highlighted the operational importance: OTV 8’s quantum inertial sensor demonstration is a welcome step forward for operational resilience in space. “Whether navigating beyond Earth based orbits in cislunar space or operating in GPS-denied environments, quantum inertial sensing allows for robust navigation capabilities when GPS navigation is not possible. Ultimately, this technology contributes significantly to our thrust within the Fifth Space Operations Squadron and across the Space Force guaranteeing movement and maneuverability even in GPS-denied environments.” Finally, this technology is crucial for our role in the Fifth Space Operations Squadron and across the Space Force providing transit and maneuverability even in GPS-denied spaces. Building such a sensor for space flight is not an easy job.
Atom interferometers are very sensitive to outside perturbations, like temperature changes, vibrations, and errant magnetic fields.
New miniaturization and vacuum chamber manufacturing developments on the materials titanium and ceramic, and additive manufacturing, enable compact, extremely durable space flight deployable instruments to be produced. The sensors are now able to withstand ultrahigh vacuum and stable laser conditions for months or years, a prerequisite for operational success in orbit. The implications of these tests extend well beyond the X-37B. As space continues to become increasingly crowded and contested, the ability to operate on missions regardless of brittle satellite constellations, and to communicate over distance securely, will be essential. The OTV-8 mission ventures into a future where, through the use of advanced quantum and photonic technology, spacecraft will be, by design, not only more autonomous, but more survivable than dangers constituting the more complex space environment.
