A spacecraft that could reach the nearest star system in about 20 years would need to travel at a meaningful fraction of the speed of light. No existing technology comes close. But a team at Texas A&M University, led by physicist Shoufeng Lan, believes a new class of laser-driven nanostructures they call “metajets” could eventually make that kind of speed possible, and they have published the first experimental evidence that the underlying physics works.
Their results, published in the Elsevier journal Newton in early 2025 and available as an open-access corrected proof, describe engineered surfaces that do something no conventional lightsail can: generate both thrust and lift simultaneously from a single laser beam. That dual-force capability could give a spacecraft full three-dimensional maneuverability, allowing it to accelerate, steer, and correct its course without mechanical actuators or onboard fuel.
The concept arrives at a moment when multiple research groups and agencies are investing in alternatives to chemical rockets for deep-space propulsion. NASA continues to fund diffractive lightsail research, and the privately backed Breakthrough Starshot initiative has spent nearly a decade exploring whether gram-scale probes pushed by ground-based lasers could reach Alpha Centauri within a generation. Metajets offer a distinct twist on that vision: rather than relying on a simple reflective membrane, they treat the sail itself as a sophisticated optical device.
How metajets generate force in three dimensions
The physics starts with a principle familiar to anyone who has held a garden hose and felt it push back: momentum transfer. When a laser beam strikes a surface, photons carry momentum, and the surface absorbs a tiny kick. A flat mirror bounces light straight back and gets pushed straight forward. A metajet surface, by contrast, is patterned at the nanoscale so that it bends transmitted and reflected light at carefully chosen angles. Conservation of momentum means the surface receives a reaction force that points in a different direction than the incoming beam.
By engineering those angles precisely, Lan’s team showed they could produce forces both along the beam axis (propulsion) and perpendicular to it (lift or lateral steering) from a single illumination source. The results, detailed in both the Newton paper and a companion preprint on arXiv, matched numerical simulations closely, suggesting the theoretical framework is reliable.
A critical detail in the preprint is the scaling argument: because the force scales with surface area, a larger sail would generate proportionally greater directional thrust without added complexity in the control system. In principle, a single continuous laser beam could both accelerate and steer a craft, with course corrections achieved by adjusting the beam’s angle or intensity profile rather than physically tilting the sail.
The 20-year timeline and what it assumes
The projection that a metajet-equipped sail could reach Alpha Centauri, roughly 4.37 light-years away, in approximately 20 years comes from the research team itself, as reported in a Texas A&M release republished by Phys.org. For perspective, NASA’s Voyager 1, the fastest human-made object to leave the solar system, would need roughly 73,000 years to cover the same distance at its current speed of about 17 kilometers per second. A 20-year transit implies sustained travel at around 20 percent of the speed of light.
That figure is an aspirational benchmark, not an engineering specification. It depends on assumptions about laser power, sail mass, and sustained acceleration that the published papers do not fully detail in operational terms. The implied laser array would need to deliver continuous, multi-gigawatt power over astronomical distances while maintaining beam quality and pointing accuracy on a target only meters across. These are the same scaling challenges that have kept Breakthrough Starshot in the conceptual phase for years, and no group has yet demonstrated hardware that meets them.
Readers should treat the 20-year number as a statement about what the physics permits under optimistic conditions, not as a mission timeline. It captures the order of magnitude of what might be achievable if metajet sails, high-power laser arrays, precision pointing systems, and robust spacecraft integration all perform near their theoretical limits.
Gaps between the lab bench and deep space
Several substantial unknowns separate the Texas A&M demonstrations from anything resembling flight-ready hardware.
The experiments were conducted under controlled laboratory conditions, not in the vacuum and thermal extremes of space. The metasurfaces were fabricated on substrates and tested over limited time intervals using laser powers compatible with tabletop optics. Whether the nanoscale patterns would survive the intense radiation flux required for interstellar acceleration, or whether they would degrade in ways that destroy the carefully tuned force profiles, has not been tested.
Beam-riding stability is another open question. When an ultrathin sail drifts off the center of a laser beam, radiation pressure can amplify the displacement, causing the sail to tumble or fly out of the beam entirely. A 2024 study in Nature Communications showed that nanophotonic metagrating membranes can exhibit dynamically stable propulsion under intense laser pressure, with optical forces that tend to restore the membrane toward the beam center. A subsequent preprint reported that engineered grating dispersion can enhance that stability by orders of magnitude. Whether metajets inherit or improve upon these restoring properties has not been investigated. The two lines of research share the idea of using patterned surfaces as control elements, but they have not been combined in a single experiment or design study.
Manufacturing presents its own hurdles. The metasurfaces demonstrated so far are tiny. Scaling them to the square-meter dimensions needed for a functional sail, integrating them with a payload and support frame without disrupting the optical response, and managing the heat generated when a sail continuously absorbs and redirects high-power laser light are all unsolved problems. The Newton paper and its companion preprint focus on demonstrating the basic force mechanism, not on materials durability, deployment, or system-level trade-offs. Those omissions are standard for early-stage photonics research, but they should temper expectations about near-term applications.
No public statement from NASA links the metajet concept to any funded program. NASA’s diffractive lightsail research page confirms that directing transmitted and reflected light can generate propulsion and navigation forces, but the agency’s documentation emphasizes fundamental challenges and research milestones still ahead, not endorsement of any single approach. The metajet work fits within this broader research direction without yet being part of it institutionally.
Where metajets fit in the propulsion landscape
The strongest contribution of the metajet research is conceptual: it shows that laser-driven sails need not be passive mirrors. They can function as active optical components that sculpt the momentum of light to produce tailored force vectors in three dimensions. That is a meaningful step beyond earlier lightsail models, which generally assumed simple reflection and left steering to mechanical tilts or auxiliary thrusters.
The peer-reviewed Newton publication and the arXiv preprint both report original experimental data with named authors, detailed device geometries, and reproducible methods. The theoretical framework they present, momentum transfer at engineered interfaces, is well established in photonics. What is new is the application to propulsion and the demonstration that simultaneous thrust and lift can be extracted from a single beam. Within that scope, the claims are modest and well supported: measured forces matched numerical predictions.
Independent work on beam-riding stability and NASA’s ongoing diffractive sail research confirm that the broader field of metasurface-based lightsails is active and producing quantified results. Multiple groups now see promise in replacing simple reflective films with more sophisticated optical architectures. The metajet concept adds a specific, experimentally validated mechanism to that toolkit.
Whether this advance will ultimately translate into practical interstellar probes depends on progress far beyond the laboratory, from multi-gigawatt laser infrastructure to nanoscale manufacturing at sail-sized scales. But the physics underpinning the idea appears sound, the early demonstrations are credible, and the work opens a line of inquiry that the field had not previously explored in this form. For now, metajets represent a proof of concept worth watching, not a mission plan, but a reason to take the next set of questions seriously.
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*This article was researched with the help of AI, with human editors creating the final content.
