A spacecraft that never runs out of fuel sounds like science fiction, but a team at Texas A&M University has taken a small, literal step toward that goal. In experiments conducted at the university’s AggieFab Nanofabrication Facility, physicist Shoufeng Lan and colleagues built micron-scale devices they call “metajets” and showed that a single laser beam can lift and steer them in three dimensions, no onboard propellant required. The results, described in a preprint posted to arXiv and highlighted in an April 2026 Texas A&M engineering news release, represent what the researchers call the first demonstration of three-dimensional maneuvering powered entirely by light.
How a flat surface creates sideways thrust
Conventional solar sails work like mirrors: sunlight bounces off a reflective sheet and pushes the craft forward, almost entirely along the direction the light was already traveling. Steering requires tilting the whole sail, which shrinks the area catching photons and weakens the total force. Decades of solar-sail research have documented these geometric constraints, and they remain a core limitation for any mission that relies on sunlight alone.
Metajets take a fundamentally different approach. Each device is a metasurface, a flat structure patterned at the nanoscale so that incoming light exits at angles dictated by an engineered phase gradient rather than by simple reflection. The concept builds on generalized laws of reflection and refraction that physicists established over a decade ago: by introducing abrupt phase shifts across a surface, designers can bend light in directions that ordinary optics cannot.
In practice, that means a laser aimed straight up at a metajet does not just push it upward. The phase gradient redirects the photons off-axis, and because momentum must be conserved, the device recoils in the opposite direction. The result is simultaneous vertical lift and lateral thrust from a single beam, with no moving parts and no fuel. By tailoring the pattern etched into the surface, the team can tune the ratio of upward and sideways force.
What the experiments actually showed
In the lab, Lan’s group suspended free-standing metajets and illuminated them with a continuous-wave laser, recording trajectories that confirmed controlled motion along multiple axes. A key performance metric from the full manuscript is diffraction efficiency: the initial design redirected roughly 58 percent of incoming light into the desired diffraction order, with the rest lost to specular reflection or absorption. Higher efficiency translates directly into stronger thrust for a given beam power, so that number sets a baseline for future improvements.
The devices themselves are tiny, on the order of microns across, fabricated with the same electron-beam lithography and thin-film deposition tools used in semiconductor research. According to the Texas A&M news release, the team sees this compatibility with existing nanofabrication infrastructure as a practical advantage, though large-scale production has not been attempted.
It is worth noting that the preprint has not yet undergone formal peer review. The underlying physics, momentum transfer from redirected photons, is well established, and the 58 percent efficiency figure is a concrete, reproducible metric. But until independent groups replicate the results and referees scrutinize the methodology, the claims carry the usual caveats of unpublished work.
The gap between a lab demo and a spacecraft
Levitating a micron-scale chip on a benchtop is a long way from steering a probe through deep space. Several major unknowns stand between the current results and any real mission.
Vacuum and microgravity testing. Every experiment so far took place in air, under Earth’s gravity. Air currents, thermal convection, and gravitational settling all complicate radiation-pressure measurements on objects this small. The team has expressed aspirations for microgravity tests, according to the university news release, but no timeline or funding commitment has been disclosed.
Beam-riding stability. Any object propelled by a distant laser must stay aligned with the beam. Published analyses of laser-sail dynamics show that even slight misalignments can grow rapidly, flipping or deflecting a craft off course. Whether the metajet’s phase-gradient design inherently provides self-correcting restoring forces, or whether active beam steering would be needed, remains an open question.
Scaling up. Going from micron-sized test structures to sails measuring centimeters or meters across introduces alignment tolerances and phase errors that are negligible at small scales but potentially crippling at large ones. No public data exist on cost per device, fabrication yield, or the feasibility of stitching many metajet unit cells into a coherent macroscopic array.
Durability. A realistic propulsion system might require continuous or repeated high-intensity laser exposure over weeks or months. Heating, radiation damage, and mechanical stress could degrade the nanoscale patterns that make the whole concept work. The current study does not report lifetime testing.
Where metajets fit in the propellantless-propulsion landscape
The Texas A&M work arrives at a moment of renewed interest in light-driven spacecraft. The Breakthrough Starshot initiative, backed by the late Yuri Milner, has spent years exploring the idea of using a ground-based laser array to accelerate gram-scale probes to a significant fraction of the speed of light, fast enough to reach the nearest star system within a generation. That program envisions conventional reflective sails, and its engineers have grappled with many of the same stability and materials challenges that metajets would face.
What metajets add to the conversation is directional control. A Starshot-style flat sail gets pushed along the beam; steering requires tilting or reshaping the sail. A metajet, by contrast, could in principle generate lateral thrust while remaining face-on to the laser, opening up maneuvering options that flat reflectors cannot easily match. Whether that theoretical advantage survives contact with real-world engineering constraints is the central question the Texas A&M group will need to answer next.
Japan’s IKAROS mission, which successfully deployed a solar sail in 2010, demonstrated that photon pressure can propel a spacecraft in practice, but its maneuvering relied on adjusting the reflectivity of liquid-crystal panels at the sail’s edges, a slow and limited form of steering. Metajets offer a more granular control mechanism, at least on paper.
What to watch for next
The strongest near-term signal will be peer-reviewed publication. If the preprint survives review with its core claims intact, particularly the 58 percent diffraction efficiency and the three-axis trajectory data, the work will carry considerably more weight. Independent replication by another fabrication lab would be an even stronger endorsement.
Beyond that, the milestones to track are vacuum-chamber tests that eliminate air-drag artifacts, microgravity experiments (whether on parabolic flights or the International Space Station), and any formal partnerships with agencies like NASA or commercial space ventures. As of May 2026, none of those steps have been publicly announced.
For now, the Texas A&M metajets represent a genuine and inventive proof of concept: carefully patterned surfaces that convert photon momentum into controllable three-dimensional motion at microscopic scales. The physics is sound, the fabrication is real, and the potential is tantalizing. But the road from a dancing speck of silicon in a university lab to a spacecraft gliding between planets on a beam of light remains, by any honest measure, very long.
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*This article was researched with the help of AI, with human editors creating the final content.
