As companies continue to innovate, Ukraine's unjammable fiber-optic drones are flying farther and farther, but one company is questioning whether it's worth continuing to extend their range.

These drones, which can transmit commands and video through a physical cable, are not affected by enemy electronic warfare, specifically conventional radio-frequency jamming. Providing clearer video feeds than other FPV drones, they're useful for both surveillance and attack, and Ukrainian officials and companies have celebrated as their ranges have increased.

But TechEx, a major Ukrainian fiber-optic and interceptor-drone maker, told Business Insider that pushing those limits further may not be worth the trade-offs. The company has built models with ranges of up to 35 and 40 kilometers.

"We are currently considering whether it's still necessary to do the next versions of the fiber optic drones to fly, let's say, 45 or 50 kilometers," said Oleg, a TechEx executive who asked to be identified only by his first name for security reasons.

The reason behind the hesitation is that flying farther requires a heavier spool, as well as larger batteries to keep the added spool weight aloft, Oleg said. "This may affect the amount of the payloads carried by the drone."

"So we are still figuring out whether it's something that will be actually used on the front lines to do that long-range FPVs, or we will stick to, let's say, 40 or 45 kilometers."

Drone companies are constantly having to balance the weight of the cameras, explosives, weaponry attachments, communications gear, and other equipment. That balance is harder for fiber-optic drone makers to maintain because their drones are also carrying a spool of cable.

Some Ukrainian drone makers have also said that shorter ranges are more effective anyway for fiber-optic drones because longer distances increase the risk of the cable breaking.

Describing TechEx's Stalker XO-10 and Stalker XO-15 drones, Ukraine's state-backed innovation platform Brave1 said the "fiber-optic drones have some limitations, including the need to carry a coil of cable that gradually unwinds during flight and provides communication with the operator." "Since the coil itself has some weight, this can limit the payload of the UAV," it said, referring to uncrewed aerial vehicles. Brave1 said that TechEx has so far been able to "mitigate this limitation" of the cable weight "through good engineering solutions" and assessed its work "allows these drones to achieve high payloads while maintaining the other advantages of fiber optics." Whether that would continue to be true at longer ranges is a question mark right now.

Olha, a TechEx representative, told Business Insider that the company developed technology to make the spool lighter, making "tiny tweaks and changes" to how it's made and how the fiber is wound onto it. Ukraine's Ministry of Defense said last year that the Stalker series drones have a "record-low spool weight among Ukrainian fiber-optic drones."

Not all companies see the weight-to-range payoff the same way, and that could be good for Ukraine. Units use a host of drones from different companies for different missions, and soldiers say they like the flexibility to choose the equipment best suited to each mission. Some missions may call for longer-range drones carrying smaller payloads, while others require more firepower over shorter distances. And attack missions aren't the only ones where explosive weight is a factor. Soldiers have described using fiber-optic drones for intelligence gathering with their onboard cameras. But there can still be a trade-off, with some higher-quality cameras weighing more.

Fiber-optic drones are just one part of Ukraine's growing arsenal, which includes long-range strike drones, mid-strike drones, and even heavy bombers.

Many of these are able to carry much heavier payloads than small FPV drones. Each system comes with advantages and vulnerabilities, forcing manufacturers and soldiers to weigh which capabilities matter most for a given mission. TechEx receives constant feedback and requests from the units that use its drones, which inform its decisions about what to build. It has a technical support department, which Oleg says works with more than 100 units.

It results in weekly changes to products ranging from small updates to major alterations. Feedback, along with field testing by military pilots and operators, is critical to the work the company does, and has led it toward counterintuitive approaches, away from what it had initially thought would work best and would be what units want. For instance, the prototype of the company's Striker interceptor drone was originally much bigger, with a 1.5-kilogram payload, but testing and feedback showed it needed to be smaller and more agile and didn't need such a large payload.

"We were able to completely redesign, and let's say eventually it looked nothing like the initial prototype," Olha said. Developing new weapons of war is a constant process of reevaluating, rethinking, and evolving.