WASHINGTON — The U.S. State Department has revised an export control rule to clarify that spacecraft and their thrusters should not be classified as rocket engines, as some companies have been doing.

The new rule, released Oct. 4 on the Federal Register, results from confusion among satellite and space hardware manufacturers from reforms meant to relax some export control laws in 2014 and 2017, according to the State Department.

Previous rules under U.S. International Traffic in Arms Regulations (ITAR) classified satellites and their thrusters as rocket engines, resulting in strict, weapons-level control of their sale to non-U.S. buyers.

Since then, satellite and space hardware manufacturers have classified the same thrusters under both ITAR and the Commerce Department’s less stringent Export Administration Regulations, or EAR, the State Department said.

The State Department said that satellites and their thrusters can have some characteristics of other ITAR-controlled technologies, but acknowledged “such thrusters are not rocket or missile power plants per se.”

The State Department specified that the section of ITAR that companies were using that pertains to launch vehicles — which ITAR grouped with missiles, torpedoes and other weapons — specifically “does not control such thrusters” used for spacecraft. Whether thrusters fall under ITAR or EAR depends on specifics such as how much thrust they produce and what propellants they use.

U.S. satellite manufacturers and hardware suppliers have for years said ITAR was overbroad and inhibited their business overseas. Though the reforms made in recent years have made it easier to export non-military space hardware, many aerospace companies want to see further easing of the rules.

“Everyone understood, and I think the government really understood, that they weren’t going to get everything right, right away,” said Dennis Burnett, a consulting principal at LMI Advisors. “They wanted to get as much right as they could and they knew things like this would happen where they would have to have industry come in and tell them ‘you need to fix this.’ You can see they are willing to do that when they are told there is a problem.”

ITAR’s rules, even if sometimes vague, can cost companies millions of dollars if violated, leading companies to err on the side of caution when classifying their products.

“Some people are very afraid that they are going to run afoul of ITAR and they are highly dependent on government work and are not going to do anything to jeopardize that,” Burnett said.

While the new categorization went into effect Oct. 4, the State Department is taking comments until Nov. 19.