This story was updated Aug. 26.

WASHINGTON — An Orbital ATK Minotaur 4 rocket lifted off from Cape Canveral, Florida, early Saturday morning, carrying the U.S. Defense Department’s Operationally Responsive Space (ORS)-5 satellite. The launch comes as a debate is flaring up again about whether companies should be able to use converted surplus intercontinental ballistic missile (ICBM) motors to launch commercial satellites.

Rekindling the argument is a U.S. Government Accountability Office (GAO) report released this month examining the pros and cons of such a course and provides plenty of fodder for both sides.

While surplus ICBM motors can be used for government launches like the one Orbital ATK conducted this morning, the 1998 Commercial Space Act forbids their use for commercial launches. The U.S. Air Force has a stockpile of about 720 surplus motors, the GAO says in its Aug. 16 report, “Surplus Missile Motors, Sale Price Drives Potential Effects on [Defense Department] and Commercial Launch Providers.”

Changing the law to allow the use of surplus ICBM motors for commercial space launch could give U.S. companies more domestic options for sending small satellites to low-Earth orbit while making U.S. launch companies more globally competitive, the GAO says. Commercial rockets used surplus ICBM solid rocket motors could also provide launch customers with more service options and greater schedule flexibility, according to the report.

But the GAO notes the sole beneficiary of such a policy change appears to be Orbital ATK, currently “the sole U.S. provider of ICBM motor-based space-launch vehicles.”

The Minotaur 1, first launched in 2000, uses two surplus Minuteman 2 motors and the Minotaur 4, first launched in 2010, uses three Peacekeeper motors.

After waiting out a weather delay, Minotaur 4 lifted off Aug. 26 at at 2:04 a.m. EDT from Cape Canaveral’s revamped Complex 46, which was last used for a launch in 1999 amd is next scheduled for launch use in 2019 when NASA tests the Orion crew capsule’s abort system.

The launch was Minotaur’s first from Florida. Previous Minotaur launches have been conducted from Alaska, California and Virginia.

The Minotaur 4 carried the Air Force’s 113-kilogram ORS-5 satellite, known as SensorSat, into a low-inclination orbit from where it will track satellites and other space objects in higher orbits. The ORS-5 system cost $87.5 million, the Air Force says, including $49 million for the satellite and $11.3 million for its ground system. Orbital ATK’s $27.2 million launch contract, awarded in 2014 after no other launch venture was deemed qualified to bid, was about $7 million more than ORS officials initially expected to spend to put ORS-5 in orbit.

Orbital ATK’s competitors are concerned, though, that relaxing restrictions on surplus ICBM motors could help Orbital ATK drive down costs for commercial launches of small satellites. The company is already pushing its Minotaur-C, an upgraded Taurus rocket whose only scheduled flight is an Oct. 18 launch from Vandenberg Air Force Base, California, with six SkySat Earth-observation satellites for commercial-imaging company Planet.

Orbital ATK builds Castor 120 motors in house for the Minotaur-C but wants to replace them with surplus Peacekeeper motors in order to offer cheaper commercial launches, said Barron Beneski, Orbital ATK vice president of corporate communications. “Whether it would be a Minotaur-C or something we would rebrand, I don’t know.”

Some in the launch industry, GAO notes, say that if the Air Force is allowed to sell the surplus motors, it should offer the Peacekeeper motor set at the market price of the Castor 120 they would replace, or about $11.2 million. But at least one party – Orbital ATK won’t say if it was them – told government officials the Air Force should sell a Peacekeeper motor set for $1.3 million, significantly less than what it would cost the Air Force to refurbish and transfer the motors to Orbital ATK.

While it looks like the Air Force likely would not offer the motors at such a cut-rate price — there are concerns any below-cost pricing would violate U.S. international trade agreements — launch competitors fret that any kind significant savings the government would offer could send the wrong signal to the reemerging U.S. commercial launch industry.

“This is exactly the wrong time to start intervening in the commercial launch industry,” said Richard DalBello, vice president for business development and government affairs for Virgin Orbit, a Long Beach, California company targeting the small-satellite market with an air-launched rocket. “Especially in a way that can pick winners and losers.”

“The GAO points out a change in policy could have a significant negative result,” said DalBello, who helped organize the Next-Generation Launch Coalition, a group of companies that oppose relaxing the restrictions on surplus motors.

Beneski said if Orbital ATK were permitted to buy the surplus motors for commercial launches, it would agree to a case-by-case review process meant to ensure the company wasn’t given unfair advantage in commercial launch competitions.

Beneski also said Minotaur-class rockets are generally overpowered for small satellite launches, adding that Orbital ATK would be going after customers needing to launch satellites weighing at least 1,000 kilograms.

Still, Department of Commerce officials have warned that allowing broader motor sales could disrupt competition by lowering costs for a select group of launch providers. NASA officials told the GAO that allowing motor sales may stifle commercial space innovation.

But Beneski said U.S. launch providers that have been losing cubesat contracts and other small payload customers to foreign competitors should not fear the Minotaur rocket family, which is meant for bigger payloads.

“What they are worried about is secondary payloads,” Beneski said “We’re not their competition. India just launched a hundred of them.”

In February, India’s PSLV rocket launched 101 cubesat-class spacecraft — 88 for San Francisco-based Planet and eight for neighbor Spire — into addition to the primary payload, the Cartosat-2D imaging satellite, and two smaller Indian satellites.