PARIS — Satellite fleet operator SES of Luxembourg said it has used U.S. citizens to look deeply into the Falcon 9 rocket’s Sept. 29 upper-stage-restart malfunction without trespassing on U.S. technology-export restrictions.

The restrictions, commonly known as ITAR, or the International Traffic in Arms Regulations, limit non-U.S. access to information about rocket issues, even when the personnel in question are the customers paying for the rocket’s launch.

Space Exploration Technologies Corp. (SpaceX)’s Sept. 29 mission was supposed to include a demonstration of the ability of its Merlin 1D engine’s ability to restart a second time, a function that was not needed for the Sept. 29 launch but will be necessary for the launch of the SES-8 satellite.

The Merlin 1D did not complete a second burn because its igniter-fluid lines were frozen by proximity to liquid oxygen. The multiple engine restarts conducted during ground testing did not face this problem because the ambient air was warmer than the conditions found in orbit.

SpaceX has placed thermal insulation over the lines to prevent a recurrence.

In a Nov. 24 press briefing, SES Chief Technical Officer Martin Halliwell said SES has been able to learn all it needed to know about the Falcon 9 in general, and specifically about the non-restart issue, by having U.S. passport holders “embedded” with SpaceX.

“We’ve had extraordinary access to the analysis work, the engineering work that’s been done on the upper stage … the mitigation and the mitigating factors,” Halliwell said. “We’ve had our crews actually crawling around the engine space. They’ve been embedded together with the SpaceX propulsion team, and … that’s enabled us to retire an awful lot of risk.

“For this particular mission we have U.S. citizens who were able to work absolutely hand in hand together with our colleagues at SpaceX. That information and the specifics of the rework [on the upper stage] have not been extended to non-U.S. citizens, of course. But they were able to indicate to us that basically we’re ready to go.”

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Peter B. de Selding was the Paris Bureau Chief for SpaceNews.