Space Exploration Technologies (SpaceX) is reviewing a helium leak on the first stage of its Falcon 9 v1.1 rocket that was discovered May 9 during fueling at Cape Canaveral AFS, Fla. 

The Hawthorne, Calif.-based company says the leak prompted engineers to scrub a May 9 static fire test of the rocket and postpone the May 10 launch of six small communications satellites for New Jersey-based fleet operator Orbcomm until June 11.

SpaceX says the helium leak has been traced to an area different from that of a previous first-stage gas leak that delayed an April launch of the company's third NASA Commercial Resupply Services (CRS-3) mission to the International Space Station (ISS).

“The issue was a helium leak in a different location that wasn't present during earlier tests,” SpaceX spokeswoman Emily Shanklin said in a May 20 statement to Aviation Week. “The stage was undamaged and remained at the Cape; we are thoroughly reviewing the stage before clearing it for flight, as we want to make sure that no further such issues occur.”

Shanklin said SpaceX is aiming to launch the six second-generation Orbcomm (OG2) satellites June 11, with June 12 as a backup.

The launch is to be the first of two missions for Orbcomm this year as the company builds a constellation of 17 second-generation machine-to-machine communications satellites in low Earth orbit. In addition to the six spacecraft expected to blast off this month, SpaceX is expected to deliver the remaining 11 by year's end.