WASHINGTON — Hawthorne, Calif.-based Space Exploration Technologies (SpaceX) has slipped a planned Nov. 8 launch of its Falcon 9 rocket and Dragon cargo vessel to Nov. 18 to allow for more testing.

SpaceX spokeswoman Kirstin Brost said there was “no single reason” for the date change.

“We would like to do more integrated system testing including another in-depth round of hardware in the loop mission simulations to see if we can uncover any corner case problem,” Brost said in an Oct. 25 e-mail, referring to problems that occur only outside of normal operating parameters. “So far it looks good, but we want to triple check.”

Brost said SpaceX is targeting a Nov. 18 launch with Nov. 19 and 20 reserved as backup dates.

The flight, a demonstration of SpaceX’s medium-class rocket along with its cargo-carrying space capsule being developed under NASA’s Commercial Orbital Transportation Services (COTS) program, was originally slated to occur in September 2008 per the company’s 2006 NASA Space Act Agreement. The document was later modified to reflect a June 2009 initial demonstration flight. Routine resupply runs to the international space station were expected to follow as early as December of this year under a fixed-price contract worth $1.6 billion, but hardware development has taken longer than planned.

The first COTS demo will be a four-hour flight meant to show Dragon can complete as many as four orbits, transmit telemetry, receive commands, maneuver, re-enter the atmosphere and make a safe water landing for recovery.