WASHINGTON — Space Exploration Technologies (SpaceX) has postponed a planned Nov. 20 launch of its Falcon 9 rocket and Dragon cargo vessel to no earlier than Dec. 7, according to a company news release.

“SpaceX is targeting December 7th for the first-ever fight of our Dragon spacecraft, with the 8th and 9th as backup dates,” Kirstin Brost, a spokeswoman for the Hawthorne, Calif.-based company, said in a Nov. 8 e-mail. “We are submitting our request to the [U.S.] Air Force today.”

The flight, a demonstration of the medium-class rocket and space capsule being developed under NASA’s Commercial Orbital Transportation Services (COTS) program, was originally slated to occur in September 2008. SpaceX’s COTS agreement 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, but hardware development has taken longer than planned.

Brost did not explain the reason for the schedule change, one of several announced since September. However, SpaceX is still awaiting regulatory approval from the U.S. Federal Aviation Administration (FAA) for the mission. The company submitted its license application more than a year ago, but the FAA is still reviewing data on the Dragon capsule’s planned atmospheric re-entry.

In June, SpaceX conducted a successful fight test of Falcon 9 with a qualification unit of the Dragon spacecraft on board. The next three Falcon 9 missions will carry an operational Dragon cargo vessel in an increasingly complex series of demonstrations under the terms of the company’s $278 million COTS deal. The first such mission calls for Dragon to complete up to four Earth orbits, transmit telemetry data, receive commands, maneuver, re-enter the atmosphere and make a safe water landing in the Pacific Ocean for recovery.

Upon successful completion of the demo missions, SpaceX will begin making regular cargo-delivery runs to the international space station under a separate fixed-price contract valued at $1.6 billion.

Meanwhile, SpaceX notified the U.S. Securities and Exchange Commission Nov. 9 that it has raised $50.19 million in new equity financing from 16 investors.

The investors were not named in the filing, and SpaceX would only identify them as existing shareholders. “Our existing investors are bullish on the future of SpaceX and asked if they could invest more,” Brost said via e-mail Nov. 10. Elon Musk, SpaceX’s founder and chief executive, is the company’s largest shareholder. Other shareholders include fellow PayPal co-founder Luke Nosek, managing partner of the Founders Fund of San Francisco, and venture capitalist Steve Jurvetson of Menlo Park, Calif.-based Draper Fisher Jurvetson.