SpaceX has reset the launch of a crucial test flight of the Dragon capsule for no earlier than Nov. 18, giving engineers extra time to simulate the ship's brief but ambitious mission.

The second Falcon 9 rocket undergoes a fueling test in September. Credit: SpaceX

The 10-day slip from the flight's last liftoff date, Nov. 8, is geared toward ensuring the mission has a better chance at success, according to SpaceX.

"We will launch when we believe the vehicle is ready and there is more testing that would yield a meaningful improvement in mission success," the company said Monday in a statement released to Spaceflight Now.

The launch window on Nov. 8 was between 1430 GMT (9:30 a.m. EST) and 1752 GMT (12:52 p.m. EST).

According to SpaceX, the Falcon 9 rocket has backup launch opportunities on Nov. 19 and Nov. 20. The schedule move leapfrogged a Nov. 15 Delta 4-Heavy rocket launch with a national security payload.

If launch remains scheduled for Nov. 18, engineers plan to roll the 154-foot-tall Falcon 9 rocket to the launch pad for a preflight engine firing Nov. 13.

The SpaceX launch team completed a fueling test of the two-stage rocket Sept. 15.

But officials are not ruling out another delay.

"Dragon is an entirely new vehicle, making it impossible to predict exactly when all tests and verification of test data will be complete," the SpaceX statement said.

SpaceX is processing their first payload with toxic hydrazine and nitrogen tetroxide propellants at launch pad 40 at Cape Canaveral, Fla. Officials say they are taking extra precautions with the introduction of hypergolic fuel.

The schedule uncertainty is focused on maximizing the odds of success on the Dragon test flight, which is slated to complete between one and three orbits of Earth, or last roughly two to five hours.

"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 problems," the statement said. "So far, it looks good, but we want to triple check."

The upcoming flight follows a wildly successful first launch of the Falcon 9 rocket in June. That launcher carried a dummy Dragon capsule into orbit.

The Dragon spacecraft mounted on a processing fixture inside the SpaceX hangar at Cape Canaveral, Fla. Credit: Brian Attiyeh/SpaceX

Speaking to reporters Monday at Kennedy Space Center, NASA's chief space operations official said SpaceX is working on verifying the interaction of the vehicle's software and hardware.

"They have some hardware integration tests where they check out their hardware with their software," said Bill Gerstenmaier, NASA's associate administrator of space operations. "They wanted some additional time to do that, so that's why they moved from the 8th to the 18th."

SpaceX is developing the Dragon capsule and Falcon 9 rocket under an agreement with NASA. The design was completed using a mix of federal and private investment in the Commercial Orbital Transportation Services program, an initiative to procure U.S. spacecraft to deliver cargo to the International Space Station.

"They are doing all the right things," Gerstenmaier said. "They have got the right attitude of how to get ready for flight."

Next month's mission is an all-in test flight of the Dragon, demonstrating for the first time its guidance and navigation system, orbit maneuvering thrusters, flight software, heat shield and parachutes.

After launching into space aboard a Falcon 9 rocket and circling Earth a handful of times, the Dragon will drop back into the atmosphere and parachute into the Pacific Ocean off the coast of Los Angeles.

"They have a pretty aggressive first flight," Gerstenmaier said.

The mission's success will determine whether NASA approves a SpaceX proposal to combine the next two Dragon demonstration flights in 2011. The baseline Dragon manifest calls for a second mission to approach the space station to check the craft's rendezvous systems, then a third Dragon spacecraft would be grappled by the outpost's robotic arm and berthed to the complex.

SpaceX hopes to send the second Dragon flight all the way to the space station, accomplishing both flights' test objectives and expediting the first operational mission to delivery supplies.

Dennis Stone, the manager of integration in NASA's commercial crew and cargo office, said the space agency will decide whether to consolidate the next two Dragon flights after reviewing the results of the November mission.

The company has a contract with NASA for up to 12 cargo flights valued at up to $1.6 billion.