SpaceX hopes to move forward its bid to deliver supplies to the International Space Station to the second test flight of the Dragon capsule next spring, foregoing an extra mission to prove out the cargo ship's rendezvous capabilities.

Artist's concept of Dragon approaching the space station. Credit: SpaceX

Elon Musk, SpaceX's founder and CEO, told reporters Thursday the schedule change will keep the company on track to carry logistics to the station next year, despite schedule delays on the Dragon spacecraft as crews focus their attention on the first flight of the Falcon 9 rocket this week.

SpaceX previously agreed with NASA to fly three demo flights of the Dragon capsule under the Commercial Orbital Transportation Services program. If the test flights go as planned, the company would now only launch two shakedown missions before starting a dozen operational sorties to deliver equipment to the space station.

"We're advancing the objectives of what's called the COTS 2 flight to enable COTS 2 to go all the way to the space station," Musk said. "We don't yet have final approval from NASA on that. We've discussed it with them at length. We're designing the COTS 2 flight to be capable of that, and we are optimistic that we'll clear the various regulatory hurdles to achieve that."

Under the earlier plan, the second Dragon flight would approach within approximately 6 miles of the complex test long-range navigation, rendezvous and radio communications systems. That mission would be scrapped under the new plan.

The capsule won't be ready for its November launch target. The mission should fly in the second quarter of 2011, according to SpaceX.

The third COTS flight was supposed to approach the station and be grappled by its robot arm, but the mission would now be backup for the COTS 2 demonstration, which is also named Dragon C2.

"The second flight is effectively the third flight, if it's successful," Musk said. "The end objective of the COTS program is to deliver cargo to the space station. That end objective doesn't really shift, it's just the flight that it occurs on is one flight sooner."

Musk said the Dragon vehicle for the first COTS demonstration will be ready to ship to the Cape Canaveral launch site in a "month or two," pending final NASA approvals. On that flight, the Dragon will complete several orbits of Earth before falling back into the atmosphere into the Pacific Ocean for retrieval.

Even if Friday's Falcon 9 test launch does not reach orbit, Musk said he would like to put the Dragon payload on the rocket's next flight.

The first Falcon 9 rocket is carrying a stripped-down Dragon test article that will stay bolted to the booster's second stage. The dummy spaceship will radio data back to Earth for several hours before it drains its batteries.