Private Spaceship Flights to Space Station Delayed to Spring & Fall

The launches of two private spaceships to the International Space Station are being pushed deeper into the year to allow more time to test the vehicles and prepare the launch sites, company officials said recently.

California-based Space Exploration Technologies (SpaceX) and Virginia-based Orbital Sciences Corp. are expected to launch their unmanned, privately-built capsules to the International Space Station this year on demonstration flights to test the vehicles' ability to carry cargo to the orbiting complex.

SpaceX's robotic Dragon capsule was originally scheduled to launch to the space station on Feb. 7, but additional testing on the spacecraft was needed. A new targeted launch date has not been announced, but company officials said they are now aiming to launch Dragon in late April.

"SpaceX is continuing to work with NASA to set a new target date for launch, expected to be in late April," SpaceX spokesperson Kirstin Grantham told SPACE.com. "The primary driver for the schedule continues to be the need to conduct extensive software testing. This is a challenging mission, and we intend to take every necessary precaution in order to improve the likelihood of success."

As part of the test flight, SpaceX's Dragon capsule will approach the complex as astronauts onboard the orbiting outpost latch onto it and secure it to the station using a robotic arm.

Orbital Sciences recently announced that the launch of their unmanned Cygnus cargo freighter has been delayed by several months, and will occur no earlier than August or September. Orbital blamed the delays on the Virginia Commercial Space Flight Authority, which is responsible for the work being done to prepare the launch pad at Wallops Island, Va.

Orbital's Antares rocket, which was formerly called Taurus 2, will launch from the Wallops Island spaceport, but construction at the launch pad facilities must be completed and then certified by NASA first, company officials said. If construction wraps up in early March, the certification process could be completed by late April.

Still, Orbital's chief executive David W. Thompson reportedly told investors in a conference call that this new schedule "is not a slam dunk," and is contingent on the successful completion of other critical objectives, according to Space News.

SpaceX's Dragon capsule is slated to launch atop the company's own Falcon 9 rocket from the Cape Canaveral Air Force Station in Florida.

The flights of the Dragon and Cygnus capsules are part of NASA's Commercial Orbital Transportation Services (COTS) program, which is aimed at nurturing the development of robotic vehicles to carry food, supplies and hardware to the International Space Station in the wake of last year's retirement of NASA's space shuttle fleet.

As part of their COTS partnership with NASA, SpaceX will receive up to $396 million for the successful completion of the milestones outlined in their Space Act Agreement. Orbital will receive up to $288 million for meeting all of their goals.

You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.