SpaceX cargo delivery test flight slips another month to late April

CBS News

Work to test critical flight software that will be used by a new commercial cargo craft to rendezvous with the International Space Station has forced Space Exploration Technologies -- SpaceX -- to slip its first launch to the lab complex by at least another month, from late March to late April at the earliest, to make sure complex fault routines and other critical components will work properly, officials said Thursday.

"SpaceX is continuing to work with NASA to set a new target date for launch, expected to be late April," the company said in a brief statement. "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."

An artist's rendering of a SpaceX Dragon cargo craft in orbit. (Credit: SpaceX)
Late last month, the company announced that launch of SpaceX's unmanned Dragon cargo ship atop the company's Falcon 9 rocket, originally targeted for Feb. 7, would be delayed to at least the end of March, primarily because of unspecified software testing.

The latest "no-earlier-than" planning date is little more than a placeholder on the Air Force Eastern Range, which orchestrates all launchings from the East Coast. Because of potential conflicts with Russian Progress supply ship dockings and departures and a variety of other factors, sources say, the SpaceX flight could slip into May even if the spacecraft is ready in April.

In an email exchange late last week with Spaceflight Now, company founder and chief executive Elon Musk said an "insane amount of testing" was required to get the craft ready for flight, much of it involving how the flight software responds to faults and errors. For this first flight to the station, the Dragon capsule must fly a separate test approach to verify performance and abort capabilities before closing in for the actual berthing.

"The critical path task is verification of the systems failure/response matrix," Musk told Spaceflight Now. "Dragon is designed to be tolerant of two failures of almost anything. We need to make sure that the fail-over systems work correctly in all scenarios."

Headquartered in Hawthorne, Calif., SpaceX has a $1.6 billion contract with NASA to provide 12 cargo flights to the station for delivery of more than 44,000 pounds of equipment and supplies. The contract may be expanded to cover additional flights, boosting its value to some $3.1 billion.

Three test flights were planned by SpaceX under a separate contract. The first flight was successfully carried out in December 2010 when a Dragon capsule was boosted into orbit atop a SpaceX Falcon 9 rocket and guided to a successful splashdown in the Pacific Ocean. It was the first commercial spacecraft ever recovered from orbit.

As originally envisioned, the second test flight would have tested rendezvous procedures and included a close-approach to the station, but berthing would have been deferred until the third flight. SpaceX successfully lobbied to combine the second and third test flights into a single mission, originally targeting launch for Feb. 7.