Starliner OFT-2 Now Targeted for May 19

The launch of Boeing’s CST-100 Starliner spacecraft atop a United Launch Alliance Atlas V rocket on the company’s second uncrewed OFT-2 (Orbital Flight Test-2) for NASA’s Commercial Crew Program is targeted for 6:54 p.m. EDT, Thursday, May 19, from Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida.

The uncrewed mission will test the end-to-end capabilities of the Starliner spacecraft and Atlas V rocket from launch to docking and return to Earth at one of five designated landing zones in the western United States. Following successful completion of the OFT-2 mission, NASA and Boeing will determine a launch window for NASA’s Boeing Crew Flight Test (CFT), Starliner’s first flight with astronauts aboard.

OFT-2 and CFT will provide valuable data toward NASA certifying Boeing’s crew transportation system for regular flights with astronauts to and from the space station.

The OFT-2 flight was scrubbed last August when an unexpected valve position indication in the propulsion system was detected during an electrical storm at the Cape.

The investigation into the valve issue showed that the most probable cause of the valve malfunction was the interaction of moisture with nitrogen tetroxide that permeates through the Teflon seal in the valve, leading to corrosion. To combat this issue, the team designed a purging system that has been integrated into the spacecraft to protect the valves from potential exposure to moisture at the factory, launch complex, and launch pad.

Boeing determined that the service module originally intended for use on OFT-2 would be replaced by the spacecraft it was building for the first crewed flight test. The launch has been further delayed by something of a traffic jam at the International Space Station, including the Axiom-1 private mission and multiple crew rotation and commercial resupply missions to the station.

(Source: Boeing. Image provided)