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NASA and Boeing Ready for CFT’s Second Attempt

Calypso sits atop its Atlas V N22 launch vehicle ahead of the first attempt to launch CFT. The vehicle was subsequently rolled back to the VIF and serviced before the June 1 attempt.
Credit: David Diebold

NASA’s Commercial Crew Program and provider Boeing are targeting Saturday, June 1 2024 for another attempt to launch the Boeing Crew Flight Test mission, the final step in certifying the Starliner spacecraft for regular flights to the International Space Station. Ongoing analysis of a helium leak on Boeing’s Starliner spacecraft Calypso forced NASA and Boeing to delay the Crew Flight Test after completing a majority of the countdown on May 6th, however, mission planners are now comfortable proceeding forwards to flight. With the crew of Barry “Butch” Wilmore and Sunita “Suni” Williams arriving at Kennedy Space Center on May 28th, all of the components required for launch are now at the Cape for launch.     

The spacecraft will launch atop an Atlas V rocket from United Launch Alliance to dock with the International Space Station for a roughly eight-day stay before returning to Earth. During the countdown on May 6, a pressure relief valve on the Atlas 5 rocket’s Centaur upper stage was behaving off nominally, and the mission was scrubbed about two hours before liftoff. The rocket was rolled back into ULA’s Vertical Integration Facility (VIF) where the valve was replaced, tested and cleared for flight. The anomaly was described as a kind of “chattering”, where a valve was found to  In a post launch attempt press conference on May 6, ULA CEO and President Tory Bruno highlighted that despite being able to launch an uncrewed mission in the vehicle’s observed state, the ULA team did not want to operate outside of laid out safety parameters for crewed flight – highlighting the commitment to safety the company has emphasized throughout the launch campaign.

Commander Barry Wilmore and Pilot Sunita Williams exit the Neil Armstrong Operations and Checkout Building ahead of the May 6th Attempt, which culminated in a scrub.
Credit: JJ Carola

After scrubbing the May 6 launch attempt, a helium leak was detected in the pressurization system that allows the fuel and oxidizer on the Starliner’s Service Module (SM) to flow correctly to their designated thrusters when called upon. The SM features 28 reaction control system (RCS) thrusters and 20 orbital maneuvering and attitude control (OMAC) thrusters. The helium leak was connected to a single RCS thruster and was determined to be within flight limits on May 6. With the stand down to investigate the issues observed on Centaur, NASA Commercial Crew teams and Boeing took additional time to assess the leak observed on Starliner’s SM. While not outside of flight rules, there was some concern about the implications of such a leak on vital propulsion systems – including the powerful abort motors that would be used to propel Starliner and its crew away from the spacecraft in the event of an emergency, as well as on the deorbit burn – the final phase of orbital flight required to bring the crew home to their targeted landing site.  

On Friday, May 24 NASA, Boeing and ULA held an additional press conference to discuss readiness as the teams headed for another attempt at launching Starliner. NASA’s Associate Administrator Jim Free highlighted the hard work of all of the players involved and said that he looked forward to having “dissimilar redundancy” within the Commercial Crew program, something that has been reflected in other parts of the agency, such as ISS resupply and even Human Landing System selection. Steve Stich, manager for NASA’s Commercial Crew Program, went into further detail about the importance of reviewing the data for this helium leak, discussing the importance of understanding the dynamics and possible changes required for operation. Sitch emphasized that the spacecraft was able to handle a leak 100x stronger than the one observed, and the team subsequently came to the conclusion that proceeding into the FRR was acceptable.

Station side, NASA’s Dana Weigel reiterated the ISS program’s commitment to supporting Starliner’s mission, and laid out the schedule of events that had been reshuffled in order to accommodate a changing schedule. EVA support preparations for a series of spacewalks in June were well underway, which will see astronauts exit the Station and perform vital maintenance on the 26 year old laboratory. Progress 86, having recently departed from the ISS’ Poisk module, will be replaced by Progress 88 – scheduled to launch on May 30th. Weigel reiterated that Station scheduling would not be an issue in the near future for Starliner, clearing the vehicle to proceed with final preparations for the CFT mission. 

NASA and Boeing teams polled “go” to proceed with plans to launch CFT  to the International Space Station at 12:25 p.m. EDT Saturday, June 1. During a Delta-Agency Flight Test Readiness Review Wednesday at NASA’s Kennedy Space Center in Florida, leaders from NASA, Boeing, and ULA verified launch readiness, including all systems, facilities, and teams supporting the test flight. With the mission verified for flight, mission planners, support personnel and astronauts can now begin to prepare for what is sure to be an exciting test mission, one which will fulfill the promise of Commercial Crew with two American spacecraft serving the world’s premier orbiting laboratory.

Edited by Beverly Casillas

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