The launch countdown clock located at Kennedy Space Center press site showing the crew flight test 1 patch design. Image by Richard Gallagher
Cape Canaveral, FL – As anticipation builds for this Saturday’s launch of Boeing’s Starliner spacecraft, the aerospace community is excited and cautiously apprehensive. The Crew Flight Test (CFT), which will send NASA astronauts Butch Wilmore and Suni Williams to the International Space Station (ISS), will be a big achievement for Boeing and NASA’s Commercial Crew Program. However, this historic mission has not been without its challenges, due to multiple delays and critical repairs preceding the upcoming launch attempt.
Persistent Delays and Technical Hurdles
Advertisement
The Starliner mission has faced numerous setbacks since its inception, with both technical issues and external factors contributing to delays. Initially scheduled for July 2023, the launch was postponed due to problems with the spacecraft’s parachute system and the discovery of flammable tape used extensively within the vehicle. These issues necessitated a comprehensive review and extensive modifications, including the removal of over a mile of hazardous tape and reinforcement of the parachute system to handle off-nominal landing loads (Space.com).
The Boeing Starliner Spacecraft attached to a ULA Atlas V rocket on LC-41. Image by Richard Gallagher
The launch date was rescheduled for May 6, 2024, but was scrubbed again just hours before liftoff due to a malfunctioning oxygen relief valve on the rocket’s Centaur upper stage. The valve issue, which caused a buzzing sound indicating potential wear nearing its rated life of 200,000 cycles, required careful examination and potential replacement, further pushing the launch to at least May 10th.
During the replacement of the faulty relief valve, engineers investigated a helium leak that was discovered in one of the Starliner’s propulsion modules, specifically a “doghouse” containing the reaction control system (RCS) thrusters. Engineers traced the leak to a flange where propellant lines converge to feed a specific thruster. The issue was identified during normal post-scrub procedures following the May 6th launch attempt.
The Starliner uses helium to pressurize propellant lines, which is crucial for the operation of its RCS thrusters. Testing showed that even if the leak rate increased significantly, the spacecraft could still safely complete its mission due to built-in redundancies. Specifically, the Starliner has multiple thrusters that could compensate for the failed unit, and the affected manifold could be isolated if necessary.
Mark Nappi, Boeing’s Starliner program manager, highlighted that the discovery of the leak, while inconvenient, allowed for a deeper understanding of the system and potential vulnerabilities. This understanding will help improve future spacecraft designs and operational procedures.
Preparations and Repairs
In the lead-up to the rescheduled launch, Boeing’s engineering team and NASA have worked diligently to address these issues and ensure the Starliner is flight-ready. “We have primarily been working on getting the vehicle ready for flight and solving the issues we had back in the summer,” stated John Nappi, Boeing’s Vice President for Starliner (NASA).
Despite the challenges, the spacecraft is now deemed ready for its crewed mission. The rigorous testing and validation processes undertaken by Boeing and NASA have been critical in preparing the spacecraft for its historic journey, ensuring all systems are operational and safe for the crew (NASA).
Astronauts Leading the Mission
The mission will be commanded by NASA astronauts Butch Wilmore and Suni Williams, both seasoned veterans with extensive spaceflight experience.
Nasa astronauts Butch Wilmore and Suni Williams commanding the Starliner spacecraft. By Richard Gallagher
Butch Wilmore, a retired U.S. Navy captain and NASA astronaut since 2000, has previously served on the ISS and commanded Expedition 42. With over 178 days in space, Wilmore brings a wealth of knowledge and expertise to the Starliner mission. Reflecting on the mission, he expressed excitement and gratitude for the opportunity to be part of such a pivotal moment in space exploration. “It’s just a rare opportunity — you almost pinch yourself and say, really, we’re the ones who get to experience this,” Wilmore commented (Boeing).
Suni Williams, also a former Navy test pilot, is renowned for her extensive spacewalk experience and previous missions aboard the ISS, including commanding Expedition 33. With over 322 days in space and 50 hours of spacewalks, Williams is well-prepared to evaluate the new spacecraft’s systems. She has been actively involved in the Starliner’s development, providing crucial insights during training. “We are very in tune and familiar with all the required operations,” Williams said, emphasizing their readiness for the mission (Boeing).
Looking Forward
The Starliner’s Crew Flight Test represents a big leap forward in NASA’s goal to maintain a robust presence on the ISS and enhance its commercial partnerships. Once certified, the Starliner will join SpaceX’s Crew Dragon in providing transportation for astronauts to and from the ISS, ensuring redundancy and flexibility in missions.
As the countdown to Saturday’s launch continues, the focus remains on safety and ensuring every detail is meticulously checked and rechecked.
