NASA and Boeing are diligently working through a series of "complicated" issues as they prepare for the historic first test flight of the Starliner spacecraft with astronauts on board. The mission, known as Crew Flight Test (CFT), is scheduled for June 1, but the launch date may be subject to change due to ongoing challenges.

One of the major setbacks faced by the team is a small helium leak that was detected in the Starliner spacecraft. Although the leak is relatively minor, its potential impact on the pressurization of the propulsion system during small maneuvers in orbit has prompted careful consideration from NASA and Boeing officials.

Addressing this issue has been time-consuming, leading to limited updates from the team in recent weeks. A delta flight readiness review on May 29 will be conducted to assess the leak and consider potential changes, including the possibility of a deorbit burn if necessary. This review is distinct from the standard flight readiness review due to the altered human certification document for CFT resulting from the leak.

The Starliner's launch was originally scheduled for May 6 but was delayed due to an oxygen relief valve problem on the Atlas V rocket. The valve was subsequently replaced, allowing the mission to proceed. However, the discovery of the helium leak after the launch scrub caused further delays and rescheduling, pushing the earliest possible launch date to June 1.

In a teleconference, officials from NASA and Boeing assured the public that the helium leak, though concerning, is a common anomaly experienced by all human-rated spacecraft systems. They emphasized that if such a leak were to occur in space, it could be managed effectively. Nonetheless, both organizations are working together to identify potential solutions and prevent reoccurrence of the issue in future missions.

The leak originates from a rubber seal within a flange, which helps facilitate the passage of helium between two metal parts. Located in one of the Aerojet Rocketdyne reaction control system (RCS) thrusters, the leak has gradually increased in intensity. Although engineers could not physically access the leak during the stack configuration of the Starliner, they have been utilizing software tools to analyze its behavior.

NASA, Aerojet Rocketdyne, and Boeing are currently exploring approximately five potential solutions to address the leak. However, they acknowledge that helium is prone to leaking due to its molecular size. The leak has grown from 7 psi to between 50 psi and 70 psi, but extensive analysis indicates that Starliner can handle additional thruster leaks, and the system remains stable during pressure changes.

An unexpected outcome of studying the helium leak has been the revelation of a design vulnerability within the propulsion system. As a result, contingency measures have been put in place to ensure the spacecraft's safe return to Earth. In the case of the loss of multiple thruster manifolds, a secondary method has been devised to perform a deorbit burn using four RCS thrusters in two separate burns, spaced 80 minutes apart.

The upcoming delta flight readiness review will primarily focus on the human certification aspect of Starliner, taking into account the changes implemented in response to the helium leak issue. The review will also allow the team to thoroughly assess the fixes for the leak after the team's Memorial Day weekend break.

While June 1 remains the target launch date, it is subject to change as work on the issues continues. Backup launch dates in the near term include June 2, June 5, and June 6, with additional opportunities available throughout the early summer. Despite any potential delays, both NASA and Boeing assure that the Starliner spacecraft will remain stable for an extended period.

Should the launch be postponed, the International Space Station (ISS) program manager, Dana Weigel, stated that there is flexibility throughout the summer to accommodate the mission. The ISS docking port designated for CFT is exclusively allocated to Starliner, but alternatives exist until crew rotation activities in August. If the CFT astronauts are on board the ISS during that time, they may assist with unloading activities if time allows.

NASA astronauts Butch Wilmore and Suni Williams, both former U.S. Navy test pilots, are scheduled to be on board the Starliner for the CFT mission. The crew has been in quarantine for approximately a month and remains in good spirits despite the delays. Their expertise and experience with developmental programs like Starliner contribute to their adaptability in dealing with schedule changes.

As the team continues to address and mitigate the issues surrounding the helium leak, the Starliner's historic first test flight with astronauts draws closer. The joint efforts of NASA and Boeing aim to ensure a successful and safe mission, marking a significant milestone in the development of commercial crew capabilities for the future of human space exploration.