The launch of Boeing’s Starliner, which was set for its crewed maiden voyage, was abruptly scrubbed just minutes before liftoff on Saturday. The spacecraft was scheduled to launch atop an Atlas V rocket at 12:25 p.m. ET from Cape Canaveral Space Force Station in Florida, carrying veteran NASA astronauts Butch Wilmore and Suni Williams.
Details of the Scrub
An automatic hold triggered by the ground launch sequencer stopped the countdown clock at 3 minutes and 50 seconds. Following this, the astronauts were safely extracted from the capsule and returned to crew quarters to await further instructions.
NASA announced late Saturday that the launch would not be attempted on Sunday. The next available opportunity is Wednesday at 10:52 a.m. ET, although it has not yet been confirmed if the launch will proceed then. Another backup window is available on June 6.
Technical Issues
Tory Bruno, president and CEO of United Launch Alliance (which built the Atlas V rocket), stated that teams would need to assess the ground launch sequencer issue once the rocket is drained of fuel. The issue involved a triple-redundant computer system where one computer was slow to come online, triggering a red line and an automatic hold.
Earlier, around 10 a.m. ET, mission teams reported a loss of data from ground valves responsible for replenishing liquid oxygen and hydrogen to the upper stage of the rocket. This caused a delay in closing the hatch after the astronauts entered the capsule. The issue was resolved by switching to a redundant system, and the countdown resumed without safety concerns for the crew.
Mission Goals
The mission, called Crew Flight Test, aims to validate Boeing’s Starliner as a viable alternative to SpaceX’s Crew Dragon for ferrying astronauts to the International Space Station (ISS) under NASA’s Commercial Crew Program. When Starliner eventually launches, it will mark the sixth inaugural journey of a crewed spacecraft in US history. Suni Williams will make history as the first woman to fly aboard such a mission.
Activities on the ISS
Once in orbit, the Starliner crew capsule will separate from the Atlas V rocket and fire its own engines, spending over 24 hours traveling to the ISS. The astronauts will test various aspects of the spacecraft’s capabilities, including thruster performance, spacesuit functionality, and manual piloting. They will join seven astronauts and cosmonauts on the ISS for an eight-day mission, testing Starliner’s “safe haven” capability, designed to offer shelter if there is a problem on the space station. Williams and Wilmore will return to Earth in the same Starliner capsule, landing at a site in the southwestern United States, with the earliest possible return on June 10.
Series of Delays
The mission has faced numerous delays due to development issues, test flight problems, and other setbacks. Recently, engineers identified a valve issue and a small helium leak within the spacecraft service module, both of which were deemed manageable. Additionally, a “design vulnerability” in the propulsion system was identified and addressed with a backup plan for the deorbit burn.
Preparing for Launch
After a flight readiness review, all systems, facilities, and teams supporting the test flight were verified for launch readiness. NASA and Boeing also assessed Starliner’s parachutes following a recent parachute issue with Blue Origin’s suborbital flight, concluding that Starliner’s parachutes were “good to fly.”
Last-Minute Adjustments
A recent failure of a pump on the ISS’s urine processor assembly led to a quick swap of a replacement pump into Starliner’s cargo. This required removing two crew suitcases to accommodate the pump, with the astronauts using contingency supplies on the ISS.
Final Thoughts
Despite the setbacks, both NASA and Boeing are optimistic about the mission. Mark Nappi, vice president and program manager of the Commercial Crew Program at Boeing, stated, “We look forward to flying this mission. This is a test flight; we know we’re going to learn things. We are going to improve, and that improvement starts with the Starliner-1 mission and it will be even better than the mission we’re about to fly.”
NASA astronaut Mike Fincke emphasized the astronauts’ confidence in the mission, stating, “Butch and Suni have every confidence in our rocket, our spacecraft and in our operations teams and leadership management teams, and they are definitely ready to go.”