Boeing Starliner ISS docking delayed

Boeing’s Starliner capsule is making a delayed docking attempt with the International Space Station on Thursday, after NASA called off an initial approach to analyze an issue with the spacecraft’s propulsion system.

The spacecraft was scheduled to dock with the ISS at 12:15 p.m. ET, but NASA flight controllers called off the approach and instructed the astronauts aboard to hold the spacecraft 200 meters (or about 650 feet) away from the space station.

Starliner has 28 jets, known as its reaction control system (RCS) engines, that help the spacecraft make small movements in orbit. NASA was troubleshooting five of the jets that were not operating and was able to recover four of the malfunctioning jets after testing.

The spacecraft is making a second attempt at docking, scheduled for 1:33 p.m. ET, after NASA cleared Starliner to approach with 27 of the 28 jets operational.

NASA astronauts Butch Wilmore and Suni Williams have been working with NASA’s flight controllers to test fire the thrusters in an attempt to recover the spacecraft’s full propulsion system.

Wilmore and Williams were told by NASA capsule communicator, or CAPCOM, Neal Nagata that the 12:15 p.m. docking attempt had to be called off due to the ISS’ zero fault tolerance for a spacecraft control problem.

CAPCOM Nagata had the astronauts hold the spacecraft beyond the “keep out sphere,” an invisible boundary around the ISS that serves as a safety measure, while diagnosing the problematic thrusters.

Boeing’s Starliner launched successfully on Wednesday to begin the crew flight test, marking the first time the capsule is carrying astronauts to space. The mission represents the final major step before NASA certifies Boeing to fly crew on operational missions.

The spacecraft was once seen as a competitor to SpaceX’s Dragon. However, various setbacks and delays have steadily slipped Starliner into a backup position for NASA, with the agency planning to have the companies fly astronauts on alternating missions.