Spacecraft thrusters tested and helium system checked in second successful docked hot fire test.
The Starliner team completed a docked hot fire test of the spacecraft’s Reaction Control System (RCS) thrusters Saturday afternoon, and monitored its helium system, providing additional data points for the Crew Flight Test’s return to Earth.
With Starliner flight director Chloe Mehring at the helm and Boeing engineers on console monitoring the spacecraft’s systems, flight controllers commanded the sequential firing of 27 RCS thrusters.
“The integrated teams between Starliner and ISS worked extremely well together this week to finalize and safely execute the docked hotfire sequence,” said Mehring, who will lead the Starliner flight control team in the upcoming undocking from the International Space Station.
“Both teams were very happy with the results.”
The one-pulse firings were designed to confirm the performance of each thruster. Aft-facing thrusters were fired for 1.2 seconds and all others for .40 seconds. Between each firing, the team reviewed real-time data and all thrusters performed at peak thrust rating values, ranging from 97-102%. The helium system also remained stable. Additionally, an RCS oxidizer isolation valve that was not fully seated previously, was cycled several times during today’s testing and is now operating normally.
This is the second time the spacecraft has been hot fired successfully while docked, an integrated operation the station and Starliner teams will also conduct during future long-duration missions.
Flight test astronauts Butch Wilmore and Suni Williams were inside Starliner Calypso giving the team on the ground real-time feedback during the test. In preparation for the return home, Wilmore and Williams will participate in two undock to landing simulations next week.
A Flight Test Readiness Review is tentatively planned for late next week, and the data gathered today will be reviewed and included in return flight rationale. While a landing date has not yet been set, opportunities are available throughout August.