Boeing’s Starliner ready for Saturday launch to space station, first flight with crew on board
All systems are “go” for a second attempt to launch Boeing’s oft-delayed Starliner crew ship Saturday on a long-awaited test flight to the International Space Station, the capsule’s first with astronauts aboard, NASA managers said Friday.
“From a station standpoint, from our crew, from our ground teams, we are ready to go fly this mission,” said Dana Weigel, manager of NASA’s space station program. “We’re excited that we are on the doorstep of this historic mission.”
United Launch Alliance
Liftoff of the Starliner atop a United Launch Alliance Atlas 5 rocket is targeted for 12:25 p.m. EDT Saturday, roughly the moment Earth’s rotation carries pad 41 at the Cape Canaveral Space Force Station into alignment with the station’s orbit.
mission managers ordered a scrub.
The Atlas 5 was hauled back to ULA’s Vertical Integration Facility where a replacement valve was installed, tested and cleared for flight. In the meantime, Boeing engineers were assessing data collected after the scrub that indicated a small helium leak in plumbing used to pressurize the Starliner’s propulsion system.
The leak eventually was traced to the plumbing leading to a specific reaction control system jet, one of 28 such thrusters mounted around the Starliner’s drum-shaped service module. After extensive tests and analysis, mission managers concluded the spacecraft could safely fly as is with no credible threat to flight safety.
If the leak drastically worsened in flight, the helium manifold in question would be isolated, disabling its thrusters. That would prevent a normal re-entry using more powerful thrusters at the end of the mission, but backup plans are in place to carry out the de-orbit “burn” using two long firings of unaffected RCS jets.
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Source: cbsnews.com