Starliner makes a safe landing—now NASA faces some big decisions [1/4] - Boeing Starliner 2.jpg (1/1)

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Contract says a docking demonstration is needed. Will NASA waive this
requirement?

Boeing’s Starliner spacecraft safely returned from orbit on Sunday morning,
landing at White Sands Space Harbor in New Mexico before sunrise. The capsule
very nearly hit its bullseye, and initial reports from astronauts on the scene
say the vehicle came through in "pristine" condition.

The company will now spend several days preparing Starliner for transit, before
shipping it from New Mexico back to Boeing's processing facility at Kennedy
Space Center in Florida. Then, engineers will spend most of January reviewing
data captured by on-board sensors. What happens after that is the big question.

Mission Elapsed Time anomaly

After the spacecraft launched on board its Atlas V rocket, but before it
separated from the booster, the capsule needed to figure out what time it was.
According to Jim Chilton, Boeing's senior vice president of the Space and Launch
division, the way this is done is by "reaching down into" the rocket and pulling
timing data out. However, during this process, the spacecraft grabbed the wrong
coefficient. "We started the clock at the wrong time," Chilton said. "The
spacecraft thought she was later in the mission and started to behave that way."

The net effect of this is that Starliner's service module thrusters began
consuming a lot of propellant to keep the vehicle in a very precise attitude
with respect to the ground. When flight controllers realized the error, it took
time to establish a communications link because the spacecraft what not where
they thought it was.

With the on-board propellant remaining, Starliner did not have sufficient
reserves to approach the International Space Station and perform a rendezvous
and docking with the orbiting laboratory—a key objective of this flight test
before NASA allows its astronauts to fly on the capsule into space.

Much of the rest of the flight went very well, however, once flight controllers
diagnosed and corrected the mission elapsed time error. (The clock was off by 11
hours.) The vehicle flew smoothly in orbit, its life support systems kept the
spacecraft at good temperatures, and it made a safe and controlled landing on
Sunday morning. Chilton said he believes the vehicle will meet 85 to 90 percent
of the test flight's objectives.



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