Boeing Starliner Landing: What You Need to Know

For NASA, attempting to put a capsule down on land is unusual. All previous landings of its capsules — the Mercury, Gemini and Apollo programs of the 1960s and 1970s — were in the ocean. After all, you might be safer diving into water than an expanse of sand.

Russian astronauts have always landed on solid ground, and that approach offers advantages. Salt water corrodes metal, which would complicate plans to reuse Starliner capsules for future missions. Also, a capsule hitting an ocean wave at the wrong angle could sink. (That is what happened during testing of Apollo capsules, requiring a revamping of the design.)

The Starliner capsule currently in orbit is scheduled to be used again for a future mission carrying astronauts.

What went wrong on Friday?

Quite simply: Starliner got the time wrong.

When the spacecraft separated from the Atlas 5 rocket that lifted it to space, an incorrect clock caused it to start firing its thrusters and try to get into the position and orientation where it thought it should be.

“She thought she was later in the mission,” Jim Chilton, senior vice president of the space and launch division at Boeing, said during a news conference on Saturday, “and being autonomous, started to behave that way.”

Article source: https://www.nytimes.com/2019/12/22/science/boeing-starliner-landing.html?emc=rss&partner=rss