Carefully timed space shuttle flights from NASA to avoid what?

Answer: New Year's Eve

While the launch of men and women into space by nature seems highly technological and futuristic, NASA's Space Shuttle program featured many Elements of this were downright anachronistic as the shuttles retired. One of the side effects of operating a spacecraft with computer chips from the 1

980s and code from the 1970s was a very cautious attitude to events that may have introduced unknown variables or factors for which the computer system was not properly programmed.

It was the utmost caution and desire to safely bring home any crew that caused NASA to approach the annual rollover from December 31 to January 1 with a stance that was "better than forbearance" was. The engineers were particularly worried that the Year-End Rollover event (YERO) could cause disruption to the flight software that could endanger the crew. Even when they conducted extensive testing in 2007 and developed a solution to ensure safety, they remained cautious.

Over the period of 135 shuttle flights between 1981 and 2011, no shuttle has ever been launched in space. or led to New Year to avoid unforeseen problems with the on-board systems.